Zero length contact 3D elements

[Kamesh9]

Hi all

I am trying to use zero length contact 3D element in my bridge model. When I perform eigen analysis, i get near zero values, both positive and negative. I have tried replacing the contact elements by elastic elements in directions 1,2 and 3, and the eigen values are perfect in this case. I have checked the direction of contact elements and also the master and slave nodes, i guess they are correct. It would be very helpful if someone can give insight on as to why this is happening.

Thanks

Kamesh

[Kamesh9]

Problem solved.

[vesna]

Kamesh, it would be good if you say how you solved it in case someone encounters a similar problem.

[Kamesh9]

Initially, I was doing eigen analysis before analyzing the model for gravity loads, so the contact were not getting activated and the bridge deck was in rigid body motion. I figured this out and did the gravity analysis first, but still the eigen values were negative. I had to try different values for the penalty parameter and finally one set of parameter worked.

[vesna]

Thanks for sharing!