Patent ID: 12196720

Numbers in the figures denote:10, raft foundation;11, main beam reinforcement cage;12, secondary beam reinforcement cage;13, J-type column base anchor bolt;131, anchor hook;20, reaction frame;21, crossbeam;22, column;221, first flange;23, tie beam;24, auxiliary positioning frame;241, positioning beam;242, locking sleeve;25, ball node;26, node mounting member;261, lower plate;262, upper plate;263, connection bolt;30, tree-shaped spatial node;31, main pipe;32, branch pipe;33, second flange;40, force measurement assembly;401, positioning rod;402, head plate;403, connection base;404, load sensor,405, positioning sleeve;4051, positioning screw hole;4052, positioning bolt;406, positioning plate;41, tension assembly;411, steel stranded rope;412, penetrating telescopic rod;413, position-limiting plate;414, locking buckle;42, pressure assembly;421, pressure telescopic rod;50, steel structure node;51, main pipe of steel structure node;60, axis adjustment device;61, L-type plate;62, adjustment bolt.

DETAILED DESCRIPTION

The technical solutions in some embodiments of the present disclosure will be clearly and completely described below in conjunction with the accompanying drawings in some embodiments of the present disclosure, and it is clear that the embodiments described are only a part of the embodiments of the present disclosure and not all of the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by a person of ordinary skill in the art without making creative labor fall within the scope of protection of the present disclosure.

In actual engineering applications, various branch pipes on a cast steel node interact with each other in the process of stress, and the various branch pipes transmit a combined force to a main pipe, and the main pipe bears the effect of the combined force. While the above prior art is capable of detecting stress on each branch pipe on the cast steel node by a stress testing device, it is not capable of detecting a force situation on each branch pipe at the same time, which makes it difficult to obtain a force situation of the main pipe when each branch pipe is simultaneously stressed, so that a working state of the cast steel node may not be estimated. Since it is difficult to accurately predict whether the working state of the cast steel node is within a safety limit, which leads to the impossibility of formulating a safe and effective countermeasure strategy, there is a huge safety hazard in the engineering application. Therefore, it is desired to solve such a hazard with the embodiments of the present disclosure.

FIG.1is a schematic diagram illustrating an exemplary overall structure of a reaction frame device according to some embodiments of the present disclosure;FIG.2is a schematic diagram illustrating an exemplary overall structure of an exposed reinforcement structure according to some embodiments of the present disclosure;FIG.3is a schematic diagram illustrating an exemplary structure of a tree-shaped spatial node according to some embodiments of the present disclosure;FIG.4is a schematic diagram illustrating an exemplary structure of a steel structure node according to some embodiments of the present disclosure;FIG.5is a schematic diagram illustrating an exemplary structure of a node mounting member according to some embodiments of the present disclosure;FIG.6is a schematic diagram illustrating an exemplary structure of a reaction frame according to some embodiments of the present disclosure;FIG.7is a schematic diagram illustrating an exemplary reinforcement structure of a raft foundation according to some embodiments of the present disclosure; andFIG.8is a schematic diagram illustrating an exemplary structure of a J-type column base anchor bolt according to some embodiments of the present disclosure.

As shown inFIG.1toFIG.8, a tree-shaped spatial node30may include a straight cylindrical main pipe31, a plurality of straight cylindrical branch pipes32that are fixedly mounted at a top of the main pipe31, and each branch pipe32may be tilted upwardly or in a plumb arrangement, so a dendritic structure may be formed at the top of the main pipe31. The tree-shaped spatial node30may be used to connect and support columns22and crossbeams21in a frame structure. The main pipe31may be a member that is arranged in a plumb manner and may be secured to steel and concrete columns pre-buried in the soil. The branch pipe32may be a member that is secured in sequence with each connection end in the frame structure, correspondingly.

In some embodiments, there is also a second flange33coaxially welded to the bottom of the main pipe31to mount the tree-shaped spatial node30on a raft foundation10through a conventional flange connection manner. More information on the raft foundation may be found in a later description.

In some embodiments, a length, a diameter, and an inclination angle of each branch pipe32may be the same, or there may be different. A diameter of the main pipe31may be typically larger than the diameter of the each branch pipe32to facilitate a higher support force for the branch pipe32.

In a conventional design process, the main pipe31and the branch pipe32may be usually made of cast steel material. During a casting process, a casting model may be constructed in advance according to design requirements, and then the cast material may be poured into the casting model, and the complete tree-shaped spatial node30may form when the cast material is cooled and shaped.

The tree-shaped spatial node30may be typically used as a support leg to provide a stable and reliable support for some large frame structures to stand safely on the ground. In some embodiments, each branch pipe32in the tree-shaped spatial node30may be fixedly connected to each connection end in the frame structure in a sequence, respectively. Meanwhile, the main pipe31may be arranged in a plumb manner and solidly coupled to steel and concrete columns pre-buried in the soil to form the support leg for the frame structure. The steel and concrete columns may be concrete columns with rebar as a skeleton. A fixed connection may be to connect fixedly, which refers to a connection with no relative motion between parts. Exemplary fixed connections may include welding, a threaded connection, riveting, etc.

In some embodiments, the tree-shaped spatial node30may be molded using an integral casting, which has high stiffness and good integrity, excellent fatigue as well as seismic performance, and good workability and adaptability, and may be processed to produce a complex and varied shape according to the needs of the building.

In some embodiments, the tree-shaped spatial node30may be a steel structure node50. A reaction frame20may include a node mounting member26, the node mounting member26being constructed to mount the steel structure node50. More information on the reaction frame may be found in the later description.

The steel structure node50refers to a planar node or a spatial node in other forms. For example only, as shown inFIG.4, the steel structure node50may include a planar node such as a K-type or a spatial node such as a TT-type or a KK-type.

In some embodiments, the tree-shaped spatial node30may be the steel structure node50when the main pipe31is set parallel to the raft foundation10and the branch pipe32does not contact the raft foundation10.

The node mounting member26may be a structural member for mounting the steel structure node50. In some embodiments, the node mounting member26may include a lower plate261, an upper plate262, and a connection bolt263, as illustrated inFIG.5.

The lower plate261and the upper plate262refer to a structure to secure the main pipe51of the steel structure node50. The upper plate262may be located directly above the lower plate261, which is fixedly connected to the second flange33. More information on the second flange can be found in a later description.

In some embodiments, both the lower plate261and the upper plate262may be provided with a curved surface that is adapted to an outer contour of the main pipe51of the steel structure node50, so as to accommodate main pipes51of different diameters of the steel structure node50while better securing the main pipe51of the steel structure node50. Understandably, when the main pipe51of the steel structure node50is a square pipe, the lower plate261and the upper plate262may be provided with a concave groove, accordingly.

The connection bolt263refers to an element for connecting the lower plate261to the upper plate262. In some embodiments, the node mount member26may include at least four connection bolts263. The at least four connection bolts263may fit one by one with at least four threaded holes disposed on a left side and a right side of the lower plate261and the upper plate262, respectively, to realize a fixed connection between the lower plate261and the upper plate262.

In actual use, for example, when the steel structure node50is a K-type planar node or a TT-type spatial node as shown inFIG.4, the main pipe51of the steel structure node50may be secured to the raft foundation10by using two node mounting members26. For example only, two second flanges33may be provided on the raft foundation10, lower plates261of the two node mounting members26may be fixedly connected to the two second flanges33, respectively, and two ends of the main pipe51of the steel structure node50may be arranged between the lower plate261and the upper plate262of each of the two node mounting members26, respectively, and the main pipe51may be fixed to the raft foundation10by tightening the connection bolt263.

In some embodiments, when the tree-shaped spatial node30is the steel structure node50, an auxiliary positioning frame24may be replaced with the node mounting member26to expand the application of a test method, for example, it may be extended to test planar nodes or spatial nodes of K-type, TT-type, KK-type, etc.

