Reponse Spectrum Solvers

[Motorspirit]

Hi

I have been using a response spectrum solver on a particular problem for seismic base acceleration analysis. While I am satisfied that the model is giving me the correct structural displacements and hence member loads I am curious as to the solver output text.

For each mode of vibration the output gives:
-The output from the user input response spectrum table (based on the modal period) (I get this bit)

- An "Excitation"

- An "Amplitude"

Is "excitation" the the ratio of the structures displacement versus the forcing displacement(or the base displacement to cause the acceleration)??

What is the amplitude a measure of?? It does seem to correspond to any of the modal results.

I don't use this sort of solver much but am curious to know what these outputs are. Im using the FEA package Strand 7.

Thanks

 

[jhardy1]

Definition of the meaning and derivation of the Excitation Factors can be found in the Strand7 On-Line Help file (and the hard-copy Theory Manual, if yuo have acess to a copy) - check out the Help section on "Solvers | Spectral Response | Log File".

Hope this helps!