scholarly journals A coupled thermo-mechanical model of friction stir welding

2012 ◽  
Vol 16 (2) ◽  
pp. 527-534 ◽  
Author(s):  
Darko Veljic ◽  
Milenko Perovic ◽  
Aleksandar Sedmak ◽  
Marko Rakin ◽  
Miroslav Trifunovic ◽  
...  
Keyword(s):  
Friction Stir Welding ◽  
Plastic Strain ◽  
Mechanical Model ◽  
Temperature Fields ◽  
Maximum Temperature ◽  
Bottom Surface ◽  
Al Alloy ◽  
Fe Model ◽  
Arbitrary Lagrangian Eulerian ◽  
Friction Stir

A coupled thermo-mechanical model was developed to study the temperature fields, the plunge force and the plastic deformations of Al alloy 2024-T351 under different rotating speed: 350, 400 and 450 rpm, during the friction stir welding (FSW) process. Three-dimensional FE model has been developed in ABAQUS/Explicit using the arbitrary Lagrangian-Eulerian formulation, the Johnson-Cook material law and the Coulomb?s Law of friction. Numerical results indicate that the maximum temperature in the FSW process is lower than the melting point of the welding material. The temperature filed is approximately symmetrical along the welding line. A lower plastic strain region can be found near the welding tool in the trailing side on the bottom surface. With increasing rotation speed, the low plastic strain region is reduced. When the rotational speed is increased, the plunge force can be reduced. Regions with high equivalent plastic strains are observed which correspond to the nugget and the flow arm.

scholarly journals Analysis of the tool plunge in friction stir welding - comparison of aluminium alloys 2024 T3 and 2024 T351

2016 ◽  
Vol 20 (1) ◽  
pp. 247-254
Author(s):  
Darko Veljic ◽  
Bojan Medjo ◽  
Marko Rakin ◽  
Zoran Radosavljevic ◽  
Nikola Bajic
Keyword(s):  
Friction Stir Welding ◽  
Plastic Strain ◽  
Heat Generation ◽  
Aluminium Alloys ◽  
Three Dimensional ◽  
Equivalent Plastic Strain ◽  
Fe Model ◽  
Arbitrary Lagrangian Eulerian ◽  
Friction Stir ◽  
Tool Pin

Temperature, plastic strain and heat generation during the plunge stage of the friction stir welding (FSW) of high-strength aluminium alloys 2024 T3 and 2024 T351 are considered in this work. The plunging of the tool into the material is done at different rotating speeds. A three-dimensional finite element (FE) model for thermomechanical simulation is developed. It is based on arbitrary Lagrangian-Eulerian formulation, and Johnson-Cook material law is used for modelling of material behaviour. From comparison of the numerical results for alloys 2024 T3 and 2024 T351, it can be seen that the former has more intensive heat generation from the plastic deformation, due to its higher strength. Friction heat generation is only slightly different for the two alloys. Therefore, temperatures in the working plate are higher in the alloy 2024 T3 for the same parameters of the plunge stage. Equivalent plastic strain is higher for 2024 T351 alloy, and the highest values are determined under the tool shoulder and around the tool pin. For the alloy 2024 T3, equivalent plastic strain is the highest in the influence zone of the tool pin.

scholarly journals Experimental and numerical thermo-mechanical analysis of friction stir welding of high-strength alluminium alloy

2014 ◽  
Vol 18 (suppl.1) ◽  
pp. 29-38 ◽  
Author(s):  
Darko Veljic ◽  
Aleksandar Sedmak ◽  
Marko Rakin ◽  
Nikola Bajic ◽  
Bojan Medjo ◽  
...  
Keyword(s):  
Friction Stir Welding ◽  
Welding Process ◽  
Vertical Direction ◽  
High Strength ◽  
Temperature Fields ◽  
Bottom Surface ◽  
Arbitrary Lagrangian Eulerian ◽  
Welding Zone ◽  
Friction Stir ◽  
Tool Shoulder

