Modelling and testing of the snap-through process of bi-stable cross-ply composites

Bi-stable response of cross-ply composites is modelled when snap processes are trigged by a vertical force and the laminate is supported at four points. The model is based on the Rayleigh-Ritz technique. Non-linear von Kármán strains, non-uniform curvatures and uniform through-the-thickness normal strain are included in the analysis. The analysis has been carried out step by step, by small increments of the applied load. Experiments in four [0/90]T carbon/epoxy laminates have been carried out for comparison in a test configuration that fulfils the requirements of the model. The multi-event snap-through and intermediate equilibrium positions have been experimentally observed and recorded. The initial snap-through and snap-back load-displacement curves have been experimentally determined and compared to those corresponding to the proposed model.