I am doing simulation with shell elements. Shells are created on the midsurfaces. This results in gap between the surfaces which would otherwise have been coincident with solid models. While running the analysis I give bonded contact between the surfaces(with the gap). However I get an error saying that the model does not have enough restraints. It is as if the bonded contacts are not created at all. Are the bonded contacts created if there is a gap of about 0.5" between the surfaces. Is there a setting where I can set the distance for bonded contact detection. Any info on this is greatly appreciated.