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Using Measured Damping as Input to Mechanical Abaqus Model

Using Measured Damping as Input to Mechanical Abaqus Model

Using Measured Damping as Input to Mechanical Abaqus Model

(OP)
Good morning everyone. I was hoping I could get some help using damping in Abaqus.

A little background is appropriate first I assume. I have a fairly basic model. It's a cantilever beam enclosed in a box frame. The entire system is excited at the base using a shaker, which causes the beam to bend in it's first bending mode. I drive the system at it's resonance frequency. I am able to obtain Q values by comparing the measured tip acceleration to to base acceleration, and subsequently, get my zeta value.

I am using a modal dynamics - steady state analysis to pull out accelerations as a function of frequency.

Currently, I am using the Composite Damping in the Dynamics step and have it defined as:
Start Mode: 1
End Mode: 1
Damping: my zeta value

This approach, however, does not yield a perfect correlation between the Abaqus-predicted tip acceleration and the experimentally measured acceleration. My advisors and I expect the comparison to be exact since we are using the measured damping in the model.


Can anyone tell me if I input the damping correctly, or have any ideas as to what I should do?


Thank you!

RE: Using Measured Damping as Input to Mechanical Abaqus Model

(OP)
Whoops, I have to make an edit. I am using the Direct Damping option in the Modal Dynamics step.

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