Benchmark Finite Element Simulations of Postbuckling Composite Stiffened Panels

Abstract

This paper outlines the CRC-ACS contribution to a software code benchmarking exercise as part of the European Commission Project COCOMAT investigating composite postbuckling stiffened panels. Analysis was carried out using MSC.Nastran (Nastran) solution sequences SOL 106 and SOL 600, Abaqus/Standard (Abaqus) and LS-Dyna, and compared to experimental data generated previously at the Technion, Israel and DLR, Germany. The finite element (FE) analyses generally gave very good comparison up to initial postbuckling, with excellent predictions of stiffness, and mostly accurate representations of the initial postbuckling mode shape, leading to fair omparison in deep postbuckling. Accurate modelling of boundary conditions and panel imperfections were crucial to achieve accurate results, with boundary conditions in particular presenting the most critical problem. Comparatively, SOL 106, SOL 600 and Abaqus gave almost identical results, whilst LS-Dyna produced less accurate results in postbuckling. The work in this paper will be compared to parallel FE analyses from other project partners, and conclusions will be made on the efficacy of various software codes for fuselage-representative composite structures.