Learning Forum

[Sam Ho]

I am modelling a part which is held in place by graviy and a frictional contact. However, even after correctly assigning material and applying gravity at the first time step, Ansys still shows my entire part flying away hence leading to convergence issues. I am not sure why this is.

(Only bolt pretensions were applied and there should be no other forces acting on it that causes this)

Furthermore, is there a way for me to set a limit to the maximum displacement of a part?

 

[Sahil Sura]

Hello Sam Ho, 
Underconstraining the model might lead to convergence failure and also might be the reason for the part to fly off. 
You can specify the appropriate boundary conditions to properly constrain the model.
Understanding the Need to Fully Constrain the Model - Lesson 2 - ANSYS Innovation Courses
If in the case, the model is supposed to be underconstrained, you can take advantage of 'Weak Springs'.
The option can be accessed via the 'Analysis Settings' and you can set the value to the program-controlled or may define an appropriate value.
More on the same can be found in the following reference-
Solver Controls (ansys.com)
One or More Parts May Be Underconstrained (ansys.com)
61.8. Recommendations (ansys.com)

If you want to introduce specific constraints, joints also seem to be beneficial.  Joints (ansys.com)

Hope this helps!
Thanks,
Sahil
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