DOI: 10.5061/dryad.905qfttrx
title: Bearing capacity of rectangular concrete-filled steel tube (CFST) and dumbbell shaped CFST under axial compression, eccentric compression, and pure bending stress states

description: The fiber model method utilizes material constitutive relationships and
 internal force synthesis techniques to accurately and conveniently
 determine the internal force of the section, without the need to establish
 an element stiffness matrix. It is simple and practical and has been
 widely used in the bearing capacity analysis of concrete-filled steel
 tubes (CFST). The material constitutive relationship is an important
 factor determining the calculation accuracy of the fiber model method.
 This article studies and establishes a modified model for the constitutive
 relationship of CFST materials, and establishes the fiber model method for
 the mechanical performance analysis of rectangular CFST and dumbbell CFST,
 respectively. Based on the geometric size parameters and material strength
 parameters (such as "length", "Diameter",
 "Width", "Thickness", "Yield strength",
 "Compressive strength", etc.) in the experimental database, the
 fiber model method is used to calculate the bearing capacity of the
 component and compare it with the "Test values" in the
 experimental data to verify the calculation accuracy and applicability of
 the fiber model method and the established constitutive relationship. The
 test database contains a total of 6 tables. Table 1.1 shows the axial
 compression test database for rectangular sections, with a total of 428
 sets of data; Table 1.2 shows the pure bending test database for
 rectangular sections, with a total of 84 sets of data; Table 1.3 shows the
 database of compression bending tests for rectangular sections, with a
 total of 208 sets of data. Table 2.1 shows the database of axial
 compression tests for dumbbell shaped sections, with a total of 20 sets of
 data; Table 2.2 shows the pure bending test database for dumbbell shaped
 sections, with a total of 4 sets of data; Table 2.3 shows the database of
 compression bending tests for dumbbell shaped sections, with a total of 30
 sets of data.
description: (1)The test data is derived from domestic and
 international literature, involving different concrete strength
 indicators. For the convenience of comparative analysis, this paper
 unifies the different strength indicators into axial compressive strength
 <em>f</em><sub>ck</sub>: when the compressive strength of the cylinder,
 <em>f</em><sub>c</sub><sup>’</sup>&lt;=40MP, the compressive strength of the cube, <em>f</em><sub>cu,k</sub>=1.25*<em>f</em><sub>c</sub><sup>’</sup>; otherwise, <em>f</em><sub>cu,k</sub>=<em>f</em><sub>c</sub><sup>’</sup>+10. The axial compressive strength<em> f</em><sub>ck</sub> can be calculated using the formula <em>f</em><sub>ck</sub>=0.88x0.4x(<em>f</em><sub>cu,k</sub>)<sup>7/6</sup>. (2) The test database uses parameters such as length, diameter, and eccentricity to describe the member information. When these parameters are not directly provided in the reference literature, they are obtained by converting other known parameters in the original literature. (3) In the absence of a specific value for the elastic modulus of the steel pipe in the literature, a standardized value of Es = 206,000 MPa is uniformly adopted to facilitate computational analysis. (4) In order to make the test database clear at a glance, the length unit of the test database is mm, the strength unit is MPa, the force unit is kN, and the moment unit is kNm. When the units of various data in the reference literature are different from those in the test database, unit conversion is performed.
