Ultimate Load Tests on Braced Multi-Story Frames

Four tests were conducted to ultimate load on three-story, two bay fully welded frames fabricated from ASTM A36 steel. The frames were full size and were proportioned by the plastic design methods. Gravity, checkerboard and lateral loads were applied to the frames up to failure. The frames were braced against sidesway by diagonal bracing. The tests were conducted to study the behavior and strength of braced multistory steel frames and to evaluate plastic design methods for predicting frame behavior at maximum load. Theory is compared with experimental behavior in both the elastic and inelastic range. The experimental ultimate load reached or exceeded the maximum load predicted by plastic theory with an average discrepancy of 4%. The tests indicate that plastic design methods can be applied to braced multistory frames.