I'm in need of a solution when working on FEA for a spaceframe chassis. The issue is with the frame wherever there are either beams too small or they are perpendicular to eachother like show in the following images that don't want to mesh at all, just disappear. Most of my model will mesh without issue and run, just parts of it disappear. I have tried a combine on the parts that are highlighted in blue but they still seem to give issues when meshing by disappearing. Any info is much appreciated!

http://imageshack.us/photo/my-images/198/fcqk.jpg/

http://imageshack.us/photo/my-images/707/9f2u.png/