Inelastic Analysis of Steel Frame Structures with the Member Endochronic Model

Abstract

For Beams and columns in the nonlinear analysis of structures concerned with earthquake ground motions, member restoring-force model is one of the important aspects for adequate evaluation of structural numerical analyses. The Member Endochronic Model (MEM) is a kind of new restoring-force model for beams and columns. Studies on MEM under compound forces and reversal forces are still going on and some improvements have tried to develop its feasibility. MEM is established on the combined idea of section endochronic description and the member model of the finite element method. The most important feature of MEM is that the section characteristics under compound and reversal forces are described on the concept of section intrinsic time, which makes the section constitutive equation being uniform for monotonic loading or reversal loading and for one-dimensional deformation or compound forces case. This could greatly simplify the computer programming work of structure analysis. After a brief introduction on the establishment of MEM and the method for determining the model parameters, this paper puts the model into the inelastic analysis of plane steel frames to examine the applicability of the model on the simulation analysis of frame structures. The numerical results are represented by a series of section quantities of the member ends including the section intrinsic time. The consequences of the plastic hinge appearance of each member are especially examined to show the adequate description of the model on the frame damage course. The ductility indices of plastic hinges of member ends and the whole structure are also examined. It is shown that MEM is reliable on the push-over analysis of frame structures and the special section description based on the section intrinsic time is convenient for the understanding for the damage state of the structure. Results of the paper show the possibility for the further use of MEM to structural dynamic analysis.