Learning Forum

[1617836513]

I'm doing a torsional performance test on a screw, and I want to limit the deformation of the drive body and apply a remote displacement to the outside of it, and finally use the remote displacement as a boundary condition to output a counter moment. Setting the body as a rigid body will conflict with the boundary condition of remote displacement. How should I set it up to realize the "using plane elements to define the rigid surface of the screwdriver" in the orange part of Fig. 2? 

 

[Ashish Khemka]

Hello,

Please see if the following thread helps: Defining rigid body and contact (ansys.com)

Regards,

Ashish Khemka

[1617836513]

 

Hi, I know how to set the part as a rigid body. But after I set the drive part as rigid body, I have the following problem:
   The drive part is not fully meshed, why is that?
   I want to add a distal displacement to the surface of the drive part that rotates around the Z axis, which will conflict with the constraints of the rigid body.

I want to achieve something like figure 3 and 4.

[1617836513]

On top of that, when setting the drive component as a rigid body, it still has such a large deformation, why is that?

[Ashish Khemka]

Hi,

Is the driver part a rigid body? Genereally mesh is generated for surfaces on rigid body which are in contact. Turn off the weak spring. You can specify rotation on the rigid body via remote displacment.

Regards,

Ashish Khemka

 

[1617836513]

Yes, it's rigid. As you said, I turned off the weak springs, but the problem persists.
What should I do to fix it, please.

[Ashish Khemka]

Above is a warning message, please check if the results look fine even with the above message.

Regards,

Ashish Khemka

[1617836513]

Hi, I don't think this answer makes sense, why would the drive part, being a rigid body, also deform?

[Ashish Khemka]

 

Hi, I was not talking about the deformation but about the warning message. The deformation results you shared is that only for rigid body? Please comment.

Regards,

Ashish Khemka

 

[1617836513]

Yes, I only set the driver as a rigid body and this is the result of its total deformation.

 

[Ashish Khemka]

[1617836513]

Hi, 

As you said, I set up the driver as a rigid body and created a remote point using its six sides. 

After that, I added a 0.1rad remote displacement of the Z-axis at the distal point, as shown in figure one. The bottom of the screw was fixed as shown in Fig. 2 and set frictionless.

The profile of the geometry is shown in Fig. 3.

Figure 4 shows the equivalent mises stress of the screw.

Figure 5 is a diagram of the total deformation of the drive section.

Figure 6 shows the value of the counter moment at the remote point.

 The same material properties are used for the transmission part and the screw as shown in Fig. 7, E is 45 GPa, v is 0.3.

 

I feel that this result is a little bit not reasonable:

The driver, being a rigid body, produces a non-negligible deformation.

The values of the equivalent force of the screw and the counter moment at the remote displacement seem to be too large. But I don't know where the problem is.

.

 

 

[1617836513]

Also I think the stress peak should occur on the inner surface, not the outer surface, is that correct?

 

[Ashish Khemka]

Hi,

For the peak support I think the mesh is not converged and may be refining mesh will change the location. Otherwise without having a look at the model it would be difficult to comment. If you have access to support then please raise a case. Ansys employees cannot download the model from forum. Meanwhile please wiat for other members to comment.

Regards,

Ashish Khemka

[1617836513]

Can you tell me how to raise a case? thanks.