why in solid mechanics module there not a option for a no rotation boundary load

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currently I have a model, for the cube I want it to have a no rotation constaint on it, However there is no option for a no rotation boundary load is there a workaround for this type of problem? I uploaded the mph file and the image of the cube where i want a no rotation boundary load



2 Replies Last Post 2024年3月25日 GMT+1 16:56
Edgar J. Kaiser Certified Consultant

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Posted: 5 months ago 2024年3月23日 GMT+1 14:29
Updated: 5 months ago 2024年3月23日 GMT+1 14:30

In a stationary mechanical setup you need to suppress rigid body movement to get an unambiguous solution. That means you suppress all 6 DOF, translations and rotations.

You only want to suppress rotations and still allow translations. I think the system is underdefined this way and the solver would not converge, even if you found a formal way to do that.

Second, what real physical arrangement would be constrained this way? It seems to be unphysical to me.

Maybe you want to analyze your problem again in order to see if the constraints you need can be achieved in a more realistic way.

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Edgar J. Kaiser
emPhys Physical Technology
www.emphys.com
In a stationary mechanical setup you need to suppress rigid body movement to get an unambiguous solution. That means you suppress all 6 DOF, translations and rotations. You only want to suppress rotations and still allow translations. I think the system is underdefined this way and the solver would not converge, even if you found a formal way to do that. Second, what real physical arrangement would be constrained this way? It seems to be unphysical to me. Maybe you want to analyze your problem again in order to see if the constraints you need can be achieved in a more realistic way.

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Posted: 5 months ago 2024年3月25日 GMT+1 16:56
Updated: 5 months ago 2024年3月25日 GMT+1 17:15

In a stationary mechanical setup you need to suppress rigid body movement to get an unambiguous solution. That means you suppress all 6 DOF, translations and rotations.

You only want to suppress rotations and still allow translations. I think the system is underdefined this way and the solver would not converge, even if you found a formal way to do that.

Second, what real physical arrangement would be constrained this way? It seems to be unphysical to me.

Maybe you want to analyze your problem again in order to see if the constraints you need can be achieved in a more realistic way.

got it i take a look at my problem again and see what need to be done.

>In a stationary mechanical setup you need to suppress rigid body movement to get an unambiguous solution. That means you suppress all 6 DOF, translations and rotations. > >You only want to suppress rotations and still allow translations. I think the system is underdefined this way and the solver would not converge, even if you found a formal way to do that. > >Second, what real physical arrangement would be constrained this way? It seems to be unphysical to me. > >Maybe you want to analyze your problem again in order to see if the constraints you need can be achieved in a more realistic way. got it i take a look at my problem again and see what need to be done.

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