Seismic analysis of pipe

[nukeboy]

Ok, im going to start of saying that i am very new to the program. (as in i just got thrown on my first ansys project this week, and have extremely limited knowledge of the coding) Also, im running V.11.

Im running a seismic analysis on a pipe. The pipe is modeled using PIPE20 elements. I have an input of a time history of acceleration (consisting of 2000 or so accelerations with a time step of 0.01 s. I was able to create a successful array of accelerations (dont know if this is the best way to do this) but when i go to analyze both stresses and strains there is no data there. I also tried ramping up the accelerations by a very large amount but it did not effect the lack of results.

So i guess my ultimate questions are (1), is there an easier/more proper way to input an acceleration time history, and (2), once the solution runs with the acceleration data, how do i go about getting the stress/strain values so that i can ultimately get the strain rate?

 

[MJCronin]

nukeboy....

Explain the reason that you are using ANSYS for time-history analysis on a piping system.

There are other USNRC Certified, piping-oriented software programs that will perform time-history anaysis on piping systems, calculate stresses and compare them against piping code allowables. (CAESAR-II for example)

Why ANSYS for this workscope ?

 

[Drej]

Maybe our friend is undertaking non-linear analysis (given he/she's using PIPE20 "plastic" elements) and hence he/she needs to use non-linear FE to account for plasticity. If this is the case then standard coding allowables (stress based ie linear) wouldn't be appropriate, and neither would the use of CAESAR in that case (presuming CAESAR cannot handle non-linear strains and transient fully integrated dynamic analysis).

To answer the OP question, search the site for keywords such as "non-linear" "time history" transient" and "seismic" (for example). There is lots of info on how best to undertake non-linear transient analysis in ANSYS on the site.

Cheers.


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