BLAST-RESISTANT BARRIER

Abstract: An energy absorbing device (30) having a faceplate (31) and a base (32,33) and at least two permanently deformable sidewalls (34,35) extending between and connecting the faceplate (31) to the base (32,33). Each of the sidewalls (34,35) is partially bent along at least one bend line (38) disposed between and extending parallel with the faceplate (31) and the ­ base (32,33). Upon the occurrence of substantial impact upon the faceplate (31), each of the sidewalls (34,35) will perma­ nently deform about the bend line (38) and collapse toward the base (32,33) thereby to absorb the impact energy transmit­ ted. The device (30) is useful in blast-resistant roof and wall structures wherein the device (30) is crushed prior to panel failure. The device (30) can absorb more than 50% of the blast impulse. The present device (30) may also be interposed between a structure and a source of anticipated dynamic impact load. The device (30) will sustain the dynamic impact load from the source by absorption of the impact energy transmitted.

Description: Energy Absorbing Device This invention relates to a device of the type adapted to absorb and dissipate the kinetic energy transmitted by dynamic impact loads. The protection of structures from damage resulting from dynamic impact loads has become increasingly important because of the high cost of repairing the resulting damage. Such protection is provided by a number of different types of energy absorbing devices. In general the type of energy absorbing device to which the present invention is concerned includes one or more expendable elements which are used only once and then are replaced for the next use. In particular, the expendable element comprises a core which absorbs the impact energy by permanent deformation, e.g., wrinklebuckling or crushing of the core walls. It is known that extremely high initial peak loads are required to initiate buckling of the core walls. Once buckling has been initiated, the load (plastic load) required to continue crushing of the core walls is significantly less than the peak load. It is also well known that the structure supporting the energy absorbing device also must be capable of sustaining the high peak load. Consequently, economies in the construction of the supporting structure can be achieved by providing an energy. absorbing device wherein the peak load is approximately equal to the plastic load, i.e., wherein the peak load-to-plastic load ratio approaches unity. Energy absorbing devices having expendable cores are well known in the prior art. Such devices may exhibit (a) a substantially uniform energy absorption rate, see U.S. patent 3,130,819 (MARSHALL); (b) a uniformly increasing energy absorption rate followed by a substantially uniform energy absorption, see U.S. patents 3,552,525 (SCHUDEL) and 3,682,463 (RADIMIRSCH et al); and (c) two or more energy absorption rates of progressively higher value, see U.S. patents 3,806,180 (PATTERSON) and 3,981,114 (CHUPIK), West German patent 1,923,305 (GERTH), and copending application serial number 855,074 (BRICMONT et al) filed November 25, 1977, and assigned to the assignee of this invention. The core of the MARSHALL device is provided with a precrushed end. While the MARSHALL device avoids the high buckle-initiating peak loads when in use, the loads are encountered during manufacture of the core. That manufacturing technique requires the expenditure of large amounts of costly energy. The SCHUDEL and RADIMIRSCH et al devices also avoid the high buckle-initiating peak loads. Both devices incorporate modified honeycomb cores and anvils which are relatively expensive to manufacture. The PATTERSON, CHUPIK, GERTH, and BRICMONT et al devices attempt to minimize the effects of the high buckle-initiating peak loads by providing stepwise absorption of the impact energy. The principal object of this invention is to provide energy absorbing devices which exhibit peak load-to-plastic load ratios of from 3 to 1. Another object of this invention is to provide a blastresistant barrier, such as a wall or roof structure, incor -porating a panel structure and the present energy absorbing device, which exhibits significantly reduced dynamic reactions. The reduced dynamic reactions in such structures: (a) provides economies in the material and construction of the building framework and the foundation; and (b) permits the span of the panel structure of a given strength to be significantly increased, or conversely permits the strength requirements of a panel of given span to be significantly reduced. Still another object of this invention is to provide an energy absorbing device of the type adapted to be interposed