Assume we have an impeller mounted on a shaft. When performing Experimental Modal Analysis (EMA)on this structure, do we want to perform the EMA:
1. on the free impeller-shaft body (by hanging it on a soft rope)? or
2. on the impeller-shaft body sitting in its own bearing?
Obviously, in option 2 we have restricted movement of the shaft, in 3 orthogonal directions(not rotation) but only at the bearings.
Is this motion restriction an advantage or disadvantage? After all in option 2 we'll perform the test at conditions identical to that in operation.
Thanks
1. on the free impeller-shaft body (by hanging it on a soft rope)? or
2. on the impeller-shaft body sitting in its own bearing?
Obviously, in option 2 we have restricted movement of the shaft, in 3 orthogonal directions(not rotation) but only at the bearings.
Is this motion restriction an advantage or disadvantage? After all in option 2 we'll perform the test at conditions identical to that in operation.
Thanks