Advanced Inelastic Analysis of Frame Structures Considering Shearing and Warping Deformations

The paper addresses the derivation of a concentrated plastic-hinge finite element modelling for nonlinear analysis Of space steel frames. The interpolation functions considering shearing deformation are adopted and cubic polynomial interpolation functions based on Kollbrnner-Dajdin modified constraint torsion theory are used to consider the warping deformation, with these functions the effect of the secondary shear stress can be taken into account. With the expanded Orbison's yielding surface, the plastic-hinge method used to do nonlinear analysis of space steel frames is derived by introducing elastic-plastic hinge parameter of element cross section. Numerical examples are presented to illustrate the validity and the universality of the proposed approach and the results show the new model is accurate and suitable for the nonlinear analysis of steel frameworks.