Experimental study of a full-scale multiplanar tubular XT-joint

This paper reports on a fill-scale test of a multiplanar,sr tubular XT-joint conducted using the multiplanar ultimate strength test rig at the Nanyang: Technological University. The XT-joint is made up of a chord with a pair of out-of-plane braces and a single in-plane brace welded to the chord. The geometric parameters for this joint are alpha (2L/D)=21.86, beta (d/D)=0.6, gamma (D/2T) = 24.07 and tau (t/T) = 0.98. A constant axial tension load was applied to the out-of-plane braces and an axial compression load was applied to the inplane brace and increased until failure. This specimen failed by plastification of the chord wall under the compression brace and through cracks at the weld toes of the tension braces. The ultimate axial compression load was significantly reduced by the tension load in the out-of-plane braces when compared to a corresponding uniplanar T-joint.