Composite Dash Panel Insulation Characterization and Modelling Methodology for Virtual Simulations

Felt-based dash panel insulation materials have traditionally been used as a sound barrier between the engine and passenger compartments in a vehicle to reduce the transmission of engine noise to the occupant space. Their structural performance has been mainly ignored due to the typically low stiffness and strength characteristics. Consequently, studies of the acoustic properties of these materials have been found in literature while no information was found on their mechanical behavior especially in dynamic loading conditions. More stringent requirements for occupant and pedestrian safety imposed by government regulations and the position of these materials in the impact zones of pedestrian head impact have brought attention to the material contribution to the energy absorption during the impact and the need to assess the mechanical properties of these materials. This paper presents tensile, compressive, and multiaxial impact results from tests conducted on two multi-layered felt-based materials at several different thicknesses and the challenges these soft materials present in tensile testing. Effects of thickness and strain rate on each material are discussed. Finally, a material modeling methodology for each material is proposed and verified by comparison of multiaxial test and simulation results.