I have jest started my first braced frame structure under the 97 UBC.
Section 2220.127.116.11 limits the width to thickness ratio of angles to 52/Fy^1/2.
This puts the minimum thickness of a 6 in. angle at 3/4 inch. Under the 94 UBC
Table B5.1 the width to thickness ratio was 76/Fy^1/2. The 94 UBC would allow a
6 in. angle to be 1/2 in. thick. I would like to know of any reports of
failures and/or testing which brought about this change. Most of my structures
are not buildings and I could use section 2213.8.3. However there size and cost
makes it desirable for these structures to go through a major earthquake with
out following down or needing major rework.