between a source of anticipated dynamic impact loads and a structure which is to be protected from such dynamic impact loads. In accordance with the present invention, an energy absorbing device is provided comprising a faceplate, a base, and a row of spaced-apart permanently deformable sidewalls aligned in generally parallel relation relative to each other and extending transversely of the faceplate. The sidewalls have opposite edges connected to the faceplate and to the base. Each of the sidewalls is partially bent along at least one bend line which is spaced from and extends generally parallel with the faceplate and the base. The arrangement is such that upon the occurrence of substantial impact upon the faceplate, the sidewalls will permanently deform about the bend lines and about the opposite edges thereof to absorb the impact energy transmitted. In one preferred form, the device is in the form of a continuous metal sheet and is fabricated by roll forming or break forming operations. The faceplate has opposite edges adjoined to corresponding edges of the sidewalls, and the base comprises mounting flanges adjoined to corresponding opposite edges of the sidewalls and extending laterally outwardly thereof. The sidewalls include first segments which are oppositely inclned -- preferably converging -from the faceplate toward the bend line; and second segments which are oppositely inclined -- preferably diverging -from the bend lines toward the mounting flanges. The acute angles formed between each of the first segments and the plane of the faceplate and between each of the second segments and the plane of the mounting flanges is greater than 20 angular degrees and less than 75 angular degrees. To achieve a peak load-to-plastic load ratio substantially equal to unity, the acute angles have a value of from 20 to 60 angular degrees. The integrally formed device finds particular utility in blast-resistant barriers, such as wall or roof structures. The device exhibits useful energy absorbing capacities when formed from sheet metal having a thickness of from 0.121 to 0.342 centimeter. In- a second preferred form, the faceplate and the base are relatively thick plate members serving as anvils. The sidewalls may comprise structural angles, bent plates or the like, each having its opposite longitudinal edges secured, as by fillet welding, to the confronting interior faces of the plate members. This form of the present device exhibits a useful energy absorbing capacity of approximately 480 kips when the sidewalls have a thickness of about 0.635 centi meter. Sidewall thicknesses in excess of 0.635 centimeter will provide capacities greater than 480 kips. In drawings which illustrate embodiments of the invention, FIGURE 1 is a fragmentary isometric view illustrating one preferred embodiment of the energy absorbing device of this invention; FIGURE 2 is an end view schematically illustrating the device of FIGURE 1; FIGURES 3 and 4 are end views illustrating the loading and collapse of the device of FIGURE 1; FIGURE 5 is a graphical presentation of the general rela tionship between the strength of the present energy absorbing device and the thickness of the steel from which the device is fabricated; FIGURES 6 to 8 are end views schematically illustrating alternative configurations of the energy absorbing device of this invention; FIGURE 9 is a cross-sectional view, taken along the line 9 9 of FIGURE 10, illustrating a blast-resistant barrier incorporating the energy absorbing device of FIGURE 1; ; FIGURE 10 is a cross-sectional view taken along the line 10 10 of FIGURE 9; FIGURES 11 through 14 are side views schematically illus trating the manner in which the present blast resistant barrier absorbs the transmitted blast load energy; IE 15 is a plan view of a second preferred embodiment of the present energy absorbing device; FIGURE 16 is a fragmentary cross-sectional isometric view as viewed from the line 16-16 of FIGURE 15; FIGURES 17 to 21 are end views illustrating alternative arrangements of the device of FIGURE 16; and FIGURES 22 and 23 are side views schematically illustrating the device of FIGURE 16 positioned between a source of anticipated dynamic impact loads and the structural framework of a building. FIGURE 1 illustrates one preferred form of the present energy absorbing device 30 which is fabricated from sheet metal by, for example, brake forming operations. The device 30 comprises, in general, a faceplate 31, a base in the form of mounting flanges 32, 33 which are coplanar and preferably generally parallel to the faceplate 31, and sidewalls 34, 35 which adjoin opposite edges 36 of the faceplate 31 and connect the faceplate 31 to adjacent inner