The raft foundation10may be a form of building foundation used to carry building loads and form a raft base. In some embodiments, the raft foundation10may be a reinforced concrete structure including two main beams and a secondary beam, the two main beams being arranged at two ends of the secondary beam to form an H-type beam structure. The H-type beam structure may be capable of reducing a volume of the reinforced concrete structure while meeting a test strength requirement, avoiding using large volume and deep foundations.

In some embodiments, as shown inFIG.2andFIG.7, a reinforcement structure in the raft foundation10may include a main beam reinforcement cage11, a secondary beam reinforcement cage12, and a J-type column base anchor bolt13. A structure of the main beam reinforcement cage11and the secondary beam reinforcement cage12may be the same as a conventional reinforcement cage structure, in which a plurality of sets of ring bars are surrounded outside a plurality of transversely-placed longitudinal bars, and in turn forms a transversely-placed rectangular reinforcement cage.

In some embodiments, the raft foundation10may include two sets of main beam reinforcement cages11and a secondary beam reinforcement cage12, and the two sets of main beam reinforcement cages11may be arranged at two ends of the secondary beam reinforcement cage12, which in turn form an H-type reinforcement cage structure.

In some embodiments, a total of five sets of J-type column base anchor bolts13may be used in the raft foundation10, four sets of which may be used to secure four columns22of the reaction frame20, and a remaining set of which may be used to secure the main pipe31of the tree-shaped spatial node30.

In some embodiments, for the J-type column base anchor bolt13for securing the column22, each J-type column base anchor bolt13may be installed at an end of the main beam reinforcement cage11and may be connected to the main beam reinforcement cage11by a conventional cage preparation manner. In some embodiments, the J-type column base anchor bolt13may include a plurality of J-type anchor hooks131, as shown inFIG.7andFIG.8. Each anchor hook131within the same J-type column base anchor bolt13may be arranged sequentially and uniformly around an axis of a first flange221in the reaction frame20to form a cylindrical reinforcement cage structure. And each anchor hook131in the reinforcement cage structure and a bottom bar of the main beam reinforcement cage11may be screwed together with each other using wires, so as to secure the J-type column base anchor bolt13to an end portion of the main beam reinforcement cage11, thereby realizing the positioning and compression transmission of the reaction frame20.

By connecting the reaction frame20and the raft foundation10as a whole by means of the J-type column base anchor bolt13, the reaction frame20can accurately transfer a tension force to the main beam during testing to cause an upward tendency at two ends of the main beam, which in turn enables the main beam to generate a corresponding upward bending moment.

In some embodiments, for the J-type column base anchor bolt13for securing the tree-shaped spatial node30, the J-type column base anchor bolt13may be mounted in the middle of the secondary beam reinforcement cage12, which is also connected to the secondary beam reinforcement cage12by a conventional reinforcement cage preparation manner. In some embodiments, each anchor hook131within the J-type column base anchor bolt13may be disposed sequentially and uniformly around an axis of the second flange33in the tree-shaped spatial node30. The each anchor hook131in the J-type column base anchor bolt13and a bottom bar of the secondary beam reinforcement cage12may be screwed to each other using wires, to secure the J-type column base anchor bolt13to an end portion of the secondary beam reinforcement cage12.

In some embodiments, as shown inFIG.8, the anchor hook131of a J-type may include two portions: a straight section and a bent section, with the bent section being attached to a bottom of the straight section, which in turn constitutes an integrally molded J-type anchor hook131that may be formed by bending a steel bar. The anchor hook131may be provided with external threads on a top outer circumference to form a threaded section. The bent section at a bottom of the anchor hook131may be bent inwardly and hooked to the bottom bar of the main beam reinforcement cage11or the bottom bar of the secondary beam reinforcement cage12from bottom to up, to increase the pull-out resistance of the anchor hook131.

In some embodiments, a process of constructing the raft foundation10may include excavating a pit according to the design, then erecting a brick mold in the pit, and then dimensions of each reinforcement cage in the raft foundation10are adjusted according to a dimension of the reaction frame20and a dimension of the tree-shaped spatial node30. The individual reinforcing cages are prepared in the brick mold, and then concrete slurry may be poured into the brick mold and the concrete slurry may be covered to submerge the reinforcing cages, and then the concrete slurry may be waited to solidify, and then the construction of the raft foundation10may be completed. The brick mold may be free of dismantling to avoid excavating a larger pit, which reduces the intensity of work and the cost of testing.

An upper end surface of the raft foundation10may need to be treated by the construction process after the concrete is poured so that an upper slab surface of the raft foundation10is a horizontal plane. This ensures that both the tree-shaped spatial node30and the reaction frame20mounted on the raft foundation10may meet the flatness requirement, and a direction of the combined force on the main pipe31may be distributed along a vertical direction. The construction process refers to determining specific construction manners and steps for each construction process according to the construction requirements. Exemplary construction processes may include mortar application, leveling, and compaction, or the like. In some embodiments, the vertical direction may be represented by an X-direction indicated by an arrow inFIG.3.

Before pouring the concrete slurry, it may be necessary to preset a protrusion length of a tip of the anchor hook131in advance so that after the concrete slurry sets, an exposed length of the tip of the anchor hook131may meet the requirements for securing the first flange221and the second flange33.

The reaction frame20may be used to support a building structure or other frame structure. In some embodiments, the reaction frame20may be a hollow hexahedral frame made of a plurality of beams that are connected to each other in sequence, with each beam constituting a corresponding side of the hexahedral frame. Four intersections located on a same plane may constitute support points between the reaction frame20and the ground. The first flange221may be fastened at the support point, and the reaction frame20may be secured to the raft foundation10through the connection between the anchor hook131pre-buried in the raft foundation10to the first flange221for a next test operation.

In some embodiments, the reaction frame20may be designed in a variety of shapes. For illustrative purposes only, as shown inFIG.6, the reaction frame20may be a hollow four-pronged frame with a small top and a large bottom, and a bottom surface of the four-pronged frame may be rectangular, a top surface of the four-pronged frame may be trapezoidal, and the top surface may be arranged at an angle toward a top edge of the trapezoid.

Four beams on the top surface of the four-pronged frame may be referred to as crossbeams21, and four beams on the sides of the four-pronged frame may be referred to as columns22, and four beams on the bottom surface of the four-pronged frame may be referred to as tie beams23. In some embodiments, whether to install the tie beam23depends on the actual situation.

In some embodiments, the crossbeams21and the columns22at four corners of the top surface of the four-pronged frame may be fixedly connected to each other by ball nodes25(as shown inFIG.11). Ends of the tie beams23at four corners of the bottom surface of the four-pronged frame may be fixedly connected to a body of the columns22, and a bottom end of the column22may extend downwardly along an axis of the column22for a short length. The bottom end of the column22may be horizontally notched, and at the bottom end of the column22, a horizontally arranged first flange221may be fixedly mounted concentrically through welding, to facilitate securing the reaction frame20to the raft foundation10through the first flange221.

In some embodiments, the auxiliary positioning frame24of an X-type may be arranged within the reaction frame20, with each of the four ends of the auxiliary positioning frame24being secured to each of the four intersections at the bottom surface of the reaction frame20.

The auxiliary positioning frame24may be a structural member for providing auxiliary positioning for the main pipe31of the tree-shaped spatial node30. In some embodiments, the auxiliary positioning frame24may include a locking sleeve242that may be socketed onto the body of the main pipe31of the tree-shaped spatial node30. Four positioning beams241may be arranged on an outer wall of the locking sleeve242in sequence along a circumference of the locking sleeve242. One end of the positioning beam241may be fixed to an adjacent intersection on the bottom surface, thereby locking the main pipe31of the tree-shaped spatial node30within the bottom surface and avoiding the main pipe31from moving horizontally to eliminate the effect of shear stress on the main pipe31.

After the raft foundation10has been set up, the reaction frame20may be first lifted to a mounting position on an upper end surface of the raft foundation10arranged horizontally, a through-hole on the first flange221in the reaction frame20may be aligned with a top end of the anchor hook131, and the threaded section at the top end of the anchor hook131may be inserted into the through-hole, then a fastening nut may be tightened on the anchor hook131to stably fix the reaction frame20on the raft foundation10.

