Dear All,
I hope you are doing well and safe.
I have a beam fixed from one end and experiencing a harmonic displacement excitation as: y (t) = A sin (wt) [Figure 1 is attached]. As peer the software manual, what I have understood is that; in the frequency domain study, all I need to put as an input to the software, is the amplitude only. For example, if I want to run harmonic Force/Velocity/Displacement/Acceleration, I just need to give the software the amplitude part of the equation only.
However, when I try to run the simulation under Prescribed Displacement given an amplitude of[ - 3 cm], the results are not reasonable at all: 1. the results at all frequencies are constant, 2. I should see a peak at the resonant frequency, but there is no peak which means there is something wrong [Figure 2 is attached]. On the other hand, when I put a force excitation given the amplitude only, the results are reasonable and correct.
It is perfectly working with force excitation, but not with any of prescribed Velocity/Displacement/Acceleration.
May I know where I went wrong? And why the results are not correct as am treating the prescribed displacement excitation as force excitation.
Many Thanks, Islam