edges 37 of the mounting flanges 32, 33. In accordance with this invention, each of the sidewalls 34, 35 is partially bent along at least one bend line 38 which is spaced from and extends generally parallel with the faceplate 31 and with the plane of the mounting flanges 32, 33. The arrangement is such that, as illustrated in FIGURES 3 and 4, upon the occurrence of substantial impact schematically illustrated by the arrows L upon the faceplate 31, the sidewalls 34, 35 will permanently deform about the bend lines 38 to absorb the impact energy transmitted. The sidewalls 34, 35 (FIGURE 2) include first segments 39 which are oppositely inclined from the faceplate 31 toward the bend lines 38, and second segments 40 each of which is inclined from the bend line 38 toward the mounting flanges 32, 33 and in a direction opposite to that of the adjoining first segment 39. In the preferred arrangement, the first segments 39 are converging segments and the second segments 40 are diverging segments. In addition, each of the segments 39, 40 has a width 60 which is at most equal to or less than one-half the width 61 of the faceplate 31. The bend lines 38 preferably reside midway between the faceplate 31 and the plane of the mounting flanges 32, 33. The arrangement is such that as the device 30 collapses as illustrated in FIGURES 3 and 4 the sidewalls 34, 35 will permanently deform about the bend lines 38 without contacting each other as at the bend lines 38. Such contact is highly undesirable since it introduces unpredictable stresses which would affect the predictability of the load at which the device 30 fails. The device 30 has an overall height indicated at 62 in FIGURE 2. The distance through which the faceplate 31 moves under load toward the flanges 32, 33 is herein termed the deformable distance and is identified in FIGURE 3 by the dimension line 63. Because of the folding (FIGURE 4) of the sidewalls 34, 35, the available deformable distance 63 is always less than the overall height 62 -- compare FIGURES 2 and 3. It will also be observed in FIGURE 2 that each of the sidewalls 39 is inclined at an acute angle 41 relative to the plane of the faceplate 31; and that each of the second segments 40 is inclined at a second acute angle 42 relative to the plane of the mounting flanges 32, 33. Load tests have been conducted on various specimens of the present energy absorbing device 30 to determine the effect of the nominal thickness of the sheet metal and of the value of the acute angles 41, 42 on the peak load-to-plastic load ratio. As a result of those tests it has been determined (1) that for acute angles 41, 42 of 90 angular degrees, the peak load-to-plastic load ratio varies from 4.33 to 5.83; (2) that for acute angles 41, 42 of 75 angular degrees, the peak load-to-plastic load ratio varies from 1.9 to 3.06; and (3) that for acute angles 41, 42 of 60 angular degrees, the peak load-to-plastic. load ratio varies from 1;0 to 1.2. The test results indicate that the acute angles 41, 42 may have a value of from 20 to 75 angular degrees, and preferably from 20 to 60 angular degrees. The device 30 may be formed from sheet metal having a nominal thickness of from 0.121 to 0.342 centimeter. A general relationship between the strength of the device 30 and the nominal thickness of the sheet metal from which the device 30 is fabricated has been developed. That general relationship, graphically presented in FIGURE 5, indicates that the strength of the device 30 increases curvilinearly within increasing steel thickness. Alternative embodiments of the present energy absorbing device are schematically illustrated in FIGURES 6 through 8. FIGURE 6 illustrates a device 39' wherein the sidewalls 34', 35' include diverging first segments 39' and converging second segments 40'. FIGURES 7 and 8 illustrate a device 30" wherein the sidewalls 34", 35" have a sawtooth profile, each of which presents plural bend lines 38". In the device 30" of FIGURE 7, the sidewalls 34", 35" include converging first segments 39". In the device 30" of FIGURE 8, the sidewalls 34", 35" include diverging first segments 39". BLAST-RESISTANT BARRIER: FIGURES 9 and 10 illustrate a blast-resistant barrier 45 useful as a wall or roof structure. The barrier 45 comprises spaced-apart generally parallel frame members 46 which constitute members of the structural framework of a building. A panel structure 47 is provided which spans the distance between the frame members 46 and which is adapted to undergo permanent deformation on application of a blast load. Support means -- energy absorbing devices 30 -- are provided, one interposed between each of the frame members 46 and the panel structure 47. The support