Phase Scenarios in Random Vibration

[izax1]

We have a Random Vibration test Specification which consists of several Phases. This has nothing to do with phase angle of vibration, but are defined as several phases of Random Vibration testing with different levels (and hence g rms)and test duration.

How can that be analysed with FE? We have 7 different phases for each direction, and we could run 7*3 FE analyses. But how do we combine them to evaluate a total life?

 

[GregLocock]

Im limited experience you could use a fatigue life analysis program. Your FEA code may offer it as an add-on. I've heard of, and seen the output from, FLAPS.

Basically each phase will cause a certain amount of damage. As you add the damage caused by each phase eventually you'll get a total damage estimate, typically given as the number of total test cycles to failure.





Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.