Springback analysis of thermoplastic composite plates

Abstract

Residual stresses, which are set in the fiber reinforced composites during the laminate curing in a closed form, lead to dimensional changes of composites after extracting from the form and cooling. One of these dimensional changes is called “springback” of the angle sections. Other dimensional changes are warpage of flat sections of composite or displacement of single layers of composite for example. In our case four different lay-ups were analysed (three symmetrical and one unsymmetrical). An analytical model which covers temperature changes, chemical shrinkage during curing and moisture change was used. Also a FEM analysis was done for predicting the springback, and both calculations were compared with the measured data from manufacturer.