Strength of duplex stainless steel fillet welded connections

Abstract

Standard uniaxial tests were conducted on round bar specimens made of stainless steel and the corresponding weld metal. The stress-strain curves of both base metal and the corresponding weld metal were obtained. The constitutive relationship for base metal and the corresponding weld metal were calibrated against the test results and were taken into consideration for further finite element analysis on stainless steel fillet welded connections. Six transverse fillet welded connections and five longitudinal fillet welded connections were tested to investigate the strength, deformation, and fracture angle of stainless steel fillet weld connections. According to the test results, the average angle of stainless steel transverse fillet weld was 29°; the average angle of stainless steel longitudinal fillet weld connection was 46°. The ultimate strength for a transverse fillet weld connection was 1.5 times than that of a longitudinal fillet weld. Relevant numerical models using ANSYS were calibrated against experimental results. Further parametric studies were conducted to investigate the effect of weld length and weld size on the strength of stainless steel fillet welded connections. Finally, both the experimental and numerical results were compared with the current design provisions. The conservatism of the European, American, and Chinese design codes was discussed. A revised prediction of fillet weld strength was proposed based on the strength of the longitudinal fillet weld strength.