A Total Lagrangian Smooth Particle Hydrodynamics Approach for Modelling of Soft Granular Powders

Most food items, pharmaceutical powders, and biological cells can be classified as soft particle systems. They are commonly characterized by substantial inter-particle contact and significant elastic or plastic deformations within the particles. Simulating large deformations and complex contact properties of high-density granular materials remains a challenge. To accurately model such systems, we propose an efficient numerical approach employing Total Lagrangian Smooth Particle Hydrodynamics (TL-SPH). TL-SPH is integrated with the hourglass control technique to effectively model plastic deformation within an individual particle. Concurrently, a penalty stiffness method, taking into account the contact direction at each surface point, is used to compute contact forces between particles. This contact algorithm accurately models bothfrictional and cohesive contacts commonly observed in various particle systems. The accuracy of the proposed approach is validated on its predictions of elastic and plastic deformation, friction, and cohesive contact. It is further applied to simulating the uniaxial compression of a 3D soft powder packing to examine the microscopic and mesoscopic mechanical properties during the compaction process, where a frictional, cohesive contact model is employed to describe the formation of cohesive bonds and solid bridges over the contact surface between two powder grains. The computational efficiency is further enhanced by Compute Unified Device Architecture (CUDA)-based GPU parallel computing.