Elastic-plastic finite element analysis for steel-concrete composite beams

The paper describes a new method for nonlinear finite element analysis of prestressed composite beam of steel and concrete. In this method, five key points in full work course of moment-curvature curve are put forward, and their formulas for moment and curvature as well. With the key points, the analytical expression of moment-curvature relationship of the simply supported composite beam is got by least-squares procedure. The model and the program for nonlinear finite element analysis are set up, which can calculate the effect of the concrete crash and the material stiffness strengthen exactly. Two samples of simply supported composite beam are tested. Compared with the tested one, the result given by the method is exact.