Rate-dependent thermal behavior of fillet welds subjected to various load angles

Abstract

The objective of this paper is to investigate the rate-dependent thermal behavior of fillet welds in welded lap joints subjected to different load angles. Performance of welds in fire is complex due to unexpected induced forces that are developed due to different fire-time exposures. To address this issue, an experimental program is performed to examine the rate-dependent behavior of fillet welds for three different welded lap joint configurations under steady-state thermal conditions. The lap joints are classified as longitudinal, inclined, and transverse where the angle between the axis of the fillet weld and the direction of the applied load is 0°, 45°, and 90°, respectively. Two displacement loading rates are used: 1.5 mm/min (fast) and 0.1 mm/min (slow). Retention factors for the weld material under different displacement loading rates and angles are presented and compared with those available in the literature. The results show that the effect of displacement loading rate is significant for temperatures larger than 400 °C and become severely significant at temperatures larger than 500 °C. The effect of the slow displacement loading rate (0.1 mm/min) at 700 °C reaches around 40%, 37%, and 29% decrease in strength capacities for transverse, inclined, and longitudinal welded lap joints, respectively.