Geometric nonlinear analysis of asymmetric thin-walled beam-columns

S.L. Chan, S. Kitipornchai

Department of Civil Engineering, University of Queensland, Australia

Received March 1986; revised December 1986

ABSTRACT:

The geometric nonlinear analysis of structures comprising members of asymmetric thin-walled open section is investigated. The geometric stiffness matrix for a thin-walled element is derived, incorporating second order nonlinear strain terms in the governing energy equations. The derived stiffness matrices are used to predict bifurcation loads of a number of structures. An updated Lagrangian formulation, coupled with the numerical arc-length technique, is employed to trace the non-linear load-deflection paths up to the maximum load. Numerical examples of the load-deflection behaviour of eccentrically loaded and restrained unequal angle beam-columns are presented.

Keywords:

asymmetry; beam-columns; geometric nonlinearity; matrices; structural analysis; thin-wall