Maximum values in timber design

[Anonymous]

Good morning everybody.

I have a trouble in timber design since the values taken by robot for the member verification are not the maximum values even if in the options I select to verify the member for the maximum values of every force.

I attached the file: for member 68 the maximum value of My is 29,71 KNm but in the timber design Robot uses 21,97 KNm, how can I solve this trouble?

Thank you in advance

[Artur.Kosakowski]

Hi @Anonymous

Is it the right model? The instability reported during calculations cause the results to be none for seismic analysis and doubtful for other load cases.I think you should block RX in the definitions of the releases.

When this issue is addresses and you still have the same issue with the timber design - could you attach the screen capture showing the situation you described so that it is easier to investigate it?

[Anonymous]

Thank you for your answer! I blocked Rx in the releases so that I don't have any more instability; the model results for My are almost the same. 

If I try with timber design the problem still remains as in the pictures. 

I also attached the file with the new releases

[Artur.Kosakowski · Accepted solution]

Hi @Anonymous

Robot checks both combinations 12/30 and 13/30 and the stress value (bending moment ) is correctly found for each of them but as the timber resistance depends on the components of the combination (kmod coefficient) the resistance for the one with bending moment increases too which results in the smaller ratio. You may check it if you convert these components into manual combinations and run verification for each of them separately.

If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.