means 30 support the panel structure 47 spaced from the frame members 46 and preferably extend continuously along the length of the frame members 46 between the opposite longitudinal sides of the panel structure 47. As best shown in FIGURE 10, the panel structure 47 essentially comprises a plurality of cellular elements 48 erected in side-by-side interlocked relation. Each of the cellular elements 48 comprises a corrugated outer sheet 49 presenting alternating crests 50 and valleys 51 connected by inclined webs 52; and a correlative lower metal sheet 53 secured to contiguous portions (the valleys 51) of the outer sheet 49. The cellular elements 48 extend transversely of the energy absorbing devices 30 and are secured to the faceplates 31 by one or more fasteners 54. Adjacent ones of the cellular elements 44 may be connected by any suitable means, such as by a male and female joint 55. If desired, the barrier 45 may also include a decorative outer cover, such as profiled facing sheets 56. The facing sheets 56 are secured to and supported on subgirts 57. The subgirts 57 extend transversely of the cellular elements 48 and are secured to the cellular elements 48 at spaced locations therealong. Thermal insulation 58 may be provided in the space between the cellular elements 48 and the facing sheets 47. It is to be understood that the blast-resistant capacity of the barrier 45 is provided substantially entirely by the cooperative contribution of the cellular elements 48 and the energy absorbing devices 30. The facing sheet 56, the subgirts 57 and the thermal insulation 58 do not add significantly to the blast-resistant capacity and are provided solely for the purpose of improving the aesthetic appearance of the barrier exterior face to improve the thermal efficiency of the barrier 45. The present blast-resistant barrier 45 may be erected-on a single span condition such as schematically illustrated in FIGURES 11 or 14; or on multiple span conditions, such as the double span illustrated in FIGURE 9. The manner in which the present blast-resistant barrier 45 absorbs dynamic impact energy transmitted thereto will now be described with reference to FIGURES 11 through 14. In FIGURE 11, the panel structures 47 are erected on a simple or single span condition. Upon the occurrence of a blast adjacent to the barrier 45, a substantially uniform dynamic impact load represented by the group of arrows L is applied to the exterior face of the panel structures 47. The initial effect of the dynamic impact load L is the deflection of the panel structures 47 through an incremental distance indicated at 59 in FIGURE 12. As the dynamic impact load increases the resistance to deflection of the panel structure 47 and of the energy absorbing devices 30 likewise increases. At a first peak resistance, the support means or energy absorbing devices 30 will collapse toward the frame members 46, compare FIGURES 12 and 13. During collapse of the energy absorbing devices 30, the sidewalls 34, 35 thereof (FIGURES 3 and 4) will permanently deform about the bend lines to absorb a significant portion of the impact energy transmitted. The strength of the devices 30 normally is such that 50% of the impact energy transmitted is absorbed during collapse of the devices 30. Following collapse of the devices 30, the panel structure will undergo permanent deformation (FIGURE 14) at a second peak resistance which is greater than the first peak resistance. The permanent deformation of the panel structures 47 will absorb the residual impact energy transmitted. It should now be apparent that in the absence of the support means 30, the blast moment must be resisted mainly by the cellular elements 48 and in part by the frame members 46. However, in accordance with this invention, the introduction of the support means 30 provides a barrier which exhibits reduced dynamic reactions. Thus the present invention provides economies in the material and construction of the building framework and the foundation; and permits the span of the panel structure of a given strength to be significantly increased, or conversely permits the strength requirements of a panel structure of given span to be significantly reduced. ENERGY. ABSORBING PAD: A modified form of the present energy absorbing device may be used to protect a structure against the damaging effects of a source of anticipated dynamic impact loads. Such a situation is illustrated in FIGURED 22 and 23. FIGURE 22 schematically illustrates an energy absorbing pad 65 of this invention secured to a suitable support such as a structural column 66. The pad 65 includes a faceplate 67, a base plate 68 spaced-apart therefrom and parallel therewith, and a crushable core 