Fillet welds subjected to impact loading – an experimental study

Abstract

Virtually no studies in the open literature are concerned with the behaviour of fillet welds under impulsive loading, which may occur due to actions such as explosions and impact. We therefore developed a novel test setup allowing for measurements of the force and the deformation of fillet welds subjected to impact load conditions. The test specimens had either longitudinally or transversely oriented fillet welds, and they consisted of structural steel. Furthermore, the test specimens were designed so that plastic deformation and failure predominantly occurred in the fillet welds. In addition to the impact tests, corresponding quasi-static tests were performed for comparison. The results showed that the resistance was practically unaffected by the applied displacement rate for both types of specimens. Thus, existing formulas for estimating the resistance of fillet welds that are based on quasi-static behaviour may also be employed for severe impulsive load cases. The deformation capacity of the transverse specimens appeared unaffected by the displacement rate as well. However, the deformation capacity of the longitudinal specimens was significantly reduced for the impact load case. Images of fractured welds recorded with microscopes displayed that the welds experienced stronger localization of deformation for this load case than during quasi-static loading. This enhanced localization was probably induced by self-heating and corresponding thermal softening of the weld material.