Insertion of an epoxy solid simulation issues

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  • Last Post 17 April 2019
clement13196 posted this 10 April 2019

 I am currently trying to simulate a fit insertion of an epoxy shape in a Chrome-Cobalt alloy notch. I have a particular shape so that the epoxy object can fit in the notch but cannot be removed from it without damaging the epoxy.

 

Here a photo to show you the model:

 

 

 

I apply a displacement of 15mm on the y-axis, corresponding to the gap between the two objects. This displacement is applied on the front-face of the epoxy solid. I fixe the notch on the external faces.

 

I chose to go for a static structural analysis because the displacement is not time-dependent, there is no velocity applied and also to reduce the time of computation. I also added frictionless contact zones, and configured it to avoid matter penetration when the epoxy solid is inserting the notch.

 

I spend a lot of time to resolve convergence issue: I am running the simulation with Ansys Student Version 19.1, so I am limited in the node/element numbering. That is why I increased the number of sub-iterations to refine the calculation.

 

My problem comes in the results part. I am a beginner in continuum mechanics, so I have trouble in the understanding of the results.

Here are the results for the maximum VM stress of the epoxy solid:

 

 How you can see in the first photo, we can see that the deformation is local on the edge of the solid as matter should compress itself when the solid is inserted in the notch. The intuition would say that the deformation can be global, and the deformation will diffuse itself through the epoxy solid and then compress the all solid. Moreover, the yield limit (54,6 MPa) is over-reached when the highest peak of stress is observed: 750 MPa.

 

Does this mean that the material will yield? I don’t have yielding data of the material to complete the material data of Ansys. Does these results can be suitable regarding the material property?

 

 Here are the results for the maximum VM stress of the notch solid:

 

 Regarding the second image, I just don’t understand how is it possible that the Chrome-Cobalt is highly stressed (15 270 MPa) despite the fact there is no stress zone in the results image.

 

For my opinion, I think these results are not accurate because of the highly stressed epoxy and alloy materials. I don’t know much about epoxies behavior, so that’s why I am requesting help here.

 

If I had a complete license, does a refinement of the mesh could allow me to get more accurate results in this particular case?

Which face should I selected to see the peak force to apply to insert the epoxy solid?

 

Do not hesitate if you need more information regarding one of my settings, or if you want to see the complete simulation by your own eyes. 

Thank you, 

Clément

 

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SandeepMedikonda posted this 13 April 2019

Turn on the Min and Max probes to identify the exact locations.

What does your contact settings look like? Insert an initial contact tool and make sure all contacts are closed. If not, increase the pinball radius.

clement13196 posted this 17 April 2019

Here are the Min and max probes: 

The initial contact tools tell me that all contact are open even if I increase the pinball radius. 

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