You can do this either way. If you want to perform a time history analysis, then you follow option 1 above. If you want to simulate the fluid hammer in a Force Spectrum Analysis, you follow option 2.
Both methods are acceptable, however:
- Time History requires you to be more precise with the input data.
- Time History allows you to walk the pulse down the system.
- Time History takes longer to run
- The Force Spectrum is performed in the frequency domain, therefore there is no sense of time or phasing.
- You can only look at the pulse in one location per load case, so if you want to walk the pulse down the system, each leg must be a different load case.
- The results from the Force Spectrum run should be conservative when compared to the Time History run.
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Regards,
Richard Ay - Consultant