incorrect stresses

Question:

Hello. We have received incorrect values of the stresses «Sig-P1», «Sig-P2», «Sig-P3», «Max-Shear», «Sig-EFF», «Sig-OCT» (Load combination «sum». The model is attached). You will find detailing document attached this mail. 


Regards, 


Answer:




Hello,

The difference in result is due to the way in which the stresses are obtained.  For the envelop load case, the stresses are simply envelop of the combinations within, while for an addition load case, the Sig-XX to Sig-XZ values are obtained by adding and the other values are obtained by using the formations for the respective component.
Now, Sum is an Add type load combination.  So, max of enw(CB) and sw(ST) are added to obtain Sig-XX to Sig-XZ and remaining components are obtained by using the formulations.
Whereas, SWenv is a load combination of Envelop type.  In this case, all the values tabulated are nothing but envelop (max or min) of the load cases or combination that are a part of this combination.
Going by engineering sense, it won't be right to create a combination like Sum as it will give results different than what is expected.  SWenv is the right way to go.  Also, rather than creating 1+sw and 2+sw as a load case, its better to use combinations there.  This will save analysis time for a big model.
Kindly let us know if further assistance would be required.

Regards,
Nandeep
Technical Manager, MIDAS


Thank you for answer!

I have no more questions.
Creation date: 10/17/2018 10:53 PM (dklee@midasit.com)      Updated: 10/18/2018 8:23 AM (dklee@midasit.com)
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