Study on inelastic lateral-torsional ultimate strength of permanent means of access structure

An elastic model based on the Rayleigh–Ritz approach was proposed by Jang and Ma (2011) for analyzing the lateral-torsional buckling (“tripping”) behavior of permanent means of access (PMA) structures which was introduced by the International Maritime Organization (IMO) for a regular inspection of ship structure. This paper extends the elastic model into the inelastic range, using deformation theory and an iterative and incremental formulation. The effects of cross-sectional distortion and plasticity are included. Results obtained using the method are shown to be in a good agreement with nonlinear finite element analysis results.

► An inelastic model based on the Rayleigh-–Ritz approach is proposed. ► Deformation theory and an iterative and incremental formulation are used. ► The effects of cross-sectional distortion and plasticity are included. ► The results used by the proposed method are in a good agreement with nonlinear finite element analysis results.