Numerical Investigation of Fillet Welds in HSS-to-Rigid End-Plate Connections

Abstract

This paper presents a finite element (FE) investigation on the behavior of fillet-welded hollow structural section (HSS) rigid end-plate connections, wherein the entire weld length is effective. The FE models are validated by comparison to 33 experimental tests and a parametric study is then performed with 73 numerical tests to evaluate the effect of weld size, HSS branch wall slenderness and branch inclination angle, on fillet weld strength. The inherent problem with one-sided fillet welds to a tension-loaded element is illustrated. A reliability analysis determined that the directional strengthincrease factor for fillet welds in North America leads to inadequate values of the safety index for joints to both circular and rectangular HSS, especially for connections with large welds. Hence, an alternative yet safe method for estimating the strength of fillet welds to HSS, based on weld size, is proposed. An expression for the fillet weld size required to develop the yield strength of a 90° HSS branch member is derived.