FINITE-DEFORMATION THEORY ANALYSIS AND TEST RESEARCH OF ULTIMATE STRENGTH FOR STEEL FRAMES

摘要

Based on the nonlinear continuous medium mechanical theory, this paper proposed an effective method for the analysis of the ultimate strength of steel frames. According to the method, we can derive the geometric stiffness matrix of structures, which can take into account the influence of the axial force, shear and flexural moment on the stiffness of structures. A suitable nonlinear analysis method, which is based on nonlinear continuum mechanics, stress-resultant yield surface and displacement increment Newton-Raphson subincrementation scheme, is successfully applied to the large deformation elastoplastic analysis of the ultimate strength of steel frames. 4 steel frames were tested, and the experimental results were compared with the theoretical predictions, which verified that the presented theoretical method had very high precision and efficiency.