Failure criterion for nonreinforced and reinforced thermoplastics
Can you suggest failure criteria for conventional and reinforced (short fibre) thermoplastics?
I would like to simulate, in mesoscale, the initial, and ultimate failure of reinforced thermoplastic composites with matrix material such as PEEK, PSU or PEI.
The most accurate failure condition depend on specifics of the thermoplastic, for example ductility, free volume, and the fiber matrix interface.
I have experienced great accuracy using the critical chain stretch conditions (which is discussed in one of my papers). For highly ductile polymers Mises stress can also work well (see Christensens book). Other times switching to a fracture mechanics approach works better.