This paper presents experimental and numerical analysis of the change of temperature and force in the vertical direction during the friction stir welding of high-strength aluminium alloy 2024 T3. This procedure confirmed the correctness of the numerical model, which is subsequently used for analysis of the temperature field in the welding zone, where it is different to determine the temperature experimentally. 3D finite element model is developed using the software package Abaqus; arbitrary Lagrangian-Eulerian formulation is applied. Johnson-Cook material law and Coulomb?s Law of friction are used for modelling the material behaviour. Temperature fields are symmetrical with respect to the welding line. The temperature values below the tool shoulder, i.e. in the welding zone, which are reached during the plunge stage, are approximately constant during the entire welding process and lie within the interval 430-502?C. The temperature of the material in the vicinity of the tool is about 500?C, while the values on the top surface of the welding plates (outside the welding zone, but close to the tool shoulder) are about 400?C. The temperature difference between the top and bottom surface of the plates is small, 10-15?C.

scholarly journals A Modified Analytical Heat Source Model for Numerical Simulation of Temperature Field in Friction Stir Welding

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Xiangqian Liu ◽  
Yan Yu ◽  
Shengli Yang ◽  
Huijie Liu
Keyword(s):  
Heat Flux ◽  
Friction Stir Welding ◽  
Analytical Model ◽  
Heat Generation ◽  
Tilt Angle ◽  
Temperature Fields ◽  
Analytical Models ◽  
Maximum Temperature ◽  
Thermal Cycles ◽  
Friction Stir

In the conventional analytical model used for heat generation in friction stir welding (FSW), the heat generated at the pin/workpiece interface is assumed to distribute uniformly in the pin volume, and the heat flux is applied as volume heat. Besides, the tilt angle of the tool is assumed to be zero for simplicity. These assumptions bring about simulating deviation to some extent. To better understand the physical nature of heat generation, a modified analytical model, in which the nonuniform volumetric heat flux and the tilt angle of the tool were considered, was developed. Two analytical models are then implemented in the FEM software to analyze the temperature fields in the plunge and traverse stage during FSW of AA6005A-T6 aluminum hollow extrusions. The temperature distributions including the maximum temperature and heating rate between the two models are different. The thermal cycles in different zones further revealed that the peak temperature and temperature gradient are very different in the high-temperature region. Comparison shows that the modified analytical model is accurate enough for predicting the thermal cycles and peak temperatures, and the corresponding simulating precision is higher than that of the conventional analytical model.

scholarly journals Temperature fields in linear stage of friction stir welding: Effect of different material properties

2019 ◽  
Vol 23 (6 Part B) ◽  
pp. 3985-3992
Author(s):  
Darko Veljic ◽  
Marko Rakin ◽  
Bojan Medjo ◽  
Mihailo Mrdak ◽  
Aleksandar Sedmak
Keyword(s):  
Friction Stir Welding ◽  
Numerical Models ◽  
Welding Process ◽  
High Strength ◽  
Temperature Fields ◽  
Arbitrary Lagrangian Eulerian ◽  
Friction Stir ◽  
Strain And Strain Rate ◽  
The Difference ◽  
Weld Area

Friction stir welding is one of the procedures for joining the parts in solid state. Thermo-mechanical simulation of the friction stir welding of high-strength aluminium alloys 2024 T3 and 2024 T351 is considered in this work. Numerical models corresponding to the linear welding stage are developed in Abaqus software package. The material behaviour is modelled by Johnson-Cook law (which relates the yield stress with temperature, strain and strain rate), and the Arbitrary Lagrangian-Eulerian technique is applied. The difference in thermo-mechanical behaviour between the two materials has been analysed and commented. The main quantities which are considered are the temperature in the weld area, plastic strain, as well as the rate of heat generation during the welding process.

Effects of Heat Dissipation from Friction Stir Welding to Microstructures of Semi-Solid Cast 6063 Al Alloy

2021 ◽  
Vol 904 ◽  
pp. 70-75
Author(s):  
Chaiyoot Meengam ◽  
Kittima Sillapasa ◽  
Yotsakorn Pratumwal ◽  
Somboon Otarawanna
Keyword(s):  
Friction Stir Welding ◽  
Heat Dissipation ◽  
Maximum Temperature ◽  
Al Alloy ◽  
Element Analysis ◽  
Friction Stir ◽  
Tool Shoulder ◽  
Measurement Results ◽  
6063 Al Alloy ◽  
Semi Solid

In this work, temperature distribution in semi-solid cast 6063 aluminum alloy workpieces during friction stir welding (FSW) was determined by finite element analysis (FEA). The FEA results were validated by comparing them with the measurement results from thermocouples. The maximum temperature of 534.2oC was predicted at the workpiece surface contacted with the tool shoulder. The temperature profiles obtained from FEA were used to explain microstructural changes during FSW. It was observed that relatively high temperature made α-Al grains became elongated and Mg2Si intermatalics turned into a rod-like morphology with round edges.

