Hi VanHa
Caesar will solve the problem as you model.
You can build caesar model as linear or as non linear.
If you
1)remove friction
2)do not use any gap in support
3)always use both directional ( + & -) support

then your caesar model become linear if you ignore material non linearity as Mr Anindya already give a nice explanation.

In Practical aspect we commonly use non linear system. It is the same reason why we do not check occasional stress directly like this
W+P1+F1( Occ) rather than collect only occasional effect then add that with sustain to check occasional stress.

Regards

Habib