When the fixing of the reaction frame20is completed, installation of the tree-shaped spatial node30may begin. First, the second flange33may be mounted on a corresponding anchor bolt, then the main pipe31of the tree-shaped spatial node30may be coaxially passed through the locking sleeve242, so that a bottom end of the main pipe31may be coaxially pressed against an upper disk surface of the second flange33and the bottom end of the main pipe31and the second flange33may be welded to each other, and then the second flange33may be fixed to the raft foundation10through a fastening nut. At this time, an axis of the locking sleeve242, an axis of the cylindrical reinforcement cage and an axis of a positioning ring, and an axis of the main pipe31may be all arranged coaxially. When choosing the locking sleeve242, a diameter of the chosen locking sleeve242may need to match with the diameter of the main pipe31. In this way, when the branch pipe32may be socketed within the locking sleeve242, an outer wall of the main pipe31and an inner wall of the locking sleeve242may be closely adhered to each other, thus preventing the main pipe31from moving horizontally. Therefore, when the tree-shaped spatial node30is subjected to horizontal force, the tip of the anchor hook131can avoid shearing due to horizontal displacement, thereby enhancing the safety of the test process.

After the tree-shaped spatial node30is installed, the tree-shaped spatial node30may be located in a space within the reaction frame20, at which point a force measurement assembly for providing a test force may be installed between each branch pipe32and the reaction frame20.

FIG.9is a schematic diagram illustrating an exemplary structure of a pressure assembly according to some embodiments of the present disclosure;FIG.10is a schematic diagram illustrating an exemplary structure of a tension assembly according to some embodiments of the present disclosure; andFIG.11is a schematic diagram illustrating an exemplary structure of a pressure assembly installed at a ball node according to some embodiments of the present disclosure.

A force measurement assembly40refers to an assembly configured to measure a stress applied to the branch pipe32. In some embodiments, as shown inFIG.9andFIG.10, the force measurement assembly40may include two types: a tension assembly41and a pressure assembly42. The tension assembly41may be used to provide a tension to the branch pipe32. The pressure assembly42may be used to provide a pressure to the branch pipe32.

In some embodiments, as shown inFIG.9andFIG.11, the pressure assembly42may include a positioning rod401whose front end may be coaxially inserted into a straight rod, and a disk-shaped head plate402may be coaxially connected to a tail end of the positioning rod401in a fixation manner. The head plate402may be pressed against a pipe end of the branch pipe32to prevent the positioning rod401from further protruding into the branch pipe32. A shape of the head plate402may be not limited, and in addition to being designed in the form of a disk, it may also be designed in the form of a rectangle, or the like.

In some embodiments, the pressure assembly42may further include a positioning sleeve405that is coaxially socketed to the crossbeam21or the column22of the reaction frame20, as illustrated inFIG.9.

The positioning sleeve405may be a structural member of the force measurement assembly40configured to secure the reaction frame20. In some embodiments, an inner diameter of the positioning sleeve405may be slightly larger than a diameter of a corresponding crossbeam21or a diameter of a corresponding column22. With such setup, when the positioning sleeve405is socketed to the crossbeam21or the column22, the positioning sleeve405may rotate around the axis of the crossbeam21or the column22, and may slide back and forth along an axial direction of the crossbeam21or the column22to adjust a position of the positioning sleeve405, thereby facilitating accurate force measurement.

In some embodiments, as shown inFIG.9, the pressure assembly42may further include a pressure telescopic rod421, with a telescopic direction of the pressure telescopic rod421and an axial direction of a corresponding branch pipe32coinciding with each other. A fixation end of the pressure telescopic rod421may be fixedly connected to the positioning sleeve405. A telescopic end of the pressure telescopic rod421may be plumb-fastened to a disk surface of the head plate402, and a load sensor404(this load sensor is noted as a first load sensor) may be pressed and arranged between the telescopic end and the disk surface of the head plate402. The load sensor404may be used to measure pressure exerted by the pressure telescopic rod421on the head plate402. Exemplary load sensors404may include a strain load sensor, a pressure load sensor, or the like.

In some embodiments, the pressure telescopic rod421may employ a jacking jack. In some embodiments, the pressure telescopic rod421may also employ any other feasible structure or device, which is not limited by the present disclosure.

In some embodiments, a plurality of positioning screw holes4051may be provided on the positioning sleeve405along a circumferential direction of the positioning sleeve405for the process of applying force by the pressure telescopic rod421(e.g., a jacking jack) to be in a relatively stable condition. When the positioning sleeve405is rotated and slid to a corresponding position, a threaded connection may be formed between the positioning screw hole4051and a positioning bolt4052, and a front end of the positioning bolt4052may be pressed against the body of the crossbeam21or the body of an inclined column, which then locks the positioning sleeve405to the crossbeam21or the column22. When the positioning sleeve405is fixed, the positioning rod401may be inserted into a corresponding branch pipe32, and then the pressure telescopic rod421and the load sensor404(i.e., the first load sensor) may be installed between the positioning sleeve405and the head plate402, and the telescopic direction of the pressure telescopic rod421and an axial direction of a corresponding branch pipe32may be made to be coincident with each other, and at this time, a positioning plate406whose slab surface may be parallel to a disk surface of a corresponding head plate402, and then the fixation end of the pressure telescopic rod421may be fixedly connected to the slab surface of the positioning plate406, and at this time, the telescopic direction of the pressure telescopic rod421may be plumb to the slab surface of the positioning plate406.

In actual use, due to varying lengths of branch pipes32on the tree-shaped spatial node30, when a distance between a certain branch pipe32and a corresponding positioning plate406is greater than an expansion and contraction limit of the pressure telescopic rod421, it is necessary to fixedly clamp a rectangular connection base403between the load sensor404(i.e., the first load sensor) and the head plate402, and the connection base403is fixed on the head plate402through welding, or the like, and thus the distance between the branch pipe32and the corresponding positioning plate406may be reduced. The distance may be reduced to be within the expansion and contraction limit of the pressure telescopic rod421to allow the pressure telescopic rod421to apply pressure to the branch pipe32and to measure the pressure using the load sensor404(i.e., the first load sensor).

In some embodiments, the tension assembly41may also include a positioning rod401whose front end may coaxially insert into the straight rod. A disk-shaped head plate402may be coaxially secured to a tail end of the positioning rod401. The head plate402may press against a pipe end of the branch pipe32to prevent the positioning rod401from further protruding into the branch pipe. The head plate402may need to be welded to a rod opening of the branch pipe32when testing tension. A connection base403may be welded on an outer disk surface of the head plate402, and a through-hole may be provided on an end surface of the connection base403away from the head plate402. A steel stranded rope411may be threaded through the through-hole, and a front end of the steel stranded rope411, after passing through the through-hole, may pass through a position-limiting plate413disposed within the connection base403again. A locking buckle414may be installed at the front end of the steel stranded rope411to prevent the steel stranded rope411from pulling out of the position-limiting plate413, thereby enabling the steel stranded rope411to be pulled tightly against the connection base403along the axial direction of the branch pipe32, and an axis of the steel stranded rope411after straightening and the axis of the branch pipe32may coincide with each other.

In some embodiments, the tension assembly41may further include a positioning sleeve405that is coaxially socketed to the crossbeam21or the column22of the reaction frame20. An inner diameter of the positioning sleeve405may be slightly larger than a diameter of a corresponding crossbeam21or a diameter of a corresponding column22. With such setup, when the positioning sleeve405may be socketed to the crossbeam21or the column22, the positioning sleeve405may rotate around an axis of the crossbeam21or the column22and may slide back and forth along an axial direction of the crossbeam21or the column22, so as to adjust a position of the positioning sleeve405, thereby facilitating accurate force measurement.

In some embodiments, the tension assembly41may further include a penetrating telescopic rod412, with a telescopic direction of the penetrating telescopic rod412coinciding with an axial direction of a corresponding branch pipe32. A fixation end of the penetrating telescopic rod412may be fixedly connected to the positioning plate406on the positioning sleeve405, and the positioning plate406and the positioning sleeve405in the tension assembly41may be connected in the same manner as that of the pressure assembly42.

