Peridynamic simulation of creep deformation and damage

This study presents a nonordinary state-based (NOSB) peridynamic (PD) modeling of creep deformation and damage. The force density vectors in PD equilibrium equations are derived by considering the Liu and Murakami creep model with a damage parameter. The bond-associated (BA) deformation gradient is derived by using the PD differential operator (PDDO). Traction and displacement boundary conditions are directly imposed through a novel strategy while solving for the strong form of PD equilibrium equations. The PD form of traction components enables the imposition of traction conditions in the actual “boundary layer” region without any unphysical displacement kinks near the boundaries. The approach is validated under uniaxial and 2D plane stress assumptions by considering creep deformation due to constant stress at high temperatures. The creep strain predictions are in excellent agreement with the experimental data and analytical solutions. Subsequently, creep crack growth in a compact tension (CT) specimen is simulated by using the damage variable in Liu and Murakami constitutive model.