What happens to a body's stress if the temperature goes up or down?

[armin11]

What happens to a body's stress if the temperature goes up or down?What are the equations?

 

[Mapes]

Can you be a little more specific? What makes you think anything happens to a body's stress?

(A temperature change generally leads to a change in size; is this what you mean?)

 

[armin11]

Our university professor told us that there are some equations for temperature stress that apply to a body.for example if we restrict 2 ends of a rod and heat it up,rod grows in size but there isn't any room for it to grow so there is temperature stress.What are the equations for these kinds of temperature stress?

 

[Mapes]

This is correct. When a bar is loaded uniaxially, the axial strain is \epsilon=\sigma/E. Add thermal strain and you have \epsilon=\sigma/E+\alpha\Delta T. Take into account that \epsilon=0 when the bar is fixed, and you can calculate the stress due to the constraint.