Fracture tailoring in 3D printed continuous fibre composite materials using the Phase field approach for fracture

Abstract

Additive Manufacturing is a technology with high potential since it offers a lot of benefits going from lower material waste to flexibility in the component fabrication process. The continuous Carbon Fibre (CF) deposition is an interesting approach since it allows to depose continuous CF bundles following different geometries and avoiding the limitations of current composite manufacturing techniques. Choosing the CF deposition path means also giving the designer the possibility to reinforce areas of the designed component which are subjected to stress concentrations, thus increasing its fracture resistance. In this work, a study on the reinforcement capabilities of this technology is performed, considering different specimen geometries and different geometries for the CF deposition path. Two different geometries are analysed: a V-notch and an Open-Hole specimen, both subjected to tensile loading. To model the fracture scenario, a Phase Field framework is exploited. The V-notch simulation demonstrates the capability of Phase Field to catch both the fracture path and the mechanical response reported in experiments from the literature. In the second part of the paper, the Open Hole Tension test is simulated numerically by means of the same tools described above, taking into consideration different geometries for the reinforcement around the hole. The specimens with different reinforcement geometries show different mechanical responses and crack patterns, thus highlighting the influence of the continuous CF reinforcement geometry on the fracture scenario.