Materials characterisation and crash modelling of composite-aluminium honeycomb sandwich material

Composite sandwich materials are extensively used in aerospace, motorsport and other applications that require low-weight, high-stiffness materials with high strength and energy absorption. In Formula 1 vehicles, composite-aluminium sandwich materials are used for the energy absorbing structures and the protective cell for the driver. Generally, the loading and failure mechanisms in sandwich composite materials are well understood. However, their behaviour under crash loading is complex due to the multitude of failure and damage mechanisms that occur and is problematic for finite element modelling. This paper outlines test and material characterisation methods used to model crushing of the aluminium honeycomb, failure of the composite plies and fracture propagation in the sandwich due to transverse tensile loading. A finite element modelling methodology is proposed that allows each of these failure modes to develop independently, or concurrently, and validation is demonstrated at both the coupon and structural level.