Fatigue Behavior of Butt Welded Joints Containing Inclined Lack-of-Penetration

Abstract

In order to study fatigue behavior of welded joints including weld defects with certain angles to the applied stress, butt welded specimens containing lack-of-penetration inclined at angles of 0, 15 and 30 degrees to the direction perpendicular to the applied stress were fatigue-tested. The observations of fracture surfaces indicate that the fatigue crack propagates on the same plane as the inclined lack-of-penetration until it appears at the surfaces of the specimen, and then the through-thickness crack tends to propagate perpendicularly to the applied stress. The comparison of test results indicates that change in the fatigue life is little, despite the different inclined angles of 0, 15 and 30 degrees.

The multiaxial weld root fatigue of butt welded joints subjected to uniaxial loading

“…Partially penetrated double‐sided and ground butt welds have been designed in order to experimentally simulate a proportional multiaxial stress state in the weld root. In published literature, specimens with weld seam inclinations α with respect to the applied loading within a range of 0° to 45° are studied. In this study, the specimens were manufactured in 0°, 45°, 60° and 70° inclinations, refer to Fig.…”

“…Figure c shows that with the increase in weld seam inclination, the contribution of shear stresses increases while the contribution of normal stresses decreases. Based on the multiaxial stress ratio and gap for producing new results (especially in high multiaxial stress ratio regime) identified in, four different weld seam inclinations (0°, 45°, 60° and 70°) were selected for the designing of the specimen.…”

“…Eventually, widths of 100 mm for 0°, 70 mm for 45°, 55 mm for 60° and 40 mm for 70° specimens were chosen. The test specimens in this paper and those reported in were numerically studied using the software package Ansys version 14.5.7 (Workbench). Meshing (solid elements) and modelling of weld root notch with reference radius 1.0 mm was carried out according to guidelines from IIW.…”

“…In the case of re‐evaluated shear‐dominated joints, design methods were found to tend towards slightly non‐conservative estimates. In, the fatigue behaviour of weld defects of a certain angle to applied stress is studied by testing partially penetrated butt welded joints with weld seam inclinations of 0°, 15° and 45° to applied loading. It was observed that fatigue cracks initiated from the edge of lack of penetration (LOP) and propagated towards the thickness direction in the same plane as LOP.…”

Failure analysis on circulating water pump of duplex stainless steel in 1000MW ultra-supercritical thermal power unit

“…Wahab [22] pointed out that the weld imperfections such as LOP, porosity, lack of fusion, undercut effectively reduced the fatigue crack propagation life and fatigue strength of welded joints by studying a variety of weld imperfections. Kim [23] pointed out that the LOPs significantly reduced the fatigue lives of 9 mm thick transverse butt welded specimens without weld reinforcements, showing shorter fatigue life than JSSC-B. Sanders and Lawrence [24] studied the effects of lack of penetration (LOP) and lack of fusion (LOF) on the fatigue behavior of butt welds.…”