Experimental study on the vibro-acoustic properties of fibrereinforced composites with integrated viscoelastic Ethylene-Propylene-Dien-Monomer (EPDM) rubber

摘要

Composite materials offer for automotive applications the specific advantage of lowrnconstructive weight in combination with a high stiffness. For vibro-acoustic applications,rnespecially the low structural weight leads to higher vibration amplitudes due to low forcesrnof inertia and causes undesired sound radiation. A useful approach to eliminate theserndrawbacks and increase the structural damping without adding too much additionalrnweight to the construction is the integration of viscoelastic damping layers in the compositernmaterials during the manufacturing process. In the presented experimental study, differentrntypes of viscoelastic Ethylene-Propylene-Dien-Monomer (EPDM) rubber sheets arernintegrated in the mid-plane of a reference laminate made from carbon textile-reinforcedrnepoxy. The vibro-acoustic properties of the fibre-reinforced multilayered composites –rnabsorption coefficient, sound reduction index, dynamic stiffness and material damping –rnwere measured and compared. As expected, the integration of EPDM sheets in therncomposite leads to higher material loss factors. To identify the vibro-acoustically optimalrnposition of the EPDM layer within the composite lay-up, special simulation methodsrnsuitable for composite materials have to be used.