I find myself having to dig through the manual on dynamic analysis again and having some difficultly.

Our process group has given me a system that they are predicting will be subject to slugging (to the order of a slug moving through once per second). The client wants to know what happens if we don't add the control systems that would eliminate the slugs from forming. Thus it has come to me provide an answer.

Since I was able to get unusually good data on the prediction of the slug (density, length, velocity, etc), this looks like a perfect application for a time history analysis, as the run only has five elbow against which to apply the slug forces.

Based on the user documentation and notes from a presentation at a previous CAU that I've reffered to several times, I was able to build the time histories for the loadings at each elbow and run the analysis.

Naturally, with a cycle time of 1 Hz, this is a very high cyclic event and fatigue is my main concern. However, the user guide specifically states that FAT is not available for a time history analysis, though it is for the other dynamic analysis options. Why is this? Right now, Caesar is telling me that it "passes" by comparing it to the OCC stress allowable.

I'm currently digging through Section 8 Div 2 to compute the cycle life based on the stresses predicted by my time history analysis.