69 extending between and connecting the plates 67, 68. The pad 65 is positioned in confronting relation and adjacent to an elbow 70 of a high pressure conduit 71. The high pressure conduit 71 conveys high pressure fluids in the direction of the arrow 72. Thus positioned, the pad 65 is adapted to restrain the whipping action of the conduit 75 and to absorb the dynamic impact energy thereof should a crack, such as illustrated in dotted outline at 73, develop in a conduit segment 74 downstream of the elbow 70. Should the conduit 71 fracture at the location 73 as shown in FIGURE 23, the issuing high pressure fluids provide a jet force represented by the arrows 75 which whips the broken conduit 71 at a high velocity and with enormous kinetic energy against the faclat 67. The line of action of ; jet force 75 is indicated by the arrow 76. The kinetic energy of the high velocity broken conduit 71 is absorbed by wrinkle-buckling of the elements of the crushable core 69. The pad 65 exhibits a peak load-to-plastic load ratio substantially equal to unity. Therefore, when the broken conduit 71 impacts the faceplate 67, the resistance to crushing of the core 69 increases substantially linearly to a peak resistance and thereafter remains substantially equal to the peak resistance. The present pad 65 eliminates the relatively high, buckle-initiating peak loads encountered in prior art devices. Thus the structural strength requirements of the structural column 66 or other suitable pad supports is significantly less than that required when using prior art energy absorbing devices. Various embodiments of the energy absorbing pad 65 are illustrated in FIGURES 15 through 21. In view of the similarities between this pad and the energy absorbing devices 30 of FIGURES 1, 6 to 8, corresponding numerals will be employed to identify corresponding parts heretofore described. It will be observed in FIGURE 16 that the core 69 comprises at least one (two in this embodiment) set 77 of sidewalls 34, 35. The sidewalls 34, 35 of each set 77 present converging first segments 39 and diverging second segments 40. The segments 39, 40 of each sidewall 34 (35) are joined at the bend line 38. In the preferred arrangement, the bend lines 38 reside substantially midway between the plates 67, 68. To maximize the load absorbing capacity of the pad 65, the sidewalls 34, 35 may and preferably extend continuously between the opposite ends 78 (FIGURE 15) of the faceplate 67 Each of the sidewalls 34, 35 has its opposite ends secured to the plates 67, 68 by any suitable means, such as fillet welds 79 (FIGURE 16). To facilitate securement of the pad 65 to the support (column 66), the base plate 68 presents opposite side portions 80 and opposite end portions 81 which extend outwardly beyond the corresponding opposite sides 82 and opposite ends 78 of the faceplate 67. Apertures 83 are provided, for example at the corners of the base plate 68, which receive fasteners for securing the pad 65 to the support in the manner illustrated in FIGURE 22. Two properties of the present energy absorbing pad are of significant important. These are the energy absorbing capacity and the deformable distance of the pad. The energy absorbing capacity of the present pad is a function of the number of sets 77 of sidewalls which constitute the core 69. The pad 65 (FIGURE 16), for example, has two sets 77 of sidewalls and has an energy absorbing capacity of pre#'etermined value. Pads 65A, 65B (FIGURES 17 and 18) may be provided which have a single set 77 of sidewalls. The pads 65A, 65B will exhibit an energy absorbing capacity which is substantially equal to one-half that of the pad 65 (FIGURE 16). A pad 65C (FIGURE 19) has a core consisting of four sets 77 of sidewalls and will exhibit an energy absorbing capacity substantially equal to twice that of the pad 65 (FIGURE 16). A pad 65D (FIGURE 20) has a core consisting of one set 84 of three of the sidewalls 34 and one set 85 of three of the sidewalls 35. The pad 65D will exhibit a load absorbing capacity approximately threefourths that of the pad 65C. In FIGURE 16, the location of the faceplate 67 following collapse of the sidewalls 34, 35 is illustrated in dotted outline. It will be observed that the faceplate 67 moves through the deformable distance 63 of the pad 65. The pads 65 of FIGURES 16, 17, 19 and 20 have identical deformable distances 63 but different energy absorbing capacities. The total energy absorbing capacity of the present pad may be varied without varying the deformation distance D. The deformation distance 63 may be varied by changing the acute angles 41, 42 or by stacking two or more of the pads. In FIGURE 18, the core 69 presents acute angles 41, 42 