In some embodiments, the penetrating telescopic rod412may employ a piercing jack. In some embodiments, the penetrating telescopic rod412may also employ any other feasible structure or device, which is not limited by the present disclosure.

After the positioning sleeve405is installed, a tail end of the steel stranded rope411may be sequentially threaded through the positioning sleeve405and the fixation end of the penetrating telescopic rod412(e.g., the penetrating jack) along an axis of the penetrating telescopic rod412until a telescopic end of the penetrating telescopic rod412. A position-limiting plate413and a locking buckle414may be mounted in the same manner at the tail end of the steel stranded rope411, which in turn can transmit a tension to the branch pipe through the steel stranded rope411that is extended along the axis of the branch pipe32when the penetrating telescopic rod412is elongated.

In actual use, the tension exerted by the penetrating telescopic rod412on the branch pipe32may be tested by clamping and mounting a load sensor404(this load sensor is noted as a second load sensor) between the fixation end of the penetrating telescopic rod412and the connection base403.

In some embodiments, the locking buckle414may employ an annular sleeve tube, when socketed to the steel stranded rope411, the locking buckle414may be deformed by an external force, and thereby wrapping and locking an end of the steel stranded rope411to prevent the steel stranded rope411from moving.

In the process of installing the penetrating telescopic rod412and the pressure telescopic rod421, they may be installed in a manner described above or the rods may be installed by rotating 180 degrees in the manner described above. An installation manner of rotating 180 degrees may enable bottoms of the penetrating telescopic rod412and the pressure telescopic rod421to be fixed directly to the pipe end of the branch pipe32, and then, through the penetrating telescopic rod412and the pressure telescopic rod421, the position of the positioning sleeve405may be determined, and ultimately the other end of the penetrating telescopic rod412and the pressure telescopic rod421may be secured to the reaction frame20to complete the test.

Also, when installing the load sensor404(e.g., the second load sensor and the first load sensor), a small cylindrical projection at a front end of the penetrating telescopic rod412and the pressure telescopic rod421may allow the front end of the penetrating telescopic rod412and the pressure telescopic rod421to form an axial shoulder structure. When fixing the load sensor404, the load sensor404may be directly socketed onto the shoulder structure, and then the load sensor404may be pressed against the positioning plate406or the head plate402. The shoulder structure may be capable of effectively positioning the load sensor404, preventing the load sensor from moving404during the test, and accurately detecting a force on each branch pipe32.

When an extension angle of the branch pipe32is more appropriate, a telescopic rod may be installed using the positioning sleeve405and the positioning plate406. But when the axis of the branch pipe32passes through an intersection on a top surface of the reaction frame20, it is not suitable to use the positioning sleeve405, and at this time, the positioning plate406may be welded directly on the outside or inside of the intersection to install the telescopic rod.

The raft foundation10, the reaction frame20, the tree-shaped spatial node30, and the force measurement assembly40may be sequentially assembled and connected together by the above-described structural composition, and then each tension assembly41or pressure assembly42may be driven to apply a force to each branch pipe32in a set manner.

In some embodiments, the auxiliary positioning frame24can eliminate the effect of a combined force on the main pipe31along a horizontal direction. When the combined force subjected by the main pipe31along a plumb direction is pressure along a plumb downward direction, when gravity is ignored, and at that point, four columns22of the reaction frame20are subjected to a tension force downwardly along the plumb direction. This may achieve a force balance for a whole structure made of the reaction frame20, the force measurement assembly40, and the tree-shaped spatial node30. When the combined force subjected by the main pipe31along the plumb direction is tension along a plumb upward direction, when the effect of gravity is ignored, the four columns22of the reaction frame20are subjected to a thrust upwardly along the plumb direction. This may realize a force balance for the whole structure made of the reaction frame20, the force measurement assembly40, and the tree-shaped spatial node30.

Some embodiments of the present disclosure also use a general-purpose finite element software ABAQUS to perform a finite element analysis of a force performance of a cast steel node of a sports stadium project under a test load, and utilize a reaction frame device provided in some embodiments of the present disclosure to perform a load test for verification.

A concrete plane of the stadium is elliptical, with a length of about 236 m along a north-south direction and a width of about 209 m along an east-west direction. The upper canopy of the stadium adopts a steel truss structure system, and the steel roof adopts a metal roof. An upper canopy of the stadium adopts a steel truss structure system, and a steel roof adopts a metal roof. An upper steel structure is supported by a lower concrete structure with inner and outer ring supports, and a bottom node support column is a steel bone concrete column. This results in a convergence of node rods at supports, with 5 rods converging at an outer ring support and 6 rods converging at an inner ring support. The design needs to follow the “strong nodes, weak components” principle, give full play to the strength of the rod material, the node does not precede the destruction of components, and nodes need to be analyzed for stress.

FIG.12is a schematic diagram illustrating an exemplary 1:2 scaled model of a cast steel node according to some embodiments of the present disclosure; andFIG.13is a mesh delineation diagram for a loading test of a 1:2 scaled model of a cast steel node according to some embodiments of the present disclosure.

As shown inFIG.12andFIG.13, a representative tree-shaped spatial node30structure is selected for force analysis: a diameter of the main pipe31is 800 mm with a wall thickness of 50 mm, and there is no stiffener rib inside, and a cross-section of the main pipe31is 6. A cross-sectional dimension (diameter×wall thickness) of each branch pipe32is: a cross-section 1 (480×40), a cross-section 2 (245×25), a cross-section 3 (402×40), a cross-section 4 (180×20) and a cross-section 5 (480×40).

I. Finite Element Simulation:

A material of the tree-shaped spatial node30is referred to a set standard, and its mechanical property indexes are yield strength of 230 MPa, ultimate strength of 450 MPa, and elongation of 22%. According to data provided by a manufacturer of cast steel, the material's modulus of elasticity is 2.06×105MPa, Poisson's ratio is 0.3, and the yield strength is 230 MPa.

Reference points are established at a position of a centroid of each branch pipe32and coupling constraints with each cross-section are established. The boundary is based on the actual engineering situation, and a bottom of the cross-section of the tree-shaped spatial node30is used as a fixed constraint. Other pipe ends are used as rigid regions, and a local coordinate system is established at a centroid of the rigid region and a concentrated load is applied.

Since a bending moment shear is much smaller than an axial force, a force situation is simplified and the effect of bending moment and shear forces on the nodes is ignored. The system of units used in the analysis is the International System of Units (SI), with the unit of force: N, unit of length: m, and unit of stress in Pa. The tree-shaped spatial node30loads are mainly based on the overall structural calculation of the various working conditions, from which the most unfavorable working conditions of the internal force of the rod are selected and obtained. Loads at each node are derived as shown in table 1 below:

TABLE 1Axial force (kN) at tree-shaped spatial nodes at amost unfavorable working conditionLoadingsurface12345Working364.68675.56608.58138.87255.92conditionIWorking−581.2−831.4−618.7−225.5−306.5conditionII

A VONMISES stress distribution of the tree-shaped spatial node30under a most unfavorable load in Table 1 is obtained, and the stress distribution of the node has following patterns:(1) Portions with a large stress are concentrated on a branch pipe No. 2 with a large load at a rod end, and a stress magnitude is around 50 MPa, while stress values of rod ends of the rest of the branches are relatively small, and a stress magnitude is around 20 MPa.(2) The maximum stress value of the node is 83.8 MPa, which occurs at the intersection between the branch pipe No. 2 and the ball node. The peak stress does not exceed the yield strength of the material, and stresses in all regions of the node are within the elastic range, and stresses of most of the regions of the node are within 100 MPa, and it can be deduced that the node is subjected to a load much smaller than its bearing capacity.

In order to make the test loading tonnage and member size as close as possible to the limit loading capacity of the designed loading device and to meet the test accuracy and other requirements, it was decided to use a 1:2 scaled-down ratio for the test.

