UBC97 Earthquake Analysis 1

[dawn836]

Hi all
I am new to Earthquake Analysis using Response Spectrum Analysis according to UBC97 so does anyone knows a link to online pdf document or web page that has brief description for this point.
Thanks in Advance

 

[PEStructural]

I'm not sure of any website but I'd be happy to answer any questions you might have about using a response spectrum.

 

[Drej]

Brief Description
Response = response; Spectrum = range of frequencies. A Response Spectrum is a plot of the maximum responses (acceleration, velocity, or displacement) of idealised single-degree-of-freedom oscillators (tuned to specific frequencies) as a function of the natural frequencies of the oscillators for a given damping value. The spectrum will be representative of a particular DOF. The response spectrum is calculated for a specified vibratory motion input at the oscillators' supports, and is characteristic of a specific time history. The subsequent spectrum is often broadened and peaked in order to "clean" it up (remove noise in the data). This spectrum is then used and applied to the mode shape(s) of the structure, accounting for participating mass in each direction (participating mass and mode shapes being obtained from the modal analysis). For each direction, the subsequent modal response (up to a specified frequency) is then combined in some manner dependent on the code used, the application and the response of the structure itself (CQC, 100-40-40, DDAM to name a few combination methods). Then each directional response is combined using another combination method, usually SRSS, to give the complete condition for the response: a single answer, which assumes that all of the modes are considered to be active. This is conservative (but not impossible). It is also a linear based analysis (linear materials, geometry, etc.), widely used and accepted in the nuclear industry.

Clear as mud?


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