Response Spectrum Software

Question

Response Spectrum Software

macan1 (Structural)

(OP)

12 Nov 04 18:57

I would like to know if there is software program to modify the damping of Response Spectrum function.
Example: change damping from 5% to 10%.

tomirvine (Mechanical) · Answer 1 · 2004-11-16 12:11:02

I do not know of program.

This calculation could be done indirectly, however.

First, synthesize a time history to satisfy the response spectrum for the specified Q value.

Second, calculate the response spectrum from the time history using the new Q value.

Tom Irvine
www.vibrationdata.com

Zhuge (Structural) · Answer 2 · 2004-12-07 01:41:34

every code usually describes how they formulate the Response spectrum (can be based on ductility or damping). Try to read through the commentary, hopefully you get the formula.
If you know the standard earthquake records used in seismic design for you area, you may use SPECTRA ( part of ruaumoko).

PEStructural (Structural) · Answer 3 · 2004-12-07 05:20:54

The following website outlines Newmark and Hall's method of changing between damping ratios:

http://peer.berkeley.edu/~jrodgers/index.htm?c227top.htm&227cont.htm&ElResp/elresp5.htm

All you do is take your 5% damped acceleration and multiply it by the ratio of 1.2/1.39 (per the table on the website) to get the 10% damped acceleration.

If you click on the next arrow at the bottom of the page "six" times, there is a good example of what I'm talking about.

Hope this helps,

Mike

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