Under the condition of 1:2 scaling ratio, the similarity ratio of internal force is 1:4, and the corresponding internal force after scaling is shown in Table 2 below. At the same time, the safe surplus of bearing capacity after exceeding the design load should be considered, and a space for the later loading needs to be reserved, so the similarity ratio of 1:2 size is chosen.

TABLE 2Axial forces (kN) of the tree-shaped spatial nodes after1:2 scaling-down at a most unfavorable working conditionLoading surface123456Working−87.6−187.7−156.5−378.1−337.2−347.4condition IWorking−40.6−151.9−63.5−621.7−507.4−451.7condition II

A VONMISES stress distribution of the tree-shaped spatial node30under a most unfavorable load in Table 2 is obtained, it can be seen that:(1) Portions with a large stress are concentrated on the branch pipe No. 2 with a large load at a rod end, and the stress magnitude is around 50 MPa, while the rest of the rod ends have relatively small stress values, and the stress magnitude is around 20 MPa.(2) A maximum stress value of 138 MPa at the node occurs at a base. Since a partial of stresses concentrates due to the scaling down, the peak stress does not exceed the yield strength of the material, the stress in all areas of the node is within the elastic range, and most of the areas of the node are within 100 MPa, and it can be inferred that the node is subjected to a load much smaller than its bearing capacity.
II. Loading Test Verification:

The 1:2 scaled model is placed in this reaction frame device, a pressure test member is connected to a tension test member according to a force corresponding to the tree-shaped spatial node30, and each connected node with the test load as shown in Table 3 and Table 4 below (tension is positive, pressure is negative).

TABLE 3Axial forces (kN) of the nodes after 1:2 scaling downunder a most unfavorable working conditionLoadingsurface12345Working−145.3−207.8−154.7−56.4−76.6condition IWorking91.2168.9152.234.763.9condition II

TABLE 41.3 times the axial force (kN) of the nodes after 1:2scaling down under a most unfavorable conditionLoadingsurface12345Working−188.89−270.14−201.11−73.32−99.58condition IWorking118.56219.57197.8645.1183.07condition II

The test adopts graded loading with a total of 10 levels for loading, before reaching the design load, the loading amount of each level is 15% of the design load, loaded from 0 to 1.3 times the design load, please refer to Table 5. A loading sequence is as follows:1. Pre-loading: 50% of the design load is applied, loaded in three stages, and then unloaded for checking and testing the connection and working status of each related equipment in preparation for formal loading.2. Formal loading stage: the load step is taken as 15% of the design load, and load is performed step by step until 90% of the design load, then the load step is adjusted to 10% to load step by step to 130% of the design load. After applying each level of load, pausing for 3 minutes, the data is read after the various responses are stabilized, and then it is continued to apply the next level of load.3. Uninstallation stage: the entire uninstallation condition is also divided into 10 levels to mainly observe the change of data, and after the uninstallation is completed finally, carefully compare whether the strain after the uninstallation is recovered.

TABLE 5Loading regime table of working conditions at nodes (unit: kN)DesignLoadloadBranchBranchBranchBranchBranchRatingtimespipe 1pipe 2pipe 3pipe 4pipe 5115%13.6825.33522.835.2059.585230%27.3650.6745.6610.4119.17345%41.0476.00568.4915.61528.755460%54.72101.3491.3220.8238.34575%68.4126.675114.1526.02547.925690%82.08152.01136.9831.2357.517100%91.2168.9152.234.763.98110%100.32185.79167.4238.1770.299120%109.44202.68182.6441.6476.6810130%118.56219.57197.8645.1183.07

In view of the fact that each branch pipe32is only axially stressed and the form of stress is simple, it is contemplated that a unidirectional strain gauge along the axial direction of the branch pipe32is arranged at the rod end of the tree-shaped spatial node30. And a node region, i.e., an intersection region of the branch pipe32and the branch pipe32, due to the complexity of the force thereof, it is not possible to determine the direction of the principal stress of the coherent accessory branch pipe32, and for this reason, a 45° three-way strain gauge is arranged in the coherent accessory of the branch pipe32in order to examine the stress distribution here.

Based on the strain and the hydraulic jack loading indications obtained by the load sensor and a strain collector, the stress at the corresponding position of the tree-shaped spatial node30and the end load value of the branch pipe32may be calculated, respectively. The strain at a corresponding position of the unidirectional strain gage may be calculated using a following formula:
σ=Eε;Where, σ denotes stress, E denotes elastic modulus, and ¿ denotes Poisson's ratio.

The stress at a symmetric position may be calculated using a following formula:

σs=σ12+σ32+(σ1+σ2)22;

Where, σs denotes the stress at the symmetric position, σ1denotes stress of a branch pipe No. 1; σ2denotes stress of a branch pipe No. 2; σ3denotes stress of a branch pipe No. 3; and a strain value at the symmetric position of the same branch pipe32are averaged, where the elastic modulus E is taken from the material test results, and the Poisson's ratio ε is taken as 0.3. Tree-shaped spatial node30in the No. 2 branch pipe and the No. 3 branch pipe is relatively large, so the results of the corresponding strain curve of the measurement point are given, as well as the corresponding working conditions of the larger force of the rod cast steel section strain and strain conversion stress comparison.

From the results of the experimental test, it can be seen that, except for some branch pipes, each branch pipe basically changes linearly during the loading process. This indicates that when loaded according to 1.3 times the design load, the tree-shaped spatial node30has been in the state of elastic deformation, and has not reached the yield stress. The change rule of the strain of the tree-shaped spatial node30under the two working conditions is basically the same, indicating that there is little difference in the tension and pressure mechanical properties of the cast steel specimens. During the loading process of the whole tree-shaped spatial node30, a strain of the No. 2 branch pipe in the branch pipe is the largest, reached 269με, its stress is about 56 MPa; a local stress occurred at an intersection between the main pipe31of the No. 2 branch pipe and the No. 6 branch pipe is the largest, reaching 104 MPa, which is lower than the yield stress of steel 365 MPa, with a margin of 2.5, indicating that the specimen is reasonably designed. The position is the chamfered area where the No. 2 branch pipe32meets a No. 6 main pipe31of the tree-shaped spatial node30. On one hand, the second branch pipe32is the component under the greatest stress. On the other hand, this area is where the branch pipes converge, resulting in a complex stress state and a tendency for stress concentration. In both conditions, the measurement points for ZG2-5 and ZG3-5 are in the middle area of branch pipe32, and compared to the other four points located at the ends of branch pipe32, strain values thereof are smaller. This may be because stress concentration occurs at the pipe ends, and as stress is transferred to the middle area of branch pipe32, the strain approaches the true strain value under the current conditions, resulting in smaller values.

The results of the finite element analysis show that the tree-shaped spatial node30is designed to have high safety redundancy, but in view of the error between the modeling and the actual significance, it is tested to prove the performance of the tree-shaped spatial node30. The test results show that the tension and pressure mechanical properties of the tree-shaped space node30are similar to the results of the finite element simulation, with an error of 10% or less, and the results can be mutually verified.

The foregoing tests demonstrate that the reaction frame device provided by some embodiments of the present disclosure is capable of being used for testing of tree-shaped spatial nodes in existing engineering. This reaction frame device has a simple structure, is easy to use, and can partially replace finite element simulation work, which greatly simplifies the process of testing of tree-shaped spatial nodes in existing engineering, and provides test results consistent with the theoretical simulation as reliable references for engineering.

In some embodiments, a reaction frame device may further include a control system (not shown in the figures), and the control system may be configured to control each tension assembly41or each pressure assembly42to apply force to each branch pipe based on a preset loading test. In some embodiments, the control system may be further configured to control both the tension assembly41and the pressure assembly42to apply force to each branch pipe32simultaneously based on a preset loading test.

The control system may be a system used to control other parts or components of the reaction frame device. In some embodiments, the control system may be used to control the force measurement assembly40(e.g., the tension assembly41and the pressure assembly42).

In some embodiments, the force measurement assembly40may include an electric jack, i.e., the penetrating telescopic rod412of the tension assembly41and the pressure telescopic rod421of the pressure assembly42both employ electric jacks. The control system may be communicatively connected to a drive module of the electric jack and control the force measurement assembly40in real-time based on a preset loading test. Exemplary communication connections may include Bluetooth, WIFI, fiber optics, etc.

