How perform a Modal transient analysis?

Hi everyBody
I have a steel frame with a steel plate in the centre, with applied a pressure load; at the exteems of frame i have 4
constrains locking DOF1 DOF2 and DOF3;
I have used beam element to create the frame and shell elements to create the plate;
I have applied a certain pressure on the shell elements, but i need a impulsive load, how can i create it?
How can i perform a transient modal analysis? witch load collectors i need to create?
Here there are three images to help you to understand.
After that i have to output the values of bending moments, shear and normal stress near a intersection of
3 beams element in the frame; then model the intersection with a 3D and apply the loads i have found from
the transient modal Analysis.
Where can i reed these kind of values concerning a node of the frame?
thank for the support
Damir
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Hi and thanks
yes Sir, i have seen it, but i don't know how to behave in my case, for example
in my model need to apply a impulsive pressure of - 0.0075 Mpa in Y direction; should i do the same thing of the
example?
-Define loadcollector DAREA
-Define constrains on plate's nodes, with DOF2 = -0.0075 and select load types >DAREA
and then define all the others collectors like in the example?
Thank you

Hi Damir,
Please go through TLOAD1 details in OptiStruct which can answer your question.
Maybe in your case you have to reference PLOADx in the TLOAD1 card.

Thank You Prakash
i'll try to sett the analysis in this way...

Hi prakash
i understand what you say me, about:
What you can do is create a set with the nodes of interest and request normal, shear stresses for that particular set.
To request specific output, goto Analysis page>> Control cards>> global output request>> Stress >> change type to SHEAR
But my frame is CBEAM elements based, so 1D mesh; is possible to output the nodal stresses in this kind of mesh?
Have you seen this tutorial in the help documentation already?
OptiStruct > OptiStruct Tutorials and Examples > Tutorials > Advanced Small Displacement Finite Element Analysis:
OS-1315: Modal Transient Dynamic Analysis of a Bracket