Dear folks,
I have to continue the work of my team, while checking his load case scenarios, I found these:

L4:W+T1+P+H (OPE) note: T1>T2>T3>T4
L5:W+T2+P+H (OPE)
L6:W+T3+P+H (OPE)
L7:W+T4+P+H (OPE)

L8:W+P1+H (SUS)

L36:L4-L8 (EXP) (ALG)
L37:L5-L8 (EXP) (ALG)
L38:L6-L8 (EXP) (ALG)
L39:L7-L8 (EXP) (ALG)

L40:L36,L37,L38,L39 (EXP) (SIGN MAX)
L41:L36,L37,L38,L40 (EXP) (SIGN MIN)

L42:L40-L41 (EXP) (ALG)



My question is:
As noted above that T1 is the highest temperature. Simply thought we can assume that the biggest expansion stress must come from T1, then why to use load case no 42 (L42: L40-L41 SIGN MAX – SIGN MIN) in order to get the biggest expansion stress?
Do think it would be easier to analyze from the highest temperature (T1) only, then I don’t have to put the rest of temperatures (T2,T3,T4)?
Please enlighten me