Qing Zhong's Communities Activities

Effective Length Method

John Rodrigues — Thu, 20 Apr 2023 15:46:03 GMT

I am analyzing this braced frame structure with the effective length method following this procedure https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/55456/asce-7-aisc-360-and-the-effective-length-method-in-the-ram-structural-system

The drift report seems to indicate that my structure is extremely torsionally irregular. The stability coefficients report also shows that it exceeds the max allowable.

Before I begin adding new braced frames to my structure, is there a way to determine that the issues shown in the reports are accurate and not related to mistakes in modeling the structure?

RAM Frame -- story displacement

Qing Zhong — Fri, 07 Apr 2023 15:51:05 GMT

1. We have a semi-rigid diaphragm and it is modeled as sloped. There is large displacement in one direction. The roof slope is actually low : at 1/2" to 12" slope. Shall we just model it as flat roof?

2. What is the best way to get displacement at different story level? at certain notes?

3. Is there FAQ on nodal displacement, story displacement and drift?

Thanks,

Jane

RAM Frame -- Story displacement

Qing Zhong — Tue, 04 Apr 2023 20:53:34 GMT

The story displacement along Y direction is huge and along X direction is normal. The nodal displacements are normal for both x and y direction. What cause the hugh difference?

Thanks,

Janecommunities.bentley.com/.../VPECTRL3-_2D00_-RAM-Frame-_2D00_-Nodal-Displacements.pdf communities.bentley.com/.../VPECTRL3-_2D00_-RAM-Frame-_2D00_-Story-Displacements.pdf

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Fri, 03 Mar 2023 00:09:08 GMT

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Two independent structures in one RAM model

Qing Zhong — Fri, 03 Mar 2023 14:34:56 GMT

I have a long building with a seismic isolation joint in the middle. Can RAM structural system model two independent structures in one model -- lateral loads are separately distributed over the two LFRS? The two structures share one strip footing at the interface. Two separate diamphragm will be used. Thanks