[krudra]

Hello everyone,
I recently downloaded and installed solids4foam and have been able to run a few of the tutorial cases successfully. I was going through the implementation for the large deformation solvers (like nonLinGeomUpdatedLagSolid.C), while simultaneously going through the theory described in "An open-source finite volume toolbox for solid mechanics and fluid-solid interaction simulations" by Cardiff et. al.


Everything seems to be making sense, except for the implementation of the stress divergence term in equations 20 and 21 which uses Nanson's formula. In the reference (as well as a bunch of other papers citing Nanson's formula), the stress divergence term is
j * (f_inverse)_transpose * normal * ,


whereas in the source code (nonLinGeom*.C), the term implemented is
j * (f_inverse) * normal,
i.e. the transpose seems to be missing? I'm not sure what I'm missing here. Please let me know if anyone has an explanation for this.

[krudra]

I've attached eqns 20 and 21 from the reference, along with the source code. The stress divergence term implementation is at line 179, with the corresponding j and f definitions at lines 211, 217.