Phenomenological investigation on crash characteristics of thin layered CFRP-steel laminates

Abstract

Most energy absorbing structures in automotive applications consist of metals. Those are characterised by high absolute energy absorption (EA) values yet low mass-specific energy absorption (SEAm). In contrast carbon fibre reinforced polymers (CFRP) reach higher SEAm values. The difference however is not a direct consequence of the density, weight specific stiffness or strength. Instead, the failure progression and hence the energy dissipation characteristics of metallic and CFRP structures are different. Whether a combination of the two material types leads to an increase or decrease of the SEA depends on the crash characteristics of the laminate which supposedly depends on the lay-up. The present paper reports on an experimental investigation on the crash behaviour of omega-shaped fibre-metal laminates (FML) composed of unidirectional CFRP prepreg layers and steel-foils under compressive axial loads. A potential of the tested hybrid laminates is proven by an increase of the mass-specific energy absorption value (SEAm) of 58%, compared to CFRP.