Improved collision handling of elastic solids in sph using a contact force model

Modeling of collision between elastic solids involves deformation of bodies and the interaction with other bodies. Classically, smoothed particle hydrodynamics (SPH) is used for both, but, this does not allow one to incorporate friction and also subjects the solids to unphysical interaction when the bodies are nearby but not in actual contact. In the current work, we incorporate an efficient contact force model into a variant of updated-Lagrangian SPH to model the interaction between elastic solids. This approach models friction as well as eliminates the spurious interaction between nearby bodies. The current model is validated with several numerical examples, involving collision between two and multiple elastic solids, with and without friction. These results compare well with finite element modeling, analytical, and experimental studies. The model is easy to incorporate in any updated-Lagrangian SPH scheme. We provide a fully open-source implementation along with a reproducible manuscript.