The thermal stress equation is defined as the stress caused in any body due to differences in temperature or by thermal expansion. In other words, the thermal stress is created when a change in size or volume is constrained due to a change in temperature. Thermal stress can be destructive as the forces and the pressure created due to thermal stress are large. Below given the thermal stress formula for calculating the thermal stress of any mechanical object.
Thermal stress equation is based on Young's Modulus and strain. You can easily find the stress due to temperature expansion using the above thermal stress formula.