The preset loading test refers to a preset loading test verification manner. For more information on loading test verification, please refer to the previous description.

In some embodiments, the reaction frame device may further include a processor (not shown in the figures), the processor being configured to determine whether to generate inspection strategy information based on strain data, load data, and control data during a preload test.

The processor may process data and/or information obtained from other devices or systems. The processor may execute program instructions based on such data, information, and/or processing structures to perform one or more of the functions described in the present disclosure. In some embodiments, the processor may include one or more sub-processing devices (e.g., a single-core processing device or a multi-core processing device). By way of example only, the processor may include a central processing unit (CPU), a controller, a microprocessor, etc., or any combination of the above.

The preset loading test may be a testing phase before a formal loading test. For more information on the preset loading, please refer to the previous description.

The strain data refers to deformation data of a strain gauge (e.g., a unidirectional strain gauge, etc.). In some embodiments, the strain data may be used to characterize stress at a corresponding position of the strain gauge.

In some embodiments, the processor may be communicatively connected to the strain gauge to obtain the strain data through the strain gauge.

The load data may be relevant data measured by a load sensor (e.g., the first load sensor, etc.). In some embodiments, the load data may include at least one of first load data or second load data. In some embodiments, the load data may be used to characterize force applied axially to the branch pipe32.

In some embodiments, the processor may be communicatively coupled to the load sensor to obtain the load data via the load sensor.

The control data is data related to the control system used to control the force measurement assembly40. For example, the control data may include a distance moved by the tension assembly41and/or the pressure assembly42(e.g., a distance by which the penetrating telescopic rod412of the tension assembly41and/or the pressure telescopic rod421of the pressure assembly42is extended or shortened), a movement speed, or the like.

In some embodiments, the processor may also be communicatively coupled to the control system to obtain the control data directly from the control system.

The inspection strategy information refers to strategy information related to alerting a technician to inspect issues such as device connectivity or device installation. For example, the inspection strategy information may include the need to re-inspect the installation of the load sensor, etc.

In some embodiments, the processor may determine whether or not to generate the inspection strategy information based on the strain data, the load data, and the control data during a preloading test by determining whether the strain data, the load data, and the control data satisfy a preset condition.

As an example only, when any one of the strain data, the load data, and the control data does not satisfy the preset condition, a corresponding inspection strategy information is generated. The preset condition may be that a difference between the strain data and a preset strain threshold exceeds a strain change range, a difference between the load data and a preset load threshold exceeds a load change range, and a difference between the control data and a preset control threshold exceeds a control change range, and so on. In some embodiments, the preset strain threshold, the strain change range, the preset load threshold, the load change range, and the preset control threshold, and the control change range may be set in advance by a skilled person.

In some embodiments, the processor may, in response to determining the load data satisfying a first preset condition, determine the load sensor as an object to be inspected and generate the inspection strategy information. The inspection strategy information includes that the installation of the load sensor needs to be reinspected.

In some embodiments, the first preset condition may include that a difference between the load data and a reference load data is negative and the load data exceeds a preset range.

The reference load data may be a theoretical value of the load data. In some embodiments, the reference load data may be determined based on a preset comparison table. The preset comparison table may be used to characterize a correlation between the control data and the reference load data, and each control data may have a corresponding reference load data. In some embodiments, the preset comparison table may be constructed based on test data from a historical loading test and an evaluation of the historical loading test by a technician. The evaluation of the historical loading test by the technician may reflect a good result or a bad result of the historical loading test. For example, the more the result of the historical loading test converges to a force situation simulated by a finite element software, the higher the score of the loading test.

In some embodiments, the technician may determine actual load data of a historical loading test with a highest score as the reference load data.

The preset range may be a preset data range that the load data should be in. For example, the preset range may be [0.9×reference load data, 1.05×reference load data], etc.

In some embodiments, the preset range correlates to a distance between two parallel axes. For example, the further the distance between the two parallel axes, the lower the limit of the preset range and the higher the preset range.

The two parallel axes may include a center axis of the positioning plate406, and an axis of the penetrating telescopic rod412or the pressure telescopic rod421that coincides with the axis of the branch pipe32. In some embodiments, the distance between the two parallel axes may be actually measured by a skilled person.

More information on the parallel axes can be found in the relevant descriptions later (e.g.FIG.14).

Understandably, if the distance between the two parallel axes is 0 (i.e., the center axis of the positioning plate406, the axis of the penetrating telescopic rod412or the pressure telescopic rod421that coincides with the axis of the branch pipe32), a force is transferred best at this point and test data obtained is more accurate. On the contrary, if the distance between the two parallel axes is larger, the more inaccurate test data is obtained, so the limit of the preset range may be lower and the preset range may be larger.

The object to be inspected is an object waiting to be inspected. In some embodiments, when the load data satisfies the first preset condition, the processor may directly identify the load sensor as the object to be inspected, and automatically generate the inspection strategy information via code to facilitate reminding the technician to inspect the installation of the load sensor.

In some embodiments, the processor may also, in response to determining that the load data satisfies a second preset condition, determine the force measurement assembly40and the control system as objects to be inspected and generate the inspection strategy information. The inspection strategy information may include there is a need to re-inspect the tension assembly41and/or the tension assembly42, and a need to re-inspect the control system.

In some embodiments, the second preset condition may include that the difference between the load data and the reference load data is positive and the load data exceeds the preset range.

Understandably, if the force measurement assembly40(e.g., the tension assembly41) is moved by a distance, but actually-detected load data is much greater than the reference load data, there may be a malfunction in the force measurement assembly40, or a malfunction in the control system. Therefore, it is necessary to recheck the force measurement assembly40and the control system.

In some embodiments, when the load data satisfies the second preset condition, the processor may determine the force measurement assembly40and the control system as objects to be inspected, and automatically generate the inspection strategy information via code to facilitate reminding the technician to inspect the tension assembly41and/or pressure assembly41, and the control system.

Some embodiments of the present disclosure, by automatically analyzing test result data of the preset loading test at a preloading test stage and giving an analysis result and inspection advice, the technician can re-inspect a connection or a working state of a device, etc., thus helping to ensure the completion of a subsequent formal loading test and the accuracy of test data.

In some embodiments, the control system may control the force measurement assembly40to stop applying force in response to determining the load data satisfies the second preset condition.

In some embodiments, when the load data satisfies the second preset condition, the control system may automatically generate a stop force application command via code and send the stop force application command to the force measurement assembly40to control the force measurement assembly40to stop applying force.

When the load data satisfies the second preset condition (i.e., the load data is much larger than the reference load data), a design load may be too large, and at this time, by controlling the force measurement assembly40to stop applying force through the control system, the damage caused by the design load being too large may be effectively avoided.

In some embodiments, the processor may be further configured to generate the inspection strategy information in response to a stress uniformity of any one of the branch pipes32exceeding a first preset threshold after the control system has controlled the force measurement assembly40to apply force simultaneously. The inspection strategy information may include adjusting the axis of the penetrating telescopic rod412or the pressure telescopic rod421that coincides with the axis of the branch pipe32through an axis adjustment device.

The stress uniformity may reflect a degree of uniformity of stress on the same branch pipe32. In some embodiments, the stress uniformity may be a ratio of a stress difference to a maximum value of stress at a symmetrical position of the branch pipe32for a same branch pipe32.

In some embodiments, the stress uniformity may be calculated. In some embodiments, the technician may number or code the branch pipe32and a unidirectional strain gauge disposed on the branch pipe32to facilitate determining a corresponding stress uniformity of each branch pipe32.

For example, unidirectional strain gauges symmetrically disposed on the branch pipe1may be noted as a unidirectional strain gauge A1and a unidirectional strain gauge A2, and a strain at a position corresponding to the unidirectional strain gauge A1may be σ1and a strain at a position corresponding to the unidirectional strain gauge A2may be σ2. If σ1>σ2, then the strain uniformity of this branch pipe1=|σ1−σ2|/σ1.

