Hello,

I am having confusion with respect temperatures which I need to select for an analysis. Do I have to consider the Minimum Design Temperature for stress analysis or is it enough to take only installation temperature (21degC).

My temperatures conditions are

T1: 84 DegC (max design)
T2: 0 DegC (minimum Design)
T3: 52 DegC (operating temp)

or the below conditions are ok?

T1: 84 DegC (max design)
T2: 21 DegC (Installation temp)
T3: 52 DegC (operating temp)

When I change temperature T2 from 0 to 21 Deg, expansion case stress ratio reduces drastically (from 92% to 7%).

My opinion is that minimum design temperature is for selecting the material so that it doesn't experience the brittle fracture. And upto 21 DegC there is no thermal expansion so we do not need to consider the 0 (zero) DegC for stress analysis.

Many thanks