Predicting residual thermal stresses in friction stir welded metals

Khandkar, Mir Zahedul H.; Khan, Jamil A.; Reynolds, Anthony P.; Sutton, Michael A.

doi:10.1016/j.jmatprotec.2005.12.013

Cited by 127 publications

(60 citation statements)

References 7 publications

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“…Moreover, different thermal models were used in a coupled condition to investigate the mechanical behavior and the residual stress [94]. In a three dimensional thermomechanical FE model, Dong et al [95] used an axisymmetric Lagrangian method for investigating forces impact on the tool in different welding transverse and rotational speeds.…”

Section: Lagrangian Eulerian Methodsmentioning

confidence: 99%

A Comparison of Different Finite Element Methods in the Thermal Analysis of Friction Stir Welding (FSW)

Meyghani

Awang

Emamian

et al. 2017

Metals

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Friction Stir Welding (FSW) is a novel kind of welding for joining metals that are impossible or difficult to weld by conventional methods. Three-dimensional nature of FSW makes the experimental investigation more complex. Moreover, experimental observations are often costly and time consuming, and usually there is an inaccuracy in measuring the data during experimental tests. Thus, Finite Element Methods (FEMs) has been employed to overcome the complexity, to increase the accuracy and also to reduce costs. It should be noted that, due to the presence of large deformations of the material during FSW, strong distortions of mesh might be happened in the numerical simulation. Therefore, one of the most significant considerations during the process simulation is the selection of the best numerical approach. It must be mentioned that; the numerical approach selection determines the relationship between the finite grid (mesh) and deforming continuum of computing zones. Also, numerical approach determines the ability of the model to overcome large distortions of mesh and provides an accurate resolution of boundaries and interfaces. There are different descriptions for the algorithms of continuum mechanics include Lagrangian and Eulerian. Moreover, by combining the above-mentioned methods, an Arbitrary Lagrangian-Eulerian (ALE) approach is proposed. In this paper, a comparison between different numerical approaches for thermal analysis of FSW at both local and global scales is reviewed and the applications of each method in the FSW process is discussed in detail. Observations showed that, Lagrangian method is usually used for modelling thermal behavior in the whole structure area, while Eulerian approach is seldom employed for modelling of the thermal behavior, and it is usually employed for modelling the material flow. Additionally, for modelling of the heat affected zone, ALE approach is found to be as an appropriate approach. Finally, several significant challenges and subjects remain to be addressed about FSW thermal analysis and opportunities for the future work are proposed.

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Section: Lagrangian Eulerian Methodsmentioning

confidence: 99%

A Comparison of Different Finite Element Methods in the Thermal Analysis of Friction Stir Welding (FSW)

Meyghani

Awang

Emamian

et al. 2017

Metals

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“…Moreover, these numerical models have also the aim to develop the process through the research of optimal parameters minimising the amount of trial and error. Khandkar et al [17] have made an uncoupled thermomechanical model for some aluminium alloys and 304 L stainless steel based on torque input for calculating temperature and then residual stress. Chen et al [18] have developed a 3D numerical model to study the thermal impact and evolution of the residual stresses in the welded joints.…”

Section: Residual Stresses In Fsw and Lafsw Processesmentioning

confidence: 99%

Residual Stress in Friction Stir Welding and Laser-Assisted Friction Stir Welding by Numerical Simulation and Experiments

Casavola¹,

Cazzato²,

Moramarco³

2018

Residual Stress Analysis on Welded Joints by Means of Numerical Simulation and Experiments

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The friction stir welding (FSW) has become an important welding technique to join materials that are difficult to weld by traditional fusion welding technology. In this technique, the material is not led to fusion, and the joint is the result of the rotation and movement along the welding line of the tool that causes softening of material due to frictional heat and the stirring of the same. In FSW, the temperature does not reach the fusion value of the materials, and this helps to decrease the residual stress values. However, due to the higher force involved in the weld and, thus, the rigid clamping used, the residual stresses are not low in general in this technique. As the presence of high residual stress values influences the post-weld mechanical properties, e.g. fatigue properties, it is important to investigate the residual stress distribution in the FSW welds. In this chapter, two numerical models that predict temperatures and residual stresses in friction stir welding and laser-assisted friction stir welding will be described. Experimental measurements of temperatures and residual stress will be carried out to validate the prediction of the models.

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“…The calibrated values are in the expected range. Typical values of heat transfer coefficients reported in the literature range from h cond = 350 W/m 2 ·K in Chao et al [19] to h cond = 5000 W/m 2 ·K in Khandkar et al [20].…”

Section: Validation Of Numerical Model From Experimental Datamentioning

confidence: 99%

Experimental Validation of an FSW Model with an Enhanced Friction Law: Application to a Threaded Cylindrical Pin Tool

Dialami

Cervera

Chiumenti

et al. 2017

Metals

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This work adopts a fast and accurate two-stage computational strategy for the analysis of FSW (Friction stir welding) processes using threaded cylindrical pin tools. The coupled thermo-mechanical problem is equipped with an enhanced friction model to include the effect of non-uniform pressure distribution under the pin shoulder. The overall numerical strategy is successfully validated by the experimental measurements provided by the industrial partner (Sapa). The verification of the numerical model using the experimental evidence is not only accomplished in terms of temperature evolution but also in terms of torque, longitudinal, transversal and vertical forces.

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Predicting residual thermal stresses in friction stir welded metals

Cited by 127 publications

References 7 publications

A Comparison of Different Finite Element Methods in the Thermal Analysis of Friction Stir Welding (FSW)

A Comparison of Different Finite Element Methods in the Thermal Analysis of Friction Stir Welding (FSW)

Residual Stress in Friction Stir Welding and Laser-Assisted Friction Stir Welding by Numerical Simulation and Experiments

Experimental Validation of an FSW Model with an Enhanced Friction Law: Application to a Threaded Cylindrical Pin Tool

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