Hybrid lattice particle modelling approach for polymeric materials subject to high strain rate loads

Hybrid Lattice Particle modelling (HLPM) is an innovative particular dynamics approach that is established based on a combination of the particle modelling (PM) technique together with the conventional lattice modelling (LM) theory. It is developed for the purpose of simulating the dynamic fragmentation of solids under high strain rate loadings at macroscales with a varying Poissons ratio. HLPM is conceptually illustrated by fully dynamic particles (or "quasi-particles") placed at the nodes of a lattice network without explicitly considering their geometric size. The interaction potentials among the particles can employ either linear (quadratic) or nonlinear (Leonard-Jones or strain rate dependent polynomial) type as the axial/angular linkage. The defined spring constants are then mapped into lattice system, which are in turn matched with the material's continuum-level elastic moduli, strength, Poissons ratio and mass density. As an accurate dynamic fracture solver of materials, HLPM has its unique advantages over the other numerical techniques which are mainly characterized as easy preparation of inputs, high computation efficiency, ability of post-fracture simulation and a multiscale model, etc., This paper is to review the successful HLPM studies of dynamic fragmentation of polymeric materials with good accuracy. Polymeric materials, including nylon 6-6, vinyl ester and epoxy, are accounted for under the loading conditions of tension, indentation and punctuation. In addition, HLPM of wave propagation and wave induced fracture study is also reviewed.