topic Re: Seismic weight calculation error in Robot Structural Analysis Forum

Seismic weight calculation error

mgaafar — Fri, 07 Sep 2018 00:07:34 GMT

Hi,

attached a multi-story building. I noticed that the self-weight used in the seismic calculation is different to what the load case of self-weight and I don't know why.

Self-weight Case Total vertical load = 95,549 kN

Effective Seismic Weight = 8,244,740 kG = 82,447 kN

Any thought why this is happening?

Seismic weight calculation error

mgaafar — Fri, 07 Sep 2018 00:07:29 GMT

Hi,

attached a multi-story building. I noticed that the self-weight used in the seismic calculation is different to what the load case of self-weight and I don't know why.

Self-weight Case Total vertical load = 95,549 kN

Effective Seismic Weight = 8,244,740 kG = 82,447 kN

Any thought why this is happening?

Re: Seismic weight calculation error

Artur.Kosakowski — Fri, 07 Sep 2018 09:10:56 GMT

Hi @mgaafar

The weight of curtain walls is disregarded in the equivalent lateral force method. You can either convert them to meshed panels or define self weight for curtain wall (cladding) panels in a separate load case and convert it to masses.

If I managed to answer your question(s) press the Accept as Solution button please. This will help other users to find solution(s) much faster. Thank you.

Re: Seismic weight calculation error

mgaafar — Mon, 10 Sep 2018 16:14:38 GMT

May I Suggest that a warning message that show up stating that the cladding weight is not accounted for when calculating the effective seismic weight so users are aware of this.

Re: Seismic weight calculation error

Artur.Kosakowski — Tue, 11 Sep 2018 08:37:51 GMT

Hi @mgaafar

I'd rather have it included. I have already asked the development team if this could be done.

Re: Seismic weight calculation error

mgaafar — Tue, 11 Sep 2018 17:07:11 GMT

Artur, I agree as well that it should be included in the Selfweight same as all other elements, but if not then at least a warning message should be introduced to warn the user.

Re: Seismic weight calculation error

Artur.Kosakowski — Wed, 12 Sep 2018 08:02:19 GMT

Hi @mgaafar

At this stage we have to wait for the development team decision on this matter. I'll update this topic when I have any new information.