Contact elements

[buggles]

Hi,
I'm trying to simulate a bolted joint using contact elements in a larger model so I'm trying to model a single bolt independently to begin with.

I've created the joint structure using volumes and meshed the contact and target surfaces using TARGE170 and CONTA174 respectively.

The normals of the elements are correct and the contact is initially 'closed'.

Unfortunately, the model is coming back saying it's 'underconstrained' upon solving.

Can anyone help?

 

[buggles]

I answered it myself, well thanks to the friction post I read from 'stringmaker'.

I overcomplicated things by putting a co-efficient of friction into my model.