WRC 071

This report discusses the test results of three welded structural joints of two-dimensional truss joints built from steel tubes. The three connections were designed with three different joint-eccentricities between the resultant of the web-member forces and the axial chord-member force. Also the results of tensile tests on four single tubes with welded transverse joints are reported herein. The joints, each made up of a chord member, a vertical web member, and a 45 degree diagonal web member, were placed in a specially designed loading frame. A direct tensile force was applied to the diagonal member by means of a 400,000 lb. hydraulic testing machine. Under this loading condition, the strains from about 60 strain gauges were read for each of these specimens. Also, the crack patterns of the stress coat applied to these joints were studied for information on the stress trajectories. The tensile test results on the single tubes gave information about the weld and tube strength. Some interesting convulsions were derived regarding the effect of joint eccentricity on the ultimate failure load for the type of joint tested.