A finite element analysis model for the behaviour of cold-formed steel members

A finite element analysis model for the post-local buckling behaviour of co ld-formed steel (CFS) members subjected to axial compression has been devel oped. The finite element model consists of a Total Lagrangian nonlinear 9-n ode "assumed strain" shell finite element, and experimental-based material properties models to represent the body of the CFS sections. Experimentally derived residual stress variations, and initial geometric imperfections ha ve also been incorporated. A special loading technique and a displacement s olution algorithm were employed to obtain a uniform displacement condition at the loading edges. Details of a test program involving 20 non-perforated , and perforated cold-formed stub-column steel sections have been presented in the second part of the paper. The comparison between the test results, and the finite element results was performed for axial and lateral displace ment behaviour, buckling loads, ultimate loads, and axial stress distributi on. The comparison forms the basis for the evaluation of the efficiency, an d the accuracy of the finite element model, and it indicated that the finit e element analysis model constructed herein gives accurate and consistent r esults for the behaviour of the cold-formed steel members subjected to axia l compression. (C) 1998 Elsevier Science Ltd. All rights reserved.