Teddy dat is attahced:

1.dat (1.2 KB)

A beam that is fixed at both ends and has two different Nonlinear Temperature profiles (**NLTP**) on it.

The positive NLTP is as below:

LET#T_H 10 0

LET#Z_H 0 0.5[m]

The negative NLTP is as below:

LET#T_C -10 0

LET#Z_C 0 0.5[m]

The negative NLTP has the temperature value that opposite to that of positive NLTP.

I did the analysis by Sofistik 2022-2 and Lusas 19.

The beam has a rectangular cross section. If the height, **H <= 1m**, the result from Sofistik is correct, the axial force and moment due to negative NLTP are opposite to those due to positive NLTP.

The results from Sofistik are the same as those from Lusas.

The moment in **positive** NLTP, **H=1m**

Sofistik = 287.5, the unit is kN*m

Lusas = 287.5, show positve moment in negative value, the unit is N*m

The moment in **negative** NLTP, **H=1m**

Sofistik = -287.5

Lusas = -287.5, show negative moment in positive value, the unit is N*m

If the height, **H > 1m**, the result from Sofistik is **WEIRD** to me, the axial force and moment due to negative NLTP are much larger than those due to positive NLTP.

The moment in **positive** NLTP, **H=1.1m**

Sofistik = 330.6, the unit is kN*m

Lusas = 330.6, show positve moment in negative value, the unit is N*m

The moment in **negative** NLTP, **H=1.1m**,

Sofistik = **-795.6**

Lusas = -330.6

**Conclusion:**

**If H>1m, the results from Sofistik under negative nonlinear temperature profile are questionable.**