Hello,
I'm trying to better understand the workings of the solid mechanics module, and I came across an apparent discrepancy between the documentation and the module itself.
The momentum balance equation in the module itself (Solid Mechanics -> Equation) for a stationary solution is:
,
but according to the documentation, the correct equation is:
.
I feel like I must be missing something simple here. Does the solver assume that the strain is small, and therefore 
? Or is there maybe one of the gradients in terms of the materials frame and one is not?
Cheers, Adam