Constitutive modeling of damage-induced stress softening in electro-magneto-viscoelastic materials

This work presents a continuum physics-based constitutive model for a damaged electro-magneto-viscoelastic (EMV) material class. An extended theory of electro-magneto-viscoelasticity is employed by incorporating the balance laws of micro-forces for continuum damage in physical and material space. Multiplicative decomposition of the deformation gradient tensor into elastic and viscous parts is incorporated to characterize the rheological behavior of EMV materials. The incorporated deformation gradient decomposition enables the intermediate configuration to set up the evolution equation of EMV deformation. The overall stress is disintegrated into equilibrium stress and viscosity-induced overstresses in the proposed modeling framework. In addition, an alternative invariant-based damage function is introduced to incorporate the damage-induced stress softening into the proposed model. The findings of the model agree well with the existing experimental results. At last, the present study successfully enables the damage-induced stress softening in electro-magneto-viscoelasticity with the least material parameters.