Thermo-mechanical modelling of the Friction Stir Spot Welding process: Effect of the friction models on the heat generation mechanisms

Abstract

Friction Stir Spot Welding involves complex physical phenomena, which are very difficult to probe experimentally. In this regard, the numerical simulation may play a key role to gain insight into this complex thermo-mechanical process. It is often used to mimic specific experimental conditions to forecast outputs that may be substantial to analyse and elucidate the mechanisms behind the Friction Stir Spot Welding process. This welding technique uses frictional heat generated by a rotating tool to join materials. The heat generation mechanisms are governed by a combination of sliding and sticking contact conditions. In the numerical simulation, these contact conditions are thoroughly dependent on the used friction model. Hence, a successful prediction of the process relies on the appropriate selection of the contact model and parameters. This work aims to identify the pros and cons of different friction models in modelling combined sliding-sticking conditions. A three-dimensional coupled thermo-mechanical FE model, based on a Coupled Eulerian-Lagrangian formulation, was developed. Different friction models are adopted to simulate the Friction Stir Spot Welding of the AA6082-T6 aluminium alloy. For these friction models, the temperature evolution, the heat generation, and the plastic deformation were analysed and compared with experimental results. It was realized that numerical analysis of Friction Stir Spot Welding can be effective and reliable as long as the interfacial friction characteristics are properly modelled. This approach may be used to guide the contact modelling strategy for the simulation of the Friction Stir Spot Welding process and its derivatives.

A Review on Friction Stir Welding/Processing: Numerical Modeling

“…Their findings revealed that the CEL modeling technique was not only more accurate, but also simpler to use and more computationally efficient in comparison to the ALE modeling technique. Hannachi and colleagues [129] examined and compared various friction models for their applicability in modeling the FSSW process of AA6082-T6 aluminum utilizing a CEL formulation. The models they investigated included the conventional Coulomb model, the modified Coulomb model, and the temperature-dependent friction coefficient-based model.…”

Numerical and Experimental Analyses of Developed Friction Stir Spot Welding (DFSSW) Based on Systematic Design Process Approach

“…An advanced three-dimensional numerical simulation was developed by Hannachi et al [ 12 ] to analyze the thermomechanical phenomena that occurred through the Friction Stir Spot Welding (FSSW) process. AA6082-T6 aluminum sheets were selected.…”

Investigation of the effect of welding and rotational speed on strain and temperature during friction stir welding of AA5083 and AA7075 using the CEL approach

“…They discovered that the sample RS had higher temperatures and residual stresses than the sample AS, and they also discovered a strong correlation between simulation and experiment data. Hannachi et al [34] investigated different friction models in friction stir welding modeling and examined the advantages and disadvantages of each model. For this purpose, they developed a model using a CEL formulation.…”