Controlling Fundamental Building Period
I am running the seismic analysis for a 3 story structure and have questions about how to determine the appropriate building period to use for the seismic analysis.
Gravity system is typical steel frame, with composite slab/framing at 2nd and 3rd Floors…
RAM Frame Dynamic Analysis Criteria
When performing a dynamic analysis for Response Spectrum in Ram Frame, is it correct to check the reduced stiffness for steel members in the criteria? I have a situation where I need to scale up my dynamic loads to achieve the 0.85*ELF forces. The question…
RAM Mass Participation with Ritz Vectors
Hello,
I have been trying to use the Ritz vector solution to get 90% mass participation in my model. I have noticed something I find odd, but perhaps this there is a rational explanation for this. Running 30 eigenvalue modes the mass participation in…
RAM SS Merging Nodal Loads
Hello,
I have a three story building with a rigid diaphragm on levels 2 and 3 (level 1 is ground). My roof is a metal deck and I want to analyze it as flexible.
I created my Nodal load cases labeled Roof-X and Roof-Y, both Seismic Load type.
I need…
RE: Determine Building Period with Ram Elements and/or Ram Structural System
Both programs do it. Our Dynamic analysis FAQs should get you started:
RAM Elements Dynamic Modal Analysis FAQ
RAM Frame - Dynamic Modal Analysis FAQ
RE: RAM SS - Response Spectrum Analysis according to AS1170.4
Regarding the scale factor, what we usually tell people to do is scale the dynamic load by Ie/ R, then check the base shear and compare to the lower bound limit of .85* ELF approach, and re-scale if the dyn result is too low.
communities.bentley.com…