Thermo-Mechanical Coupled Analysis of Deformation Behavior in Friction Stir Welding Process of Aluminum 7075 Plate with Conical Pin

2011 ◽  
Vol 338 ◽  
pp. 618-621
Author(s):  
Zheng Hua Guo ◽  
Gang Yao Zhao ◽  
Li Ming Ke ◽  
Li Xing ◽  
Hai Li Li
Keyword(s):  
Friction Stir Welding ◽  
Deformation Behavior ◽  
Maximum Temperature ◽  
Coupled Analysis ◽  
Outer Side ◽  
Fe Model ◽  
Alloy Plate ◽  
Friction Stir ◽  
Tool Shoulder ◽  
Aluminum 7075

A 3D elastic-plastic and coupled thermo-mechanical FE model for friction stir welding(FSW) of aluminum 7075 plate with conical pin was developed based on the dynamic explicit code ABAQUS/explicit. Then temperature distribution and deformation behavior of 7075 aluminum alloy plate in FSW process were simulated and analyzed. The results show that the temperature is distributed in the plate with an approximate ellipse shape and decreases from the edge of the tool shoulder to the outer side of the plate. Furthermore, the maximum temperature zone decreases gradually from tool shoulder to the bottom of the plate. In the welding zone, the equivalent strain is also distributed with ring shapes, and it decreases from the edge of the tool shoulder to the outer side of the plate.

scholarly journals Heat generation during plunge stage in friction stir welding

2013 ◽  
Vol 17 (2) ◽  
pp. 489-496 ◽  
Author(s):  
Darko Veljic ◽  
Marko Rakin ◽  
Milenko Perovic ◽  
Bojan Medjo ◽  
Zoran Radakovic ◽  
...  
Keyword(s):  
Friction Stir Welding ◽  
Heat Generation ◽  
Slip Rate ◽  
Element Model ◽  
Numerical Results ◽  
Frictional Heat ◽  
Al Alloy ◽  
Arbitrary Lagrangian Eulerian ◽  
Workpiece Material ◽  
Friction Stir

This paper deals with the heat generation in the Al alloy Al2024-T3 plate under different rotating speeds and plunge speeds during the plunge stage of friction stir welding (FSW). A three-dimensional finite element model (FEM) is developed in the commercial code ABAQUS/Explicit using the arbitrary Lagrangian-Eulerian formulation, the Johnson-Cook material law and Coulomb?s Law of friction. The heat generation in FSW can be divided into two parts: frictional heat generated by the tool and heat generated by material deformation near the pin and the tool shoulder region. Numerical results obtained in this work indicate a more prominent influence from the friction-generated heat. The slip rate of the tool relative to the workpiece material is related to this portion of heat. The material velocity, on the other hand, is related to the heat generated by plastic deformation. Increasing the plunging speed of the tool decreases the friction-generated heat and increases the amount of deformation-generated heat, while increasing the tool rotating speed has the opposite influence on both heat portions. Numerical results are compared with the experimental ones, in order to validate the numerical model, and a good agreement is obtained.

Development of a Combined Method between MPS and FEM for Simulating Friction Stir Welding

2014 ◽  
Vol 783-786 ◽  
pp. 2531-2536
Author(s):  
Hisashi Serizawa ◽  
Junji Shimazaki ◽  
Fumikazu Miyasaka ◽  
Gaku Yoshikawa ◽  
Hidekazu Murakawa
Keyword(s):  
Friction Stir Welding ◽  
Plastic Strain ◽  
Maximum Temperature ◽  
The Finite Element Method ◽  
Combined Method ◽  
Friction Stir ◽  
Temperature Distributions ◽  
Inhomogeneous Temperature ◽  
Moving Particle ◽  
Good Agreement

In order to simulate the large deformation surrounding the rotational tool of friction stir welding (FSW) precisely, the moving particle semi-implicit (MPS) method was employed and the temperature distributions near the tool were obtained. Also, the temperature distributions in the whole model except for the area computed by MPS were calculated by the finite element method (FEM) and then the elastic-plastic analysis was conducted using the temperature distributions obtained by MPS and FEM. The inhomogeneous temperature distributions through the thickness near the joint line could be simulated and the maximum temperature distributions computed had a good agreement with the experiments. In addition, the longitudinal plastic strain distributions indicates that this plastic strain near the tool is not governed by only the temperature distributions and the influence of plastic flow should be taken into account.

