Time dependent response of a rubber-toughened carbon/epoxy composite with damage accumulation

Polymeric composites are frequently modeled as linear elastic materials. However, matrix-dominated properties, such as transverse and shear modulus, can display significant nonlinear time-dependence, especially under conditions of high stress and aggressive environment. This behavior is primarily due to the viscoelastic nature of the polymeric matrix. In addition, polymeric composites also present time-dependent damage growth. In this work, nonlinear viscoelastic constitutive equations were used to represent the time-dependent behavior of a rubber-toughened carbon/epoxy composite during damage...