which are shallower than those of the core 69 of FIGURE 17. Consequently the pad 65B has a deformation distance 63' which is less than the deformation distance 63 of the pad 65A. FIGURE 21 illustrates a pad 84 comprising a faceplate 67, a base plate 68, and an intermediate plate 85. Two sets 77 of the sidewalls are provided between the faceplate 67 and the intermediate plate 85. Two additional sets 77' are provided between the base plate 68 and the intermediate plate 85. The pad 84 exhibits an energy absorbing capacity substan tiaily equal to that of the pad 65 of FIGURE 16 but which has a deformable distance 63" substantially equal to twice the deformable distance 63 of the pad 65 (FIGURE 16). The present invention provides an energy absorbing pad wherein the load absorbing capacity may be varied without increasing the deformable distance; or conversely wherein the deformable distance may be varied without changing the load absorbing capacity of the pad. In addition, the energy absorbing capacity of the pad may also be changed by varying the thickness of the sidewalls 34, 35. An energy absorbing pad suitable for use in the environment illustrated in FIGURES 22 and 23 must have an energy absorbing capacity equal to or greater than about 480 kips. It has been determined that a pad similar to that illustrated in FIGURES 15 and 16 wherein the faceplate 67 has a width and length equal to 2 feet (0.61 meter), wherein the sidewalls have an overall length of 2 feet (0.61 meter) and a thickness of 0.25 inch (0.64 centimeter) will exhibit an energy absorbing capacity of approximately 480 kips.

Claims: CLAIMS: 1. An energy absorbing device comprising: a faceplate; a base confronting said faceplate and being spaced from and generally parallel therewith; and a row of spaced-apart permanently deformable sidewalls aligned in generally parallel confronting relation relative to each other and extending transversely of said faceplate, said sidewalls having opposite edges connected to said faceplate and to said base, each of said sidewalls being partially bent along at least one bend line spaced from and extending generally parallel with said faceplate and said base; whereby upon the occurrence of dynamic impact loads upon said faceplate, each of said sidewalls will permanently deform about the bend line and about the opposite edges thereof to absorb the impact energy transmitted. 2. The device of Claim 1 wherein said sidewalls include: first segments which are oppositely inclined from said faceplate toward the bend lines; and second segments each of which is inclined from the bend line toward said base and in a direction opposite to that of the adjoining first segment. 3. The device of Claim 2 wherein said first segments are converging segments. 4. The device of Claim 2 wherein said first segments are diverging segments. 5. The device of Claim 2 wherein the acute angle between each of said first segments and the plane of said fa-eplate is greater than 20 angular degrees and less than 75 angular degrees. 6. The device of Claim 2 or 5 wherein the acut angle between each of said second segments and the plane of said base is greater than 20 angular degrees and less than 75 angular degrees. 7. The device of Claim 1 wherein each of said sidewalls has a sawtooth profile and presents plural bend lines. 8. The device of Claim wherein the bend lines reside substantially midway between said faceplate and said base. 9. The device of Claim 1 wherein said device is in the form of a continuous metal sheet; said faceplate having opposite sides adjoined to corresponding first edges of said sidewalls; and said base comprising mounting flanges having confronting edges adjoined to corresponding opposite edges of said sidewalls and extending laterally outwardly thereof. 10. The device of Claim 9 wherein the width of each of said first segments is at most equal to one-half the width of said faceplate. 11. The device of Claim 9 wherein said mounting flanges extend outwardly beyond the opposite edges of said faceplate. 12. The device of Claim 1 wherein said sidewalls reside substantially entirely between opposite sides of said faceplate and extend continuously between opposite ends of said faceplate. 