Ultimate tensile deformation and strength capacities of bolted-angle connections

• Experimental test of 31 double-angle bolted-connections under pure tension
• Rupture of angle and rupture of tension bolt were the common failure modes.
• The U.S. method for prying action of bolts is unconservative for bolted-angles.
• Combined load effect was accounted for in the analysis of prying action of bolts.
• New equations for ultimate deformation and strength capacities were proposed.

This paper reports an experimental study of 31 bolted double-angle connections under a pure tension load. Failure modes such as angle rupture and bolt tension rupture were observed. The test results included load versus deformation curve, ultimate tensile deformation and strength. A new equation for predicting axial deformation capacity was proposed based on a regression analysis. The merits of a frame model and a truss model were investigated in predicting the ultimate tensile strength of the tested connections. A component-based model was then proposed to predict the load versus deformation curve of the connection. It was found that the current AISC equation on the prying action of bolts seriously underestimate the prying force of bolts when used with angles. A new prying equation was thus proposed for the design of bolts to ensure that the ductility of bolted-angle connections would be achieved.