Bearing capacity of rectangular concrete-filled steel tube (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 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 o..., (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 fck: when the compressive strength of the cylinder, fc’<=40MP, the compressive strength of the cube, fcu,k=1.25*fc’; otherwise, fcu,k=fc’+10. The axial compressive strength fck can be calculated using the formula fck=0.88x0.4x(fcu,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 d..., , # 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\", \"Wid...