Hi mul211,
Once the load and frequency are determined how far from the pump discharge nozzle should the piping be included in the Harmonic modeler?
It depends on the magnitude of forces in pipe segments far from source or origin. Note that, low range shaking force may cause high cycle fatigue.
Also how is the stress computed compared to a B31.3 stress allowable? I don't see a place in the load case combinations to do this. Is it a manual calc where you add Sustained and OCC dynamic?
See page 5-41 of Technical Reference Manual.
dynamic equation of motion: (K - Mw^2) A = Fo
This is exactly the same form of the equation as is solved for all linear (static) piping problems. The appealing thing about this is that the solution time for each excitation frequency takes only as long as a single static solution, and, when there is no phase relationship to the loading, the results give the maximum dynamic responses directly.
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