Viscoelastic Properties of SMC Composites

The subject of the viscoelastic response of SMC type composites is discussed. Examples are presented illustrating the influence of material composition on the dynamic mechanical shear moduli, G′ and G″, and tan σ =G″/G′. The concept of time/temperature superposition is applied to the dynamic mechanical data and master curves constructed. Torque retention problems on bolt attached SMC components are shown to be associated with the viscoelastic behavior of the materials.