This is cross-posted from the FEMAP_misc forum. I am hoping to generate some additional thoughts on the question. Thanks, Dave P.
Many of our components are injection molded from PA66 with 40% glass fiber reinforcement. Based on some research (some a few years ago and some just today) I think that reinforced polymers like the one mentioned exhibit brittle failure mechanics. If this is true, then one implication is that a ductile failure criterion, such as von Mises stress, is not appropriate.
Is there anyone here with experience running FE simulations of components molded from fiber reinforced engineered thermoplastics who would comment on the best stress to use? It may be different dependant upon the temperature considered or the amount of moisturization of the component, etc. Maybe there are some textbook, internet or other engineering resources that someone could direct me to.