Hellow All,
I have been using simulation reguarly to model isotropic carbon composite sheets and it works spelndidly but in doing so I am always appling loads to the face of the shell. Now I am trying to model a condition where I have a carbon composite sheet and I have a bolt going through it. I am concerned about tear out and trying to specify wall thickeness. As a results the loads are now plane with the face and applied to the hole edge, bearing loads. The results I am getting are far off the mark. I have also tried builing an aseembly and apply loads to solid bolts with a no pentration condition between the shell and the bolts but that does not seem to work either. Any suggestions?
I think I know why you are in the ditch. It sounds like you are using the surfaces from solid bodies for a shell mesh. You need to know all about the secret decoder ring if you are going to use such an approach. Just make a SURFACE and apply the composite shell and loads. It should work fine. If you use solids, you need to ensure that the edge you pick is a surface - otherwise it won't fall on the extracted shell, hence no deformation. I would strongly advise you never use solid surfaces to extract shells. Just use the surfacing tools to make the surfaces and then delete the solid bodies. Your encounter frequency with grief will go way down.
You don't need the work around. Just try the above. The work around may have issues with the bonded contacts. Try a bending case and see if looks just like the same case using one shell.
Here are some images to prove the point that it works. The laminate is for some made up material 0.080" thick - 8 ply, 60 msi x 350 ksi, 0,90, +45,-45 symmetric.