How to create a torque? 4

[lyvince]

Hi all. I am quite new to FEM and I am currently working on my university's final year project.
Here's my question, any advice is very much appreciated:

How to simulate a torque? The torque will be applied on a 3D deformable solid model(a cube) it is going to be a static analysis. The torque comes from a milling operation and will be simulated at the center of gravity of the model. In Abaqus CAE, there is an option for "Moment" that can be applied at a particular node, I am wondering whether this is indeed an alternative to simulate the torque mentioned above.

Thanks.

 

[brad]

A moment is not an 'alternative' to simulating a torque; it IS the torque
Torque=Moment; they are one and the same.

Short answer--if you want to simulate a torque at a single point, then apply the moment.

Longer answer--it sounds as if you are trying to apply this to a solid (continuum) element. These elements do not have rotational degrees of freedom at their nodes, so applying a torque to these will not work. The torque will be applied, but as there is no means to react said torque, this will result in singularities.
In this case, one has two options:
1) utilize beams, shells, or another connection which can carry a moment, and tie this into the solid elements;
2) apply a force-couple--a pair of equal and opposite forces which give a net zero force, but which result in the equivalent moment about this point.
Brad

 

[lyvince]

Thanks Brad.
You are right, the "moment" don't work on my model and Option 2 will work the magic for me.