Load Dependence of Dynamic Viscoelasticity of Epoxy Resin and its Composites

The load dependences of dynamic viscoelasticity of casting novolac epoxy 648 and its composites, reinforced by glass fiber (GFRP) or carbon fiber (CFRP), were investigated by dynamic mechanical thermal analysis under high loads. The fiber property and load pattern were considered to analyze the complicated variations in storage modulus and loss tangent with the change of loads. The load effects are comprehensively addressed by a phenomenological theory about suppression effect of static load on the motion of microstructure units, combined with the influence of shear stress and interface properties between fiber and resin.