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Surface to surface gluing behavior at thermal expansion

Creator
Creator

Dear all,

 

I have a problem using surface to surface glue during thermal expansion. When joining two meshes that are dissimilar I normally use surface to surface glue. But then for thermo-elastic analysis in SOL101 stresses would occur for the glued connection even when two bodies with same materials are joined.

Can anybody of you tell me which parameters I need to use in order to set a CTE value for the glue? An average of the glue between target and source side would be fine as well.

 

Thanks!

 

Best regards,

Jintin

5 REPLIES

Re: Surface to surface gluing behavior at thermal expansion

Siemens Phenom Siemens Phenom
Siemens Phenom

If you are defining glue between two solid meshed bodies that have the same isotropic material defined and you are looking at isothermal expansion, there should be no stresses induced by the glue.

Re: Surface to surface gluing behavior at thermal expansion

Creator
Creator

Hi Jim,

 

thank you for your reply. I did exactly run an analysis with same isotropic materials of two meshes but there are still stresses that are at around 6 MPa which should actually be 0. The stresses are mostly at the edge of the glued joint. I attached a picture of an easy example I did. Some solid elements are glued to shell elements and there are stresses at the edge of the joint.

What parameters did you use for BGPARM?

 

Thanks,

Jintin

 

 

Re: Surface to surface gluing behavior at thermal expansion

Siemens Phenom Siemens Phenom
Siemens Phenom

Can you post the full model. Hard to infer boundary conditions from a post contour.

Re: Surface to surface gluing behavior at thermal expansion

Creator
Creator

Hi Jim,

 

I attached a picture of the whole model. I tried to attach the dat-file but it won't let me.

Basically it is just a plate where on one side I modelled the glue with solids and on the other side I wanted to see if the surf-to-surf glue would act correctly if I attached a row of solids to the shell elements. The same material from the shell is defined for the solids. The red marked solids are the one with surf-to-surf glue.

For the boundary conditions, I have an initial temperature of 20°C and a load of -80°C on all elements. I fixed one point at the corner of the shell plate and put user defined SPCs on the other corners in order to constrain rigid body movements.

Hope that the model is clear, if you need anything more specific please tell me.

 

Thanks,

Jintin

Re: Surface to surface gluing behavior at thermal expansion

Creator
Creator

Hi Jim,

 

I just noticed in my model that the problem was not the surf-to-surf gluing but it was the RBE3 elements and stresses were coming from the glue modelled with solids. I put a CTE-Value for those elements and changed the rigid element method to lagrange multiplier. But they won't expand as the material they are attached to. How can I tell the rigid elements to expand?

 

Best regards,

Jintin