Problem in Tower 7

[Jordan_Chemshirow]

Good afternoon
I have one question, in the following files, I attach one model of simple steel construction, once made in the program mode "stages of construction" and once made in ordinary stage, summary two files. The problem is in front column (view X_1 and view B_1), more precisely in the support of this column. Independently the support of this front column is different in the model, where I use program mode "stages of construction", and program displays support in right way in the stages- in first only R1,R2,R3 in second R1,R2,R3,M1,M2,M3 .
Entrance information is same for both models, but results are different?
The reactions in first model in stage 2 is reaction R3=0,87kN;R1=2,52kN, without moment and in stage 1 the results are same, why?
But in second model where I have only one stage, the reactions is true (R3=0,87kN,bigger reaction R1=3,20kN and moment M2=2,05kN.m)
Results are from load case 11

Code: Izaberi sve

http://dox.bg/files/dw?a=e85f4d9e4a

Code: Izaberi sve

http://dox.bg/files/dw?a=54e3ac0e97

Version Tower 7.0 build 7203
eng.J.Chemshirow
K-enginering LTD
Best regards
Thank you

[b.milan]

The answer is logical.
In model with staged construction in stage 1, You reached the equilibrium without having moments at the support.

In stage 2 You just simple fixed the support without any change of the load. Imagine that You poured concrete around the column in some existing construction. It is obvious that even after concrete become stiff, concerning the forces and influences - nothing will change in the rest of the construction.

BUT - if You later change the load, this construction will start behave differently - those fixture of support will start working and You will get moments in reactions.

In model without stages, equilibrium was initially established on the system with support suppressing rotation and You get the forces appropriate for this statical system.

In staged analysis - history matters and that is the point.