Bonded contacts between solid bodies (or not)

The problem isn't with the no penetration surfaces, it's with the bonded surfaces which aren't bonding. I've tried compatible and incompatible meshes and bonding non touching faces together even though I've been very careful to make sure they are touching.

Thanks Bill but that's not quite what I was modelling. Note that my vertical surfaces don't extend right the way through the depth of the beams.

Also the crack extends as far as the boundary between the two bodies in both the top and bottom halves of the beam. I did it this way so I can I can generate a densely meshed volume into which the crack penetrates but I limit the depth of the volume in order to keep the densely meshed volumes to a minimum.

Anyway! I've found out what the issue is. When I selected the three solid bodies of each beam to be bonded I selected all three at once, in effect saying "bodies A, B and C are bonded together". That doesn't work. I need to select pairs of bodies, in other words "Bond body A to body B, body C to body A and finally body C to body B".

Now I get a sensible result, almost.

However, looking carefully at the crack tip I can see fresh air where there shouldn't be any! Having thought carefully about it though, I think it must just be a graphics issue. If the two surfaces weren't joined then the top beam wouldn't be pulling the bottom beam out of shape so I'll take this as a result!