Experimental tests on fillet and PJP welds in CHS moment T-connections

Abstract

An experimental program was developed at Dalhousie University to test various unreinforced circular hollow section (CHS)-to-CHS 90° T-connections subjected to branch in-plane bending moment with the objective of determining the effective section properties of the welded joints. Eleven specimens were designed to be weld-critical (i.e., to fail by weld rupture), and tested by applying a single quasi-static point load, laterally, to the top of each branch. An equation for the weld effective section modulus for CHS-to-CHS moment T-connections is developed, and various design formulae are assessed through a first-order reliability method analysis. The scope of this research covers fillet and partial-joint-penetration groove welded connections with 0.31 ≤ branch-to-chord width ratio ≤ 0.91, 31 ≤ chord wall slenderness ≤ 46, and 0.75 ≤ branch-to-chord thickness ratio ≤ 1.00. Recommendations are made for weld design using the “effective length approach” in AISC 360.