Peridynamic modeling of bonded-lap joints with viscoelastic adhesives in the presence of finite deformation

This study concerns damage initiation and its progression in bonded-lap joints with adhesives under quasi-static loading conditions. The weak form of peridynamic (PD) equilibrium equation is derived based on the nonlinear response of elastic adherends and viscoelastic adhesives. The peridynamic deformation gradient tensor is evaluated in the bond-associated domain of interaction using the PD differential operator. The fidelity of this approach is established in the absence of failure by comparison with benchmark solutions for relaxation and creep response under simple loading conditions. Subsequently, the PD predictions in a domain of two dissimilar elastic and viscoelastic materials are verified against the finite element predictions. Finally, a double-lap and a single-lap joint are considered for failure initiation and growth. The PD predictions successfully capture the deformation response and damage initiation sites and propagation paths.