• spectral analysis

    I am analyzing a tower of 16 levels using a spectral dynamic analysis, I read about the correction of missing mass and I understand the theory, my question is, how it integrates the analysis and to what extent it is valid to consider this?, I have obtained…
  • RE: Modes

    In RAM Structural System, Ram Frame, use Loads - Load Cases - and add a Dynamic - Eigensolution load case. More here: RAM Frame - Dynamic Modal Analysis FAQ In Ram Elements it's one of the options in Process - Analyze. More here: RAM Elements Dynamic…
  • 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 concept modal mass in Vibration analysis

    Unfortunately, while we are calculating the modal mass (mass participation) of each vibration mode they are not stored or exposed to the user currently. I added an enhancement request (#494917) to make those values available.
  • 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…
  • RE: RAM Frame Response Spectrum Base Shears

    It's all correct what you said. Use the base shear at the end of the report only when the base is the ground. You also have the right idea regarding I/R and scale factors. I don't usually bother with a separate case for drift unless I get to a point where…
  • RAM Elements: Mass of members for modal analysis

    Hello, I am using RAM Elements (V8i, release 13.3.0.117) to model an industrial steel building with long-span roof trusses and perimeter braced frames. I will be running a dynamic response spectrum analysis. For the gravity load case I have a self-weight…
  • RE: Rhythmic Excitation of Monumental Stairs in RAM Elements

    The response spectrum (acceleration and time data) is irrelevant if you only want the natural frequencies, but in Ram Elements something must be entered for the dynamic analysis to run. Depending on what you enter for the rsp, the scale factor and the…
  • Dynamic analysis in Staadpro

    I am doing a dynamic analysis for a 10-storey RC structure in a seismic prone region, using Staadpro. I have entered the spectrum data in metric, so scaled by 9.81, and utilised 1.0 times the self-weight, in the global X, Y, and Z directions. I have no…
  • Re: Multiple Direction Time History Analysis in Staad.Pro V8i

    I am also having the same problem. When i apply three time varying load on a single node in a single direction with time laps between them, then staad pro only gives results for the last time varying load applied to the node. so plz if someone is aware…
  • Re: time history and p-delta in staadpro

    You need to be very careful when dealing with p-delta with dynamic analysis in staadpro. I remember a post where I mentioned that p-delta with dynamic analysis has been implemented by other programs like Etabs, Sap and Midas for a long time but staadpro…