description: # Test database for bearing capacity of rectangular CFST and dumbbell
 shaped CFST under axial compression, eccentric compression, and pure
 bending stress states The fiber model method utilizes material
 constitutive relationships and internal force synthesis techniques to
 accurately and conveniently determine the internal force of the section,
 without the need to establish an element stiffness matrix. It is simple
 and practical, and has been widely used in the bearing capacity analysis
 of concrete filled steel tube (CFST). The material constitutive
 relationship is an important factor determining the calculation accuracy
 of the fiber model method. This article studies and establishes a modified
 model for the constitutive relationship of CFST materials, and establishes
 the fiber model method for the mechanical performance analysis of
 rectangular CFST and dumbbell CFST, respectively, Based on the geometric
 size parameters and material strength parameters (such as
 "length", "Diameter", "Width",
 "Thickness", "Yield strength", "Compressive
 strength", etc.) in the experimental database, the fiber model method
 is used to calculate the bearing capacity of the component and compare it
 with the "Test values" in the experimental data to verify the
 calculation accuracy and applicability of the fiber model method and the
 established constitutive relationship. ## Data description The test
 database contains a total of 6 tables. Table 1.1 shows the axial
 compression test database for rectangular sections, with a total of 428
 sets of data; Table 1.2 shows the pure bending test database for
 rectangular sections, with a total of 84 sets of data; Table 1.3 shows the
 database of compression bending tests for rectangular sections, with a
 total of 208 sets of data. Table 2.1 shows the database of axial
 compression tests for dumbbell shaped sections, with a total of 20 sets of
 data; Table 2.2 shows the pure bending test database for dumbbell shaped
 sections, with a total of 4 sets of data; Table 2.3 shows the database of
 compression bending tests for dumbbell shaped sections, with a total of 30
 sets of data. In Tables 1.1 to 1.3 and 2.1 to 2.3: "References"
 represents the source of data. "Length" represents the length of
 the component, represented by the symbol *L*, with units in mm.
 "Width" represents the width of the short side of a rectangular
 section, represented by the symbol *B*, with units in mm.
 "Height" represents the width of the long side of a rectangular
 section, represented by the symbol *H*, with units in mm.
 "Diameter" represents the cross-sectional diameter of a single
 circular tube at both ends of a dumbbell shaped section, represented by
 the symbol *D*, with units in mm. "Thickness" represents the
 wall thickness of the outer steel pipe of the component, represented by
 the symbol *t*, with units in mm. "Eccentricity" represents the
 horizontal distance along the strong axis between the point of application
 of the test load and the central axis of the component section,
 represented by the symbol *e*, with units in mm. "Eccentricity
 ratio" represents the ratio of the eccentricity of a dumbbell shaped
 section to the radius of rotation of the section, usually expressed as
 *e*/2*i*, where *i* represents the radius of rotation of the combined load
 surface in the strong axis direction of the section. "Slenderness
 ratio" represents an important parameter reflecting the stability of
 a component, which is related to the cross-sectional form and is
 represented by the symbol *λ*. "Height-thickness ratio"
 represents the ratio of the height of a rectangular section to the
 thickness of a steel pipe. A reasonable height thickness ratio can ensure
 the full play of the bearing capacity of the component, represented by the
 symbol *H*/*t*. "Yield strength" represents the yield strength
 of the steel pipe, represented by the symbol *f*y, with units in MPa.
 "Compressive strength" represents the standard compressive
 strength of concrete, represented by the symbol *f*ck, with units in MPa.
 "Elastic modulus of steel" represents the elastic modulus of
 steel, represented by the symbol *E*s, with units in MPa. "Test
 values" represent the experimental results of the component's
 ultimate bearing capacity, with Table 1.2, Table 1.3, Table 2.1, and
 Table2.3 representing compressive bearing capacity. Table1.2 and Table2.2
 representing flexural bearing capacity, respectively. The symbol *N*u is
 used for both compressive and flexural bearing capacity, with units in kN,
 and the symbol *M*u is used for flexural bearing capacity, with units in
 kNm. Note: (1)The test data is derived from domestic and international
 literature, involving different concrete strength indicators. For the
 convenience of comparative analysis, this paper unifies the different
 strength indicators into axial compressive strength *f*ck: when the
 compressive strength of the cylinder, *f*c’&lt;=40MP, the compressive
 strength of the cube, *f*cu,k=1.25**f*c’; otherwise, *f*cu,k=*f*c’+10. The
 axial compressive strength *f*ck can be calculated using the formula
 *f*ck=0.88x0.4x(*f*cu,k)7/6. (2) The test database uses parameters such as
 length, diameter, and eccentricity to describe the member information.
 When these parameters are not directly provided in the reference
 literature, they are obtained by converting other known parameters in the
 original literature. (3) In the absence of a specific value for the
 elastic modulus of the steel pipe in the literature, a standardized value
 of Es = 206,000 MPa is uniformly adopted to facilitate computational
 analysis. (4) In order to make the test database clear at a glance, the
 length unit of the test database is mm, the strength unit is MPa, the
 force unit is kN, and the moment unit is kNm. When the units of various
 data in the reference literature are different from those in the test
 database, unit conversion is performed.