Novel measuring approach for damage of viscoelastic material (Part I): Constitutive model

In order to describe the mechanical behaviors of viscoelastic material more accurately, the effect of damage on the constitutive model of viscoelastic material is necessary to be considered. The basis of building viscoelastic constitutive model with growing damage is to develop all kinds of measuring methods for damage, and then to obtain the damage evolution equation. Based on LEMAITRE-CHABOCHE's damage model and the elasticity recovery correspondence principle, a novel measuring approach for damage of viscoelastic material was developed. In this approach, the recovered elastic stresses or strains in loading and unloading were obtained using the elasticity recovery correspondence principle, then the instantaneous elastic responses were gained, and a set of damage values were achieved by applying LEMAITRE-CHABOCHE's damage model, the damage evolution equation and the constitutive model with damage were deduced finally. The measuring approach for damage is suitable not only for the case of axial tension, but also for the case of fatigue.