If you select two adjacent beams at a time
Edit>Reshape>Intersect
when you have gone and around and done all of them this way then they will clean up as you wish.
I started withe the one on the left and bottom and did INTERSECT
Then the bottom beam and the one on the right INTERSECT
the one on the right and the one on the top INTERSECT
and lastly the beam on the top and the left INTERSECT
Erika
Architect, Consultant
MacBook Pro Retina, 15-inch Yosemite 2.8 GHz Intel Core i7 16 GB 1600 MHz DDR3
Mac OSX 10.11.1
AC5-18
Onuma System
"Implementing Successful Building Information Modeling"