Continuum Model for Viscoelasticity, Damage, and Permanent Deformation withApplication to Swirl-Mat Polymeric Composites

摘要

A comprehensive thermodynamic framework is proposed for modeling the behavior ofpolymeric composites exhibiting viscoelasticity, damage and permanent deformation. In the present formulation, the total strain is decomposed into viscoelastic and permanent components. The effect of damage on the constitutive behavior is introduced through direct coupling between damage and the internal state variables representing deformation of the undamaged (virgin) material. This approach accounts for time-dependent damage as well as damage-induced changes in material symmetry. The viscoelastic part of the proposed constitutive model is first formulated for a general case of damage coupled with nonlinear viscoelasticity, and subsequently specialized to coupling with linear viscoelasticity. Permanent deformations are discussed in view of recent experimental findings. Finally, the proposed constitutive model is applied to experimental data for swirl-mat polymeric composites.