The American Iron and Steel Institute (AISI) has published a research report introducing new design methods for three limit states of cold-formed steel clip angles: shear, compression, and pull-over of the screw connections. Details of the testing and results are included in “RP15-2: Load-Bearing Clip Angle Design.” A free download is available here (58 pages).

The research was conducted by Cheng Yu, Ph.D., associate professor at the University of North Texas, and his team. The scope of the project was to investigate the behavior of load-bearing cold-formed steel clip angles, and develop appropriate design methods for their use when subjected to three different loading conditions. For each limit state, a test program was conducted to investigate the behavior, strength and deflection of the clip angles.

The test results were then compared with existing design methods for members similar to, but not exactly the same as, cold-formed steel clip angles. The research team developed new design methods for each of the three limit states studied in the project. LRFD (Load and Resistance Factor Design) and LSD (Limit State Design) resistance factors and ASD (Allowable Strength Design) safety factors were provided to apply to the proposed design equations for nominal strength.

“This comprehensive research is significant because it provides a method for designers and

specifiers to more accurately predict the strength of cold-formed steel clip angles,” said Jay Larson, P.E., F.ASCE, managing director at Construction Technical Program. “We appreciate the detailed work and new design methods developed by Dr. Yu and his team, which will advance cold-formed steel design practices in the marketplace.”