Shock Response Spectrum - Is there a workaround?

[Disla]

@JuanP74

Try first with a very simple model

That’s a good advice.

@Tim

Do you know of a procedure using a number of linear dynamic base motion analyses that may be used in combination as a workaround, to achieve the same resulting displacement and stress result for a given SRS curve?

There is the clasical aproach in which result is assumed to be a linear combination of single modes individual responses + an apropiate load combination (SSRS). The aim is to translate the dinamic problem to the equivalent static.Check this tutorial.

Seismic Analysis of Multi-Story Buildings using the Response Spectrum Method

@Tim

The initial normal modes analyse requires all natural frequencies across the frequency range of the SRS.

Not really. A few modes such that Modal Mass Ratio >90% should be enough according to regulation. ccx modal analysis provide those values.

You could try the method with ccx to see if there is any unexpected drawback. I recall trying once but equations did’, t work in dynamic, imposed displacements in beams were not reliable and reaction forces on fixed bases where incorrect at that time so I gave up. There is an applied example in the video but not all the parameters are provided (Stiffness and dimensions ). I will give it a second try.