reduce memory usage of nucleation model implementation in raccoon

[BoZeng1997]

Two nucleation models for phase-field fracture are memory consuming. Either in how the material object is coded, or how the model is implemented in input deck level (or both).

source code

https://github.com/BoZeng1997/raccoon/blob/c24df81ba4ef97f1b3490821daa631d961e3e68d/src/materials/KLRNucleationMicroForce.C https://github.com/BoZeng1997/raccoon/blob/c24df81ba4ef97f1b3490821daa631d961e3e68d/include/materials/KLRNucleationMicroForce.h

how the model is implemented

https://github.com/BoZeng1997/raccoon/tree/c24df81ba4ef97f1b3490821daa631d961e3e68d/tutorials/surfing_boundary_problem The current implementation is for sure not the best way. It requires dispx dispy dispz to be transfered to the subapp. Then the subapp would compute stress tensor invariant I1 and J2. One way to improve it a little bit is by computing I1 and J2 in the mainapp then transfer it to subapp. I am waiting to see if there is even better way of improvement.