Can all dynamic analysis (ex. Response Spectrum, time history, Harmonic, etc..) be performed on underwater piping correctly while using AutoPIPE?
Please see the following AutoPIPE help section:
Help > Contents> Contents Tab> Reference Information> Submerged Piping Systems> Dynamic Analysis Considerations
Suggest to start with not modeling the effect of pipe submerged in water as a first step, instead of a more complex submerged pipe modal analysis. One thought is that this would generally give higher frequencies compared to submerged pipe.
If possible calculate how much additional water mass would be attached at each point, the next step would be to insert additional weight at the points to represent hydrodynamic effect and then compare with the aforementioned simple approach to get a sense of how much difference is the water making. Then use engineering judgment and code regulation guidance to decide which results to use for design.
Model Subsea (Underwater) Piping