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How to Analyze a pre-stressed structure
Posted 20 sept. 2011, 16:28 UTC−4 MEMS & Nanotechnology, MEMS & Piezoelectric Devices Version 4.2 3 Replies
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I am trying to simulate a pre-stressed structure. The structure is a plate that is pre-stressed (let's say tensile) and then attached to another structure so that its ends are clamped.
I am using the MEMS module and my first try did not give me what I wanted: I used the pre-stress parameters with fixed ends. This simulation fixed the ends before the stress is aplied so the result was a bowed plate.
My expectation is to have a flat plate that has a tension applied with fixed ends.
I was thinking of changing the boundary condition to add an external stress, but that is not really what I need to simulate since I lose my clamped edges...
Can somebody recommend an easy way of setting up this simulation?
I am fairly new to COMSOL, so please try to be descriptive with your responses...
Thank you very much in advance,
Osvaldo
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"my way" is to run two simlations in sequence, one to set up the stress in a correct way, the second to apply my additional load(s)
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Good luck
Ivar
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Can you be a little more specific on how to feed the data from the first simulation into the second one?
As I mentioned, I am not proficient in COMSOL yet.
Osvaldo
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there are different ways, depening on your model.
I your case probably you need to set up the BC to run the first statinry case to load the structure, then "store the solutions" (it's added in v4.2 automatically if you chain several solvers in sequence by adding a new solver nodse after the first default one, or you might add it in by "hand" = rightclick)
You solve this first case (right click + comute to selected), then as you need the preload to remain, while you add the next load you need to manually add a new BC node and conditions and then run the second simulation (again right click ...) But you need to ensure that the "dependent varables" sub node in the second solver sequence is pointing to the stored solution for it's initial conditions.
Another way is to have a coninuation sweep with a bolean parameter that you have defined that turn on and off some BC's (boundary conditions)
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Good luck
Ivar