RESEARCH ON DISTRIBUTED COHESIVE ELEMENT METHOD

The research significance, theory foundation and some advances of a distributited cohesive element method, as a new numerical method, is reported briefly. By releasing the rigid cohesive constraint of conventional finite element methods, the continuum is discretized as an augmented system consisting of bulk elements and distributed cohesive elements. Based on a generalized sub-region mixed variational principle, the generalized sub-region mixed potential functional of the augmented system and the governing equations of the distributed cohesive element method are derived. Considering the inertia effect during dynamic fracture, the equation of motion for the distributed cohesive element method is derived, based on linear momentum balance. To establish a discrete constitutive model, a multi-Bond Atmosphere Superposition (BAS) model is proposed. By combining EAM and BAS, a multiscale Embedded Atom Hyperelastic (EAH) model is established and it is the closed-form solution for nanoscale stress calculation. Two numerical examples are presented to demonstrate the capacity of the distributed cohesive element method in an arbitrary crack propagation simulation.