For more details on a calculation manner of stress σ at a corresponding position of the unidirectional strain gauge, please refer to the previous description.

In some embodiments, when the control system controls the force measurement assembly40to apply force simultaneously and a stress uniformity of any one of the branch pipes32exceeds the first preset threshold, the processor may automatically generate the inspection strategy information via codes to alert the technician to adjust the axis of the penetrating telescopic rod412or the pressure telescopic rod421that coincides with the axis of the branch pipe32via the axis adjustment device. In some embodiments, the first preset threshold may be set in advance by a technician based on prior experience.

More information on the axial adjustment device can be found in the relevant description later (FIG.14).

In some embodiments of the present disclosure, by analyzing the stress uniformity on each of the branch pipe32and generating the inspection strategy information when the stress uniformity of a certain branch pipe32exceeds the first preset threshold, a technician may be reminded to adjust the axis of the penetrating telescopic rod412or the pressure telescopic rod421that coincides with the axis of the branch pipe32via the axis adjustment device, so as to make the axis parallel or even overlap with a center axis of the positioning plate406, thereby facilitating the transfer of force and ensuring the accuracy of the test data.

In some embodiments, the processor may be further configured to generate the inspection strategy information in response to determining a stress increase uniformity of the branch pipe32exceeds a second preset threshold after the control system has controlled the force measurement assembly40to apply force simultaneously; and, based on the stress increase uniformity and the strain data, determine a target distance between the two parallel axes. The inspection strategy information may include adjusting the axis of the penetrating telescopic rod412or the pressure telescopic rod421that coincides with the axis of the branch pipe32via the axis adjustment device.

The stress increase uniformity may be used to characterize how well a magnitude of stress increase of each branch pipe32matches a corresponding design load increase magnitude during the simultaneous application of force. More information on the design load can be found in the preceding description.

In some embodiments, the processor may obtain the stress increase uniformity of the branch pipe32by calculating an average of differences between strain data and theoretical strain data of each branch pipe32.

As an example only, the processor may calculate theoretical strain data of each branch pipe32based on the load data and a cross-sectional area of each branch pipe using a theoretical stress calculation formula; and calculate an average of differences between strain data and theoretical strain data of each branch pipe32using an average calculation formula, i.e., the stress increase uniformity of the branch pipe32is obtained.

An exemplary theoretical stress calculation formula may include σ′1=F1/A1. where, σ′1denotes theoretical strain data of a branch pipe1; F1denotes load data of the branch pipe1; and A1denotes a cross-sectional area of the branch pipe1. The cross-sectional area of the branch pipe refers to an area of a cross-section of the branch pipe that is plumbed to an axial direction of the branch pipe. In some embodiments, the cross-sectional area of the branch pipe may be obtained by input from the technician, and the load data may be obtained based on the load sensor.

An exemplary average calculation formula may include:

σ¯=(❘"\[LeftBracketingBar]"σ1-σ1′❘"\[RightBracketingBar]"+❘"\[LeftBracketingBar]"σ2-σ2′❘"\[RightBracketingBar]"+…+❘"\[LeftBracketingBar]"σn-σn′❘"\[RightBracketingBar]")n,
where,σdenotes a strain increase uniformity of the branch pipe32; and |σn−σ′n| denotes a difference between strain data and theoretical strain data of an n-th branch pipe32.

In some embodiments, when the stress increase uniformity of the branch pipe32exceeds the second preset threshold after the control system has controlled the force measurement assembly40to apply force simultaneously, the processor may automatically generate the inspection strategy information via codes to alert the technician to adjust the axis of the penetrating telescopic rod412or the pressure telescopic rod421that coincides with the axis of the branch pipe32via the axis adjustment device. In some embodiments, the second preset threshold may be set in advance by the technician.

Understandably, even though design loads applied to different branch pipes32are different, a stress on each branch pipe32should increase linearly after the force is applied simultaneously since each branch pipe32is only subjected to a force axially. That is to say, an increase of a on a design load applied to a particular branch pipe32should theoretically result in an increase of b in a stress on that branch pipe32. If an actual stress increase is less than the theoretical stress increase b, it may indicate that the axis of the penetrating telescopic rod412or the pressure telescopic rod421that coincides with the axis of the branch pipe32is not parallel to or coincides with the center axis of the positioning plate406(i.e., the axis of the penetrating telescopic rod412or the pressure telescopic rod421that coincides with the axis of the branch pipe32is tilted), such that the force along the axial direction of the branch pipe is partially broken up along other directions.

Based on this, by comparing whether or not the stress increase uniformity of the branch pipe32exceeds the second preset threshold, it is equivalent to analyzing an overall stress situation of a plurality of branch pipes32and determining whether an axis of any of the branch pipe32in the plurality of branch pipes32is tilted relative to the axis of the penetrating telescopic rod412or the pressure telescopic rod421. Such analysis manner is closer to the actual situation, which may make the subsequent adjustment of the axis more reliable.

The target distance may be a straight line distance that should be satisfied between the center axis of the positioning plate406and the axis of the penetrating telescopic rod412or the pressure telescopic rod421that coincides with the axis of the branch pipe32in a parallel state.

In some embodiments, the processor may, based on the stress increase uniformity and the strain data, determine a branch pipe32corresponding to a maximum value of a difference between the strain data and the theoretical strain data when the stress increase uniformity exceeds the second preset threshold as an object to be adjusted. The processor may then determine the target distance by calculating a straight line distance between an axis of the object to be adjusted and the center axis of the positioning plate406. The object to be adjusted may be a branch pipe32whose axis needs to be adjusted to be parallel with the center axis of the positioning plate406. Exemplary distance calculation manners may include a translation manner, a vector manner, an iso-volume manner, a constructor manner, or the like.

In some embodiments, the processor may be further configured to generate a drive command based on the target distance between the two parallel axes and send the drive command to a drive component of a motorized axis adjustment device, so that the motorized axis adjustment device may adjust the object to be adjusted based on the target distance between the two parallel axes.

In some embodiments, the processor may be communicatively coupled to the motorized axis adjustment device, such as the drive component. For more information on the motorized axis adjustment device, please refer toFIG.14and its related description.

In some embodiments, the processor may automatically generate the drive command via codes and send the drive command to the drive component of the motorized axis adjustment device based on the target distance between the two parallel axes. The drive command may be a command related to driving the motorized axis adjustment device to adjust the object to be adjusted based on the target distance between the two parallel axes.

In some embodiments, when the drive component of the motorized axis adjustment device receives the drive command, the drive component may immediately control the motorized axis adjustment device to adjust the object to be adjusted based on the target distance between the two parallel axes until a straight line distance between an axis of the object to be adjusted and the center axis of the positioning plate406is the target distance (i.e., the axis of the object to be adjusted and the center axis of the positioning plate406are parallel), and the adjustment is stopped.

In some embodiments of the present disclosure, the object to be adjusted may be automatically adjusted by the motorized axis adjustment device based on the target distance between the two parallel axes, which may conveniently and quickly make the axis of the object to be adjusted parallel to the center axis of the positioning plate406, thereby improving the accuracy of the test data.

FIG.14is a schematic diagram illustrating an exemplary structure of an axis adjustment device according to some embodiments of the present disclosure. As shown inFIG.14, a reaction frame device may further include an axis adjustment device60, the axis adjustment device60including two L-type plates61and two adjustment bolts62.

The axis adjustment device60refers to a device for adjusting a position of the branch pipe32so that an axis of the branch pipe32is parallel or even coincides with a center axis of the positioning plate406.

FIG.14shows the axial adjustment device60in connection with the pressure assembly42. As shown inFIG.14, the two L-type plates61and two adjustment bolts62may be rotationally and symmetrically provided on two sides of fixation ends of the positioning plate406and the pressure telescopic rod421. Inner sides of the two L-type plates61may be affixed to end surfaces of the fixation ends of the positioning plate406and the pressure telescopic rod421, respectively, for snapping the fixation ends of the positioning plate406and the pressure telescopic rod421between the two L-type plates61. The two adjustment bolts62each pass through one of the L-type plates61and are connected to a side end of the positioning plate406and a side end of the fixation end of the pressure telescopic rod421, respectively.

