Stiffness changes with temperature under compression
I am modeling a gasket that is initially being compressed in a threaded joint at room temperature and then undergoes a thermal change to -40 deg C. I have created an FEA model to simulate this and extract the reaction forces and contact pressures generated by the gasket at the two temps. I am also accounting for some gasket shrinkage during the thermal change with a thermal expansion/contraction coefficient. In the model, the reaction forces increase dramatically after the step change to -40 deg C. The thermal contraction effect seems to be minor and completely dwarfed by the increase in stiffness at -40 C. I understand the model is predicting these results because I am telling it to use stiffer material properties at -40 C, but what Im struggling with is if this phenomenon is really physical. Does it make sense that the reaction force would increase in a compressed gland 2-3X just due to temperature change?