Question

What is the boundary of restorable thermal expansion?

Answer 1

If so, supposing a 3D plate, just apply boundary conditions like

nsel,s,loc,x,0

d,all,ux

nsel,s,loc,y,0

d,all,uy

nsel,s,loc,z,0

d,all,uz

allsel

Then apply thermal loading and get the expansion in x, y, z direcitons

Answer 2

What is the boundary of restorable thermal expansion?

❱ For real materials thermal expansion is not actually linear across a broad temperature range. It is a useful approximation, but beware "far" from room.