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Using the variables u and v in the function describing applied force

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We’re working on a Mechanics problem where we would like to use the variables u, v, w, (displacements in x, y, and z) in the description of applied force. This is an iterative problem--as v decreases, the force increases, until it reaches either a steady state solution, or a "Snap"--the problem runs away, meaning v continuously increases and never converges on a point. We were able to put v in the force formula. It seemed like COMSOL accepted the variable. And initially we thought that the solver was actually doing the iterations for us. But further investigation made us question this hypothesis. Can you please shed some light on this question? Attached is a screenshot showing our setup.

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Khurram Tai


1 Reply Last Post 15 ago 2022, 04:39 GMT-4
Henrik Sönnerlind COMSOL Employee

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Posted: 2 years ago 15 ago 2022, 04:39 GMT-4

This looks like a correct type of expression for the force. It will generate a nonlinear formulation. The study step as such should, of course, also be geometrically nonlinear.

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Henrik Sönnerlind
COMSOL
This looks like a correct type of expression for the force. It will generate a nonlinear formulation. The study step as such should, of course, also be geometrically nonlinear.

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