Fully coupled THMC-MPM published in JMPS

A fully coupled THMC-MPM framework for modeling phase transition and large deformation in methane hydrate-bearing sediment

When methane hydrate dissociates, the host sediment weakens and can fail, for example in submarine landslides; at the same time, large deformation feeds back on the hydrate reaction. Capturing both the pre- and post-failure stages has been difficult.

We present a fully coupled THMC material point method with a six-field formulation that includes the Kim–Bishnoi kinetic model for hydrate reaction, a strain-softening Mohr–Coulomb model with hydrate-dependent strength, and a hybrid explicit-implicit time integration scheme for efficiency.

The results show that shear dilation creates negative pore pressure that triggers local dissociation, that shear heating during rapid deformation accelerates dissociation and softening, and that strength loss, temperature changes and slope geometry together drive retrogressive failure.