Anisotropic Damping Behaviour of Thermoplastic Composites

As stiff and light fibre reinforced composites tend to high sound emission, the damping properties are essential for the entire structural and acoustic engineering. Viscous damping is a common and reasonably linear model of the damping behaviour, but here is depending on the fibre orientation, such as elastic and thermal material properties, too. ADAMS and BACON developed a model for unidirectional fibre reinforced plastics (frp) based on the classical laminate theory starting in 1973. The approach includes three damping coefficients - for longitudinal damping in fibre direction, damping transversal to the fibres and shear based dissipation. The damping of a laminate then is accumulated layer wise including the anisotropic stiffness. So far, the model has been applied mainly to thermoset matrix materials. The paper summarises the parameter estimation for different thermoplastic frp with angle ply and cross ply set up and shows possibilities and limits of the ADAMS/BACON damping criterion.