Re-examination of double-angle knife shear connections

This paper reports an experimental test of 18 double-angle knife shear connections. Each specimen was monotonically loaded to failure under a combined shear load and rotation. In addition to the anticipated failure mode of rupture of welds, rupture of angles was also commonly observed. It is found that the strength of Welds B can be determined accurately by the instantaneous center of rotation method when the shear load eccentricity in the plane of the welds is taken as one-half of the leg width. The load eccentricity is not dependent on welding procedure. The test results reveal that the current U.S. design method for Welds B is extremely conservative. The failure mode of the rupture of the angles always occurred at the top of the angles along the edge of the welds. This failure is due to the combined action of connection rotation and shear load.

► Experimental test of 18 double-angle knife shear connections
► Rupture of welds and rupture of angles were the common failure modes.
► The shear load eccentricity in the plane of the welds was one-half of the leg width.
► The current U.S. design method for knife connections is extremely conservative.
► Angle rupture was due to the combined action of connection rotation and shear load.