On Nonlinear Buckling and Collapse Analysis using Riks Method

Nonlinear analysis using Riks method is suitable for predicting buckling, post-buckling, or collapse of certain types of structures, materials, or loading conditions, where linear or eigenvalue method will become inadequate or incapable, especially when nonlinear material, such as plasticity, is present, or post-buckling behavior is of interest. These structures usually undergo finite deformations due to complicated loadings or material plasticity before buckling actually occurs, which changes system matrices, and thus, makes the eigenvalue analysis inaccurate, difficult, or even impossible to perform. This study intends to demonstrate the use of Riks method in the nonlinear analysis of buckling and post-buckling behaviors of a flexible structure under bending and compressive loads. The null-point on load-displacement curve is used as criteria for the onsite of instability. The predicted results from finite element analysis compare well with testing data.