Modelling the pultrusion process of an industrial L-shaped composite profile

A numerical process simulation tool is developed for the pultrusion of an industrial L-shaped profile. The composite contains the combination of uni-directional (UD) roving and continuous filament mat (CFM) layers impregnated by a polyester resin system specifically prepared for the process. The chemo-rheology and elastic behavior of the resin are obtained by applying a differential scanning calorimetry (DSC) and a dynamic mechanical analyser (DMA), respectively. The process induced stresses and shape distortions are predicted in a 2D quasi-static mechanical analysis. The numerical process model predicts the residual spring-in angle which is found to be close to the one measured from the real pultruded L-shaped products. The residual spring-in angle is further analyzed using the developed simulation tool for different pulling rates. Through-thickness stress variations are found to prevail inside the part such that the UD and CFM layers have different stress levels at the end of the process. The predicted stress pattern is verified by performing a stress calculation using the classical laminate theory (CLT).