Experimental and numerical studies on forming and failure behaviours of a woven self-reinforced polypropylene composite

This paper investigates forming and failure behaviours of a consolidated woven self-reinforced polypropylene (SRPP) composite through combined stamp forming experiment and finite element analysis. Mechanical properties of a woven SRPP composite were characterised. Constitutive equations were derived as functions of strains using a homogenised orthotropic material model. Specimens with novel geometries, different aspect ratios and fibre orientations were stretch formed in a custom-built press until catastrophic failure. Evolution of principal strains was captured using a real time Digital Image Correlation (DIC) system. A path-dependant failure criterion was developed as a function of deformation modes and invariants of strain tensor. Material and failure models were implemented into a finite element analysis using Abaqus/implicit. Strain path at the pole of specimens, evolution of surface strains, and onset of failure were predicted using a homogenised numerical scheme. Comparison with experimental outcomes demonstrated the high accuracy of the proposed numerical model in predicting deformation and failure behaviours of a thermoplastic composite under a wide range of deformation modes. The model demonstrates the potential to predict formability and failure behaviour of woven self-reinforced thermoplastic composites during manufacturing by eliminating the need to conduct expensive, time consuming trial and error procedures.