Simplified analytical model to predict nonlinear mechanical responses of flexible composite sheet subjected to out-of-plane loading

This paper presents a simplified analytical model for predicting nonlinear mechanical responses of flexible composite sheet (FCS) subjected to out-of-plane loading. New geometric model based on three-parameter exponential function is proposed to depict 3D funnel-like geometric shape of out-of-plane loaded FCS, and nonlinear constitutive model is then derived to describe the load-displacement curves of out-of-plane loaded FCS. Finally, model parameters are determined through the principle of minimum potential energy. In order to verify new models, out-of-plane loading tests are performed on PWF (plain woven fabric) polyester reinforced HNR (hydrogenated nitrile rubber) composite sheets with three length-width ratios of 1, 2 and 3, and the predictions agree well with the experiments, demonstrating the practical and effective use of the proposed model.