Stabilized semi-implicit MPM published in IJNAMG

Stabilized semi-implicit material point method for hydro-mechanical coupled large deformation soil-structure interaction analyses

Coupled hydro-mechanical analysis of soil-structure interaction is prone to instability, especially when deformations become large.

This collaborative work develops a stabilized semi-implicit MPM based on an incremental fractional step approach. It removes the spurious pore-pressure oscillations seen in explicit schemes and relaxes the time-step limit imposed by low permeability. A penalty-based frictional contact algorithm reduces artificial gaps at soil-structure interfaces, and artificial compressibility, an APIC transfer scheme and a B-bar treatment further improve stability. An axisymmetric version makes classical geotechnical problems cheaper to model.

The framework is verified on a range of coupled, axisymmetric, dynamic and soil-structure interaction benchmarks with the Modified Cam-clay model.