Response Simulation Analysis Restraints and Enforced Motion Location

[struclearner]

I am trying to do a Response Dynamics/Simulation on an exhaust pipe.
I am very new to this type of dynamic analysis.
I constrained the pipe where it is flanged to engine manifold, in all six directions and the other side of the pipe, an RBE element is created and the independent node of the RBE is selected for an enforced displacement location in a certain direction.
The model is first run for Modal Analysis using SOL 103 Response Dynamics, but I am not getting the right mode shapes and corresponding frequencies.
All the modes shapes are of RBE elements on each end, the pipe structure is showing any mode shapes.
The examples and tutorials, I have gone for learning so far, I see the restraints and enforced motion location applied at the same location/node.
Is there any way, to simulate the scenario, I am trying to simulate, exhaust pipe fixed at one end and being excited on the other end.
If on the enforced motion location all the other degrees of freedom are restrained but one which will be used for Enforced Motion location will give the correct mode shapes to use later in Response Simulation analysis.

Thanks a lot for help and reference to material/literature.

 

[JBlack68]

what the frequency of these RBE elements on each end? Close to zero?
There is an example of a beam attached at 1 one and an exciting force at the other end

 

[dfreire]

Hello,

If you could upload the model, it would be easier to look for an explanation. Are you using RBE2 or RBE3?