SINGLE-ANGLE COMPRESSION MEMBERS LOADED THROUGH ONE LEG

摘要

Tests on single angles loaded through one leg show that the dominant displacements occur in the plane perpendicular to the connected leg, i.e. bending occurs about an axis parallel to the connected leg. Torsion had little effect on the performance. One angles with connection bolts tightened by the turn-of-nut method gave the same ultimate load as that for a similar angle with bolts that were snug tight. The research showed that beam-column type design methods were complex and they gave very conservative results. Column-type design methods were much better. However, they had difficulty predicting the strength of the unequal leg angles because they use the minor principal axis in their procedures. A new method (Eqs. 6a and 6b) based on the ASCE approach used for angles in steel towers was developed that is satisfactory for both equal and unequal leg angles. It is recommended that this new method replace the current AISC-LRFD method, which is unduly complicated and conservative.