ANSYS Workbench contact problem

[Anders Johnsen]

I'm currently working on my bachelor's thesis in mechanical engineering.

A part of my thesis is conducting a finite element analysis on a sump designed for sewage.

As shown on the attached picture, I've applied a preliminary point load on top of the sump-lid. As a result, the upper layer of the lid has been "pushed through" the lower part of the lid.

FYI: The load will be distributed over a contact patch at a later point in the analysis.

As this is a nonlinear analysis due to the nonlinear contacts, and due to nonlinear materials which will be added later, trying and failing takes far to long, therefore I ask for your help.

I suspect the problem is related to the contact options I've used. I've tried playing around with different combinations of contact options, without success.
Between the top and bottom surface of the lid, there is a 5 mm gap. Offsetting the contacts by 5 mm doesn't seem to solve the problem either.

How can this be solved?

 

[Anders Johnsen]

Attached, you also see how the loads distribute when the applied load is distributed on both layers of the lid. As you see, the loads are much neater distributed through the structure. This however does not give an accurate representation of the reality of the loads.

 

[L_K]

Could you post a picture of the settings of the contact in question. One thing you should do first
to ensure that the surfaces are "seeing" each other is to put more elements in that area.

 

[scheah]

Hi Anders,

Try checking the Contact Tool (RMB Connections, Insert, Contact Tool) to help troubleshoot your contacts before a solve.

I agree with L_K on the mesh density. Perhaps also try increasing the contact pinball radius.


Best regards,
Sze Kwan (Jason) Cheah