Influence of residual stresses on the buckling behaviour of thin-walled, composite tubes with closed cross-section – Numerical and experimental investigations

The aim of this research is to investigate the influence of residual stresses on the behaviour of thin-walled laminates during compression until failure. We investigate the compression of a squared cross-section, GFRP columns with dimensions: (width × height × thickness): 80 × 80 × 2 mm. The length of the tubes is equal to 250 mm. The material used to manufacture the specimens was eight-layered pre-preg and we analysed six combinations of angular arrangements. The autoclaving technique was employed to produce the samples. In this paper, a new FE model of tubes’ compression including residual stresses from the manufacturing process is presented. The FE model where residual stresses are not taken into account has been underestimated by the real structures’ behaviour. Therefore, the first part of the study is devoted to preparing a simplified model of the curing process, while in the second the manufacturing and curing stresses are transferred to the model of compression. Backed by experimental data, the study shows that residual stresses have a significant influence on buckling performance, which finds confirmation in the experiments.