Good morning,
I’m having a problem with a contact gear+shaft. After having defined everything correctly, the execution ends with an error. The problem is in the contact beacuse when I don’t use it, but a “compound geometry”, the solver doesn’t give any error.
By running it in Abaqus, it fails beacuse of Negative volumes in the surface contact, but changing the contact into a sliding one, in ends without errors.
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How can I solve that problem in PrePoMax?
Thank you.
UPDATE: I solved it by increasing the min element mesh to 1mm. But why now does it works?
As I understand, you are getting the “Job failed - no results exist” error. You are using tied contact so you could try with tie constraint as well. Regardless of the type of interaction, make sure that adjustment is enabled and proper tolerance is specified (not too large though - this may cause errors like negative volume in Abaqus). Is there a reason why you don’t want to use compound geometry ? This would simulate bonded connection like tied contact or tie constraint but more efficiently.
I would also try with prescribed rotation instead of torque. And, to eliminate RBMs, fix all the DOFs of that RP, apart from the rotation about the shaft’s axis.
If you simplify the geometry a bit, you could make use of cyclic symmetry.
I got the same problem by using tie constraint. I didn’t use the compound geometry beacuse I wanted to analyse stresses in the contact zone.
How can I define rotation instead of torque?
Sorry, what RBM and RP stand for?
Thank you
For that you may need the default nonlinear contact, it allows you to check the contact pressure and shear stresses since this form of contact permits relative motion of the surfaces in both normal and tangential directions. However, it will be much more challenging in terms of convergence so it’s better to start from tied contact or tie constraints and proceed to standard contact if they are working fine.
Apply a Displacement/Rotation boundary condition to the reference point and specify the angle of prescribed rotation as UR2 (rotation about Y axis). This aids convergence and helps eliminate RBMs (explanation below).
RBMs stand for rigid body motions. They are not allowed in static analyses and may appear if the model is underconstrained.
RP means reference point (used for rigid body constraint).
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Thank you, I will try it.