Thermal stresses

Temperature rates cause fictitious thermal strain rates

$$- \alpha \dot{T} \delta_{ij} \;\;\; {\rm where} \;\;\; \d... ...; {\rm if} \;\;\; i=j \;\;\; {\rm else} \;\;\; \delta_{ij}=0$$

where $\alpha$ is the group_materi_expansion_linear coefficient and $\dot{T}$ is the condif_temperature. These fictitious thermal strain rates in turn lead to stress rates.