Friction stir welding induced residual stresses in thick steel plates from experimental and numerical analysis

Friction Stir Welding (FSW) is an innovative solid-state joining process, which is gaining a great deal of attention in several applicative sectors. The opportune definition of process parameters, i.e. minimizing residual stresses, is crucial to improve joint reliability in terms of static and dynamic performance. Longitudinal residual stresses, induced by FSW in AA2024-T3 butt joints, have been inferred by means of a recently developed technique, namely the contour method. Two approaches to stress measurement have been adopted; the former is based on the assumption of uniform material properties, the latter takes into account microstructural effects and material properties variations in the welding zones. The influence of process parameters, namely rotating and welding speeds, on stress distribution is also discussed.

Download Full-text

Residual stresses in AA7108 aluminium alloy sheets joined by friction stir welding

Nondestructive Testing And Evaluation ◽

10.1080/10589750802495513 ◽

2009 ◽

Vol 24 (3) ◽

pp. 301-309 ◽

Cited By ~ 11

Author(s):

Saliha Gachi ◽

Farid Belahcene ◽

Fouad Boubenider

Keyword(s):

Friction Stir Welding ◽

Residual Stresses ◽

Aluminium Alloy ◽

Friction Stir

Download Full-text

Process - Property Correlation of Friction Stir Welding of Marine Grade Aluminium Alloy 5083 Using Finite Element Analysis

The International Journal of Maritime Engineering ◽

10.5750/ijme.v163ia2.757 ◽

2021 ◽

Vol 163 (A2) ◽

Author(s):

M Sahu ◽

A Paul ◽

S Ganguly

Keyword(s):

Mechanical Properties ◽

Residual Stress ◽

Finite Element ◽

Friction Stir Welding ◽

Residual Stresses ◽

Process Variables ◽

Friction Stir ◽

Stress Region ◽

Longitudinal Residual Stress ◽

Process Property

In this article, a 3D finite element based thermo-mechanical model for friction stir welding (FSW) of a marine-grade aluminium alloy 5083 is proposed. The model demonstrates the thermal evaluation and the distribution of residual stresses and strains under the variation of process variables. The temperature profile of the weld joint during the FSW process and the mechanical properties of the joints are also experimentally evaluated. The necessary calibration of the model for the correct implementation of the thermal loading, mechanical loading, and boundary conditions was performed using the experimental results. The model simulation and experimental results are analyses in view of the process-property correlation study. The residual stress was evaluated along, and across the weld, centreline referred as longitudinal and transverse residual stresses, respectively. The magnitude of longitudinal residual stress is noted 60-80% higher than that of the transverse direction. The longitudinal residual stress generated a tensile oval shaped stress region around the tool shoulder confined to a maximum distance of about 25mm from the axis of the tool along the weld line. It encompasses the weld-nugget to thermo-mechanically affected zone (TMAZ), while the parent metal region is mostly experiences the compressive residual stresses. However, the transverse residual stress region appears like wing shaped region spread out in both the advancing and retreating side of the weld and occupying approximately double the area as compared to the longitudinal residual stresses. Overall, the study revealed a corelation between the FSW process variables such as welding speed and the tool rotational speed with the residual stress and the mechanical properties of the joint.

Download Full-text