scholarly journals Bobbin Tool Friction Stir Welding of Aluminum Thick Lap Joints: Effect of Process Parameters on Temperature Distribution and Joints’ Properties

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4585
Author(s):  
Mohamed M. Z. Ahmed ◽  
Mohamed I. A. Habba ◽  
Mohamed M. El-Sayed Seleman ◽  
Khalil Hajlaoui ◽  
Sabbah Ataya ◽  
...  
Keyword(s):  
Friction Stir Welding ◽  
Welding Speed ◽  
Travel Speed ◽  
Lap Joints ◽  
Stir Zone ◽  
Maximum Temperature ◽  
Al Alloy ◽  
Friction Stir ◽  
Pin Geometry ◽  
Zone Temperature

Bobbin tool friction stir welding (BT-FSW) is characterized by a fully penetrated pin and double-sided shoulder that promote symmetrical solid-state joints. However, control of the processing parameters to obtain defect-free thick lap joints is still difficult and needs more effort. In this study, the BT-FSW process was used to produce 10 mm AA1050-H14 similar lap joints. A newly designed bobbin tool (BT) with three different pin geometries (cylindrical, square, and triangular) and concave shoulders profile was designed, manufactured, and applied to produce the Al alloy lap joints. The experiments were carried out at a constant tool rotation speed of 600 rpm and a wide range of various welding travel speeds of 200, 400, 600, 800, and 1000 mm/min. The generated temperature during the BT-FSW process was recorded and analyzed at the joints’ center line, and at both advancing and retreating sides. Visual inspection, macrostructures, hardness, and tensile properties were investigated. The fracture surfaces after tensile testing were also examined. The results showed that the pin geometry and travel speed are considered the most important controlling parameters in BT-FSW thick lap joints. The square (Sq) pin geometry gives the highest BT-FSW stir zone temperature compared to the other two pins, cylindrical (Cy) and triangular (Tr), whereas the Tr pin gives the lowest stir zone temperature at all applied travel speeds from 200 to 1000 mm/min. Furthermore, the temperature along the lap joints decreased with increasing the welding speed, and the maximum temperature of 380 °C was obtained at the lowest travel speed of 200 mm/min with applying Sq pin geometry. The temperature at the advancing side (AS) was higher than that at the retreating side (RS) by around 20 °C. Defect-free welds were produced using a bobbin tool with Cy and Sq pin geometries at all the travel welding speeds investigated. BT-FSW at a travel speed of 200 mm/min leads to the highest tensile shear properties, in the case of using the Sq pin. The hardness profiles showed a significant effect for both the tool pin geometry and the welding speed, whereas the width of the softened region is reduced dramatically with increasing the welding speed and using the triangular pin.

A 3D Coupled Thermo-Mechanical FE Model for Friction Stir Welding of 7075 Aluminum Alloy Plate

2011 ◽  
Vol 314-316 ◽  
pp. 346-350 ◽  
Author(s):  
Zheng Hua Guo ◽  
Gang Yao Zhao ◽  
Li Ming Ke ◽  
Li Xing ◽  
Shun Feng Zhu
Keyword(s):  
Plastic Deformation ◽  
Aluminum Alloy ◽  
Friction Stir Welding ◽  
Bottom Surface ◽  
Fe Model ◽  
7075 Aluminum Alloy ◽  
Alloy Plate ◽  
Friction Stir ◽  
Plastic Deformation Behavior ◽  
Aluminum Alloy Plate

Friction stir welding(FSW), a new solid-state joining process, is wildly used in the fields of aviation, aerospace and other high technology industries for many advantages over traditional fusion welding. Computer modeling is an important tool for the prediction and optimization of the FSW process. According to the characteristics of FSW of 7075 aluminum alloy plate, a 3D coupled thermo-mechanical FE model of this process was built under the ABAQUS/explicit environment based on the solution of several key techniques, such as heat boundary condition treating, material properties definition, ALE adaptive meshing technology, etc., and validated experimentally. Then, simulation and analysis of the complex plastic deformation behavior of the process were carried out. The results show that in the stable stage of the welding, the zone of equivalent plastic deformation decreases from the top surface of weld to the bottom surface; the plastic deformation of metal ahead of the welding tool is larger than that behind the welding tool; moreover the zone of equivalent plastic deformation is concentrated behind the tool.

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