Algorithm study of three-dimensional light gauge steel structures thermal–mechanical coupling based on improved static-dynamic transformation analysis

Abstract

Non-linearity and low-computational efficiency make the thermal–mechanical coupling simulation of the overall structure difficult to achieve with a single static or dynamic analysis. This manuscript combined the efficiency of implicit static analysis and explicit dynamic analysis for calculating large deformations, and realized the transformation of static and dynamic analysis in ABAQUS software. Then, the transformation of static and dynamic analysis applied to the thermal–mechanical coupling numerical simulation of the overall structure. For structural forms with numerous members, significant non-linearity and complex connection contacts, an improved static-dynamic transformation analysis (ISDTA) method was proposed. In the ISDTA method, the criteria for determining and removing members that reach the fire resistance temperature were set to improve the efficiency and convergence of the calculation. A three-dimensional light gauge steel structure calculation model was established. Then, based on the proposed ISDTA method, numerical simulation of thermal–mechanical coupling was carried out to compare the failure model, member deformation and fire resistance temperature of the experimental and numerical simulation models. It was concluded that the proposed ISDTA method could simulate the actual failure model of light gauge steel structures effectively and predict the moment of structural collapse accurately, with an error of 4.1% between the calculated and measured fire resistance times. The method could apply to the thermal–mechanical numerical simulation of the overall structural process from small deformation to collapse in a structural system characterised by “large number of components, significant non-linearity, and complex connection contacts”.