Experimental and numerical investigation of the crushing process of composite crash box

Abstract

Due to restrictions to bring down fuel consumption and carbon emissions, the recent research and technology innovations are encouraging automakers to apply new materials in automotive industry for light weight designs. Composites are being increasingly used in the industry because of their benefits over traditional metallic materials including their strength, weight, and reduction in manufacturing time. Along with these benefits, composites also have excellent performance related to energy absorption during impact and crash events. However, due to pressure for price limitations, the studies on applying composite materials mostly concentrate on the high priced elements per unit mass and the parts having significance in security. Crash box is the most distinct part that has those conditions. The fracture process in composite structures is quite complex which involves not only intralaminar failure modes, but also interlaminar failure. Advances in commercial Finite Element Analysis (FEA) software have enabled engineers to realistically simulate the performance of composite components including these failure modes. The thesis work will examine the modelling of crash behaviour of lightweight composite crash boxes in ABAQUS. A benchmarking study is applied to understand the modelling of the intralaminar damage mechanisms with 2D Hashin damage criteria and the delamination with decohesion elements which is called Cohesive Zone Modelling. Moreover, a new crash composite structure has been proposed, manufactured and tested and the results of the Finite Element simulation are compared to experimental results.