In some embodiments, a position of a center axis of the positioning plate406relative to an axis of the pressure telescopic rod421may be adjusted by adjusting a tightening depth of the adjustment bolt62. Furthermore, since the pressure telescopic rod421and the branch pipe32are coaxially provided, by adjusting the tightening depth of the adjustment bolt62, it may be possible to achieve such that the center axis of the positioning plate406and an axis of the pressure telescopic rod421that coincides with an axis of the branch pipe32are parallel or even coincide.

In some embodiments, the axis adjustment device60may be set up slightly differently between the tension assembly41and the branch pipe32since the tension assembly41and the branch pipe32are connected in a different manner than the pressure assembly42and the branch pipe32. Specifically, since holes are provided at positions through which the steel stranded rope411passes, a diameter of a hole on the positioning plate406may be larger than a diameter of the steel stranded rope411to provide the axial adjustment device60between the positioning plate406and the connection base403.

It should be noted that the axis adjustment device60may also take any other feasible structural form that is capable of making the center axis of the positioning plate406and the axis of the pressure telescopic rod421that coincides with the axis of the branch pipe32parallel or even coincide.

Understandably, when the center axis of the positioning plate406and the axis of the pressure telescopic rod421or the penetrating telescopic rod412that coincides with the axis of the branch pipe32coincide, force may be transferred optimally, and the subsequently obtained test data may be more accurate. However, due to other factors such as manufacturing errors, calculation errors, or the like, after installation, the center axis of the positioning plate406and the axis of the pressure telescopic rod421or the penetrating telescopic rod412that coincides with the axis of the branch pipe32may be misaligned and may not coincide or be parallel. Therefore, by providing the axis adjustment device60, the center axis of the positioning plate406and the axis of the pressure telescopic rod421or the penetrating telescopic rod412that coincides with the axis of the branch pipe32may be made parallel or even overlapped as much as possible, which is conducive to improving the force transfer effect, and thus improving the accuracy and reliability of the test data.

In some embodiments, the axis adjustment device60may be a motorized axis adjustment device that includes at least a drive component and is communicatively coupled to a processor.

The motorized axis adjustment device may be an axis adjustment device60capable of being controlled electrically. The drive component may be a component that drives an operation of the motorized axis adjustment device. Exemplary drive components may include a servo motor, an electric cylinder, or the like.

As an example only, the drive component may be a servo motor, and an output axis of the motor may be connected to the adjustment bolt62, and the tightening depth of the adjustment bolt62may be adjusted by rotating the motor. For example, if the motor is rotated positively, the tightening depth of the adjustment bolt62may be increased; if the motor is rotated negatively, the tightening depth of the adjustment bolt62may be decreased.

In some embodiments, the drive component may, in response to receiving a drive command sent from the processor, control the motorized axis adjustment device to automatically adjust the branch pipe32so that the axis of the branch pipe32is parallel to or even coincides with the center axis of the positioning plate406. For more information on how the motorized axial adjustment device achieves an automatic adjustment, please refer to the related description in the preceding section.

In some embodiments of the present disclosure, through further using the motorized axis adjustment device, an automatic adjustment of an axis is realized, which reduces manual operation and enhances automation in the process of axis adjustment.

Beneficial effects of a test method for measuring a force situation of a tree-shaped spatial node may include, but are not limited to:1. In some embodiments of the present disclosure, due to a large combined force subjected by a tree-shaped spatial node, using a steel reaction frame and a raft foundation to synergistically subject a force, and a steel reaction frame for a test is designed to be an incompletely self-reaction device, which is capable of effectively reducing an amount of steel used in the reaction frame, and at the same time increase the reliability of the reaction frame in the test process.2. In some embodiments of the present disclosure, a pulling force that is vertically upward is applied at four column base positions of the reaction frame and at a column base position at a bottom of a main pipe in the tree-shaped spatial node, so the raft foundation is used to replace an anti-drawing pile foundation and a large independent foundation, and a force at each column base is effectively transferred to the raft foundation by utilizing a main beam and a secondary beam, which makes the overall force distribution of the device more reasonable.3. An anchor hook of a J-type used in some embodiments of the present disclosure, in conjunction with the main beam and the secondary beam, can form a stable stress connection, which in turn ensures the stability of the test process, and at the same time can reduce the use of steel and concrete, reducing the cost of the test.4. In some embodiments of the present disclosure, a positioning beam is provided at the column base of the tree-shaped spatial node and each column base of the reaction frame, which can solve the displacement phenomenon at the column base at the bottom of the main pipe caused by a relatively large horizontal shear force is generated due to differences between force situations and force directions of each branch pipe during the test.5. In some embodiments of the present disclosure, by scaling down the tree-shaped spatial node in proportions, a dimension of a test device may be reduced and a loading tonnage of a force may be reduced.6. The cooperation between a jack, a positioning plate, a head plate, and a positioning sleeve may load two working conditions of pulling and pressing on the tree-shaped spatial node.7. For different test contents, a bifurcation angle of each branch pipe in the tree-shaped spatial node is different, adjacent columns and crossbeams may present different angles through a ball node to meet the demand of multiple bifurcation angles of the branch pipe to complete the test smoothly.8. In some embodiments of the present disclosure, constituting the reaction frame using the cooperation between the crossbeam, the column, and the ball node, for different projects with different bifurcation angles for branches, can provide a frame structure that is easy to adjust and suitable for a test. Since the combined force subjected by the main pipe of the tree-shaped spatial node is larger, using the steel reaction frame with the raft foundation to synthetically subject to force can reduce the amount of steel used and increase reliability.9. Some embodiments of the present disclosure provide the reaction frame device in which a to-be-tested tree-shaped spatial node is placed inside the reaction frame, and a tension assembly or a pressure assembly is arranged on each branch pipe, which can apply force according to a working condition of test pressure or a working condition of test tension based on a loading condition. The working condition of test pressure may be performed using a jack and a load sensor arranged between the reaction frame and the tree-shaped spatial node, and the working condition of the test tension may be performed using a penetrating jack and a steel stranded rope placed outside the reaction frame; and by testing corresponding force application situations in two different ways, the accuracy of force application may be effectively improved. The reaction frame device has a simple structure and is easy to set up, which can greatly simplify the process of testing the tree-shaped spatial node in the existing engineering, and provide a test result in line with the theoretical simulation, which provides a reliable reference for the engineering.10. The auxiliary positioning frame includes a locking sleeve that may be socketed to the body of the main pipe of a tree-shaped spatial node, four positioning beams are arranged sequentially on an outer wall of the locking sleeve along a circumferential direction of the locking sleeve, and one end of the positioning beam is fixedly coupled with an adjacent intersection on a bottom surface in turn, thus locking the main pipe of the tree-shaped spatial node within the bottom surface, which prevents the main pipe from moving horizontally and eliminating the effect of shear stress on the main pipe.11. In some embodiments of the present disclosure, by automatically analyzing test result data of a preset loading test during a preset loading test stage and giving an analysis result and inspection advice, a technician can re-inspect and adjust the connection or working condition, etc., of a device based on the inspection advice, thereby contributing to ensuring the completion of the subsequent formal loading test and the accuracy of the test data.12. In some embodiments of the present disclosure, by setting up an axis adjustment device, a center axis of a positioning plate and an axis of a pressure telescopic rod or a penetrating telescopic rod that coincides with an axis of the branch pipe are parallel or even overlapping as much as possible, which is conducive to increasing the effect of the force transfer, and thus improving the accuracy and reliability of the test data.

The basic concepts have been described above, and it is apparent to those skilled in the art that the foregoing detailed disclosure serves only as an example and does not constitute a limitation of the present disclosure. While not expressly stated herein, a person skilled in the art may make various modifications, improvements, and amendments to the present disclosure. Those types of modifications, improvements, and amendments are suggested in the present disclosure, so those types of modifications, improvements, and amendments remain within the spirit and scope of the exemplary embodiments of the present disclosure.