[MARS-UD-100] LDPM Formulation Updated for Shear Facet Failure

[weixinli]

Hello everyone,

The LDPM formulation was updated in order to simulate tests involving larger shear displacement. A shear reduction factor is introduced at the tet element level (nodal force calculation) to consider the reduction of facet area due to large shear displacement. To activate this feature, please download the correct version of MARS library (currently version 2017.02.36 under Beta folder), and compile it with MARS-UD-100. For gitlab users, you should reverse your branch to a former commit (abe1df4) in order to use the original version of mtMLdpmpUD files (before introducing reduction factor in constitutive laws). In your input file, please add ShearFacetFailure flag to activate the shear reduction feature:
TetSolidList name LDPM {
   ...
   ShearFacetFailure
   ...
}

The change hasn't applied to energy calculation. The dissipated energy calculated by MARS may not be correct now with the new formulation.

A example input file is attached.