Our work on MPM for handling extremely large finite rotation/deformation for micropolar continua with evolving contacts has been accepted by CMAME

Ran Ma and I have our latest work on finite deformation/microrotation MPM for micropolar materials accepted by CMAME before the winter break. There is a great body of work which proves that material point method (MPM) is a great tool to simulate extremely large deformation (even for Lagrangian granular flow). The potential of MPM to handle simulations with large rotation (metal forming, torsional wave...etc) and large micro-rotation for micropolar materials (e.g. sand, meta-materials), is less explored. In this work, we introduce a numerical framework that includes the necessary ingredients, include the explicit time integrator, the Lie-group projections between grid and material points, and a micropolar frictional models for the contact mechanics. Consequentially, the model enables us to introduce a unified approach to simulate dynamic responses of both solid and fluids that exhibit size effects. 

To the best of our knowledge, this is the first research successfully enable the simulations of micropolar continuua in MPM in the geometrical nonlinear regime.  Preprint available [URL]