Abstract
Contemporary demands on the construction of modern vehicle consist of many contradictory aspects - weight reduction, safety, sustainability, etc... Even though possibilities of currently applied materials, usually metals, seem to be exhausted, there are still enough unusual and unique materials to be engaged in automotive applications. The deformation behaviour of a composite sandwich structure made up of glass/carbon fibre reinforced polymer skins and Rohacell IG-F core material was simulated. FEM simulations were performed on the simplified shell representing skin and solid core model with Puck composite ply failure criterion. The composite skin and sandwich panel were subjected to impact of head-form impactor and influence of the skin lay-up on resulting Head Injury Criterion was evaluated. The design of sandwich panel with objective of Head Injury Criterion minimalization consists of many variables: fibre and matrix material, thickness and lay-up angle of each lamina and material and thickness of the core. Due to this fact, the method of numerical optimization (Adaptive Response Surface Method) was used. The designated structure of laminate lay-up shows a potential in reducing Head Injury Criterion itself, but the use of sandwich structure with foam core extends possibilities of real usability (flexural stiffnes, acoustic insulation, savings in amount of used fibre materials). Resulting design of sandwich composite structure shows the way in construction of passenger car bonnet and possibilities of future HIC reduction, but it needs to be experimentally validated and analysed in terms of applicable production technology (Resin Transfer Mould) and outer skin surface treatment due to the risk of injuries caused by exposure of skins brittle fracture (sharp) surfaces. The applied method of design led to solution, but the method doesn’t provide further knowledge of design parameters influence on performance of the structure.
Keywords: pedestrian safety, HIC, sandwich, optimization, composites