ANSYS Static Structural Analysis, Defining a Rigid Body and contacts


I have a problem in ANSYS Static Structural Analysis when there are contacting surfaces. I explained the situaition below, could you please help me?


I need to realize a static structural simulation where there are two contacting bodies as one of them is defined as rigid (brown body) and the other one is defined as deformable (yellow body) shown in the picture below.

The Force on the Circular Surface:

In the picture; the brown body is rigid and the yellow body is deformable. I apply a force in the negative x direction on the circular surface as shown in the picture. Note: This force is caused by frictional forces so the loading type is possible in reality and comprehensible.

The Displacement on Circular Surface:

I also define displacement for this circular surface as to be zero in the y and z directions and to be free in the x direction. For the contact surfaces. (Detailed note: This circular surface is actually mounted on a sliding rod, and rod moves with the yellow part)

The Contact Surfaces between brown and yellow parts:

For the contact surfaces, I tried many things but couldn't successfully define them and oobtain the results. I tried to define frictionless contact region, but I got nothing but failures because of this.

Note: When the force is applied, because of the bending trend of the yellow part, the contacting surfaces can be seperated throughout the course of analysis. So the contact surfaces which are fully in contact with the rigid body at the beginning is most probably going to be seperated.

Would you please enlight me with your wise ideas about how to do this?

Thanks for your time reading my question and your sincere thoughts, sincerely



  • HuiLiuHuiLiu Forum Coordinator

    For you yellow flexible body, it has displacement BC defined in the Y and Z directions but free in the X. The only support it gets in X is from the contact with the rigid body. When you apply a force in the X and the contact opens up, this can result in underconstrain problem in the X direction. One suggestion is to define displacement in the X to drive the yellow flexible body and read the reaction force from the BC. You can also try turn on weak spring and see if it helps to stabilize the model while it becomes under-constrained.

    Do you have the model converge for a few steps or did it not converge at all from the beginning? If you have a few steps converged, you can take a look at those steps to see how the yellow part is deforming and what happened right before it stopped converge. Also check the solve.out file for warning messages and errors, which can give you more hints on diagnose the model.

  • @mtcnonn

    I don't understand your problem.

    It seems like you have two bodies and you are separating them. In that case, there is nothing left to analyze except the acceleration of the yellow part, which you can do with a hand calculation of F = ma.

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