Coefficient of Thermal expansion | Instantaneous vs mean 1

[shiraz883]

Hi,

Table TE of ASME Section II part D lists the thermal expansion coefficients for materials. COlumn A of table TE represents instantaneous coefiicient of thermal expansion whereas column B represents mean coefficient of thermal expansion.

Which one is to be used in elastic analysis for evaluation of thermal stresses 'Q'?

Thanks


Shiraz
Sr. Engineer
Haldor Topsoe