13. A blast-resistant barrier comprising: spaced-apart generally parallel frame members a panel structure spanning the distance between said frame members and being adapted to undergo plastic deformation on application of dynamic impact loads; and support means, one interposed between each of said frame members and said panel structure, supporting said panel structure spaced from said frame members, each of said support means including at least two spaced-apart permanently deformable sidewalls extending between said panel structure and the adjacent frame member, each of said sidewalls being partially bent along at least one bend line disposed between opposite edges thereof and extending parallel with the adjacent frame members; ; whereby upon the occurrence of dynamic impact loads upon said barrier said support means will collapse toward said frame members at a first peak resistance, and said panel structure will undergo plastic deforma tion at a second peak resistance which is greater than said first peak resistance to absorb the impact energy transmitted. 14. The blast-resistant barrier of Claim 13 wherein each of said support means extends continuously along the adjacent frame member and between opposite longitudinal sides of said panel structure. 15. The blast-resistant barrier of Claim 13 wherein each of said support means is formed from sheet metal having a nominal thickness of from 0.121 to 0.342 centimeters. 16. The blast-resistant barrier of Claim 13 wherein each of said sidewalls has a sawtooth profile and presents plural bend lines. 17. The blast-resistant barrier of Claim 13 wherein each of said support means comprises: a faceplate secured to said panel structure; mounting flanges secured to the adjacent frame members; and said sidewalls connecting opposite outer edges of said faceplate to adjacent inner edges of said mounting flanges. 18. The blast resistant barrier of Claim 17 wherein the width of each first segment is at most equal to one half the width of said faceplate. 19. The blast-resistant barrier of Claim 17 wherein the bend lines reside substantially midway between said faceplate and said mounting flanges. 20. The blast-resistant barrier of Claim 17 wherein said sidewalls include: first segments which are oppositely inclined from said faceplate toward the bend lines; and second segments each of which is inclined from the bend line in a direction opposite to that of the adjoining first segment. 21. The blast-resistant barrier of Claim'20 wherein said first segments are converging segments. 22. TLe blast-resistant barrier of Claim 20 wherein said first segments are diverging segments. 23. The blast-resistant barrier of Claim 20 wherein the acute angle between each of said first segments and said faceplate is greater than 20 angular degrees and less than 75 angular degrees. 24. The blast-resistant barrier of Claim 20 or 23 wherein the acute angle between-each of said second segments and the face of the adjacent frame member is greater than 20 angular degrees and less than 75 angular degrees. 25. In combination, a source of anticipated dynamic impact load, a structure confronting said source of antici pated dynamic impact load and a device interposed between said structure and said source and adapted to sustain dynamic impact load from said source by ab sorption of the impact energy transmitted, said device comprising: a base plate adjacent to said structure; a faceplate confronting said source and extending sub stantially parallel with said base plate; and at least two spaced-apart permanently deformable side walls extending between and connected to said base plate and to said faceplate, each of said sidewalls being partially bent along at least one bend line spaced from and generally parallel with said faceplate and with said base plate; whereby upon the occurrence of said dynamic impact load upon said faceplate, each of said sidewalls will permanently deform about the bend line to absorb the impact energy transmitted. 26. The combination of Claim 25 wherein said sidewalls extend continuously between opposite edges of said faceplate. 27. The combination of Claim 25 wherein the bend lines reside. substantially midway between said faceplate and said base plate. 28. The combination of Claim 25 wherein said sidewalls include: first segments which are oppositely inclined from said faceplate toward the bend lines; and second segments each of which is inclined from the bend line in a direction opposite to that of the adjoining first segment. 29. ¯ The combination of Claim 28 wherein said first segments are converging segments. 30. The combination of Claim 28 wherein said first segments are diverging segments. 31. The combination of Claim 28 wherein the acute angle between each of said first segments and said faceplate is greater than 20 angular degrees and less than 75 angular degrees. 32. The combination of Claim 28 or 31 wherein the acute angle between each of said second segments and said base plate is greater than 20 angular degrees and less than 75 angular degrees.

Inventors: MING LONG TING, RAYMOND
Applicants: H.H. ROBERTSON COMPANY
Application year: 1979
Main classification: E04B1
IPC codes: E04B1, F16F7