Fatigue Testing and Analysis of Flare Bevel Groove-Welded Aluminum Joints for Pedestrian Bridge Applications

Abstract

Flare bevel groove (FBG) welds are used in truss bridges with square hollow structural section (HSS) members. To reduce costs, joints can be welded without bevelling, but this negatively impacts the fatigue performance of the connection. This approach is often used in pedestrian bridges made from steel or aluminum. To investigate the fatigue performance of FBG welds, a study was conducted on T-joints made from aluminum square HSS members. The goal was to establish an S–N curve for these welds and present a numerical fatigue life prediction methodology. The study involved cyclic tests supplemented by a fatigue life prediction using linear elastic fracture mechanics (LEFM) coupled with finite element (FE) analysis using the software ABAQUS. Several parameters were varied, including the HSS section size and the corner radius (as extruded and hand ground). Six identical samples were tested for each combination of parameters to generate an S–N curve. The paper ends by drawing conclusions regarding the fatigue performance of aluminum FBG welds and their suitability for use in cyclically loaded structures such as pedestrian bridges.

Keywords

• fatigue
• flare bevel groove welds
• hollow structural sections
• aluminum
• linear elastic fracture mechanics
• finite element analysis