What is Friction Stir Welding (FSW)? | Abaqus FSW
Friction Stir Welding (FSW) is a solid-state welding process used to join two pieces of metal together. It was developed in the 1990s by The Welding Institute (TWI) and is considered a significant advancement in modern welding technology. In friction stir welding, a cylindrical tool with a specially designed shoulder and pin is rotated and plunged into the joint between the two metal pieces. The rotation and downward pressure generate heat through friction, softening the material without reaching its melting point. As the tool moves along the joint, it stirs the softened material, forming a solid-state bond. This welding technique is particularly suitable for joining materials that are difficult to weld using traditional fusion welding methods, such as aluminum, copper, and certain high-strength alloys. It produces welds with remarkable mechanical properties, including high strength, excellent fatigue resistance, and reduced distortion compared to conventional welding techniques.
Friction stir welding offers several advantages over traditional welding methods. It eliminates the need for filler materials, reduces the risk of defects like porosity or solidification cracks, and produces welds with excellent consistency and repeatability. It also offers improved joint efficiency and can be used to weld materials with different thicknesses or dissimilar metals.
FSW has found applications in various industries, including automotive, aerospace, shipbuilding, and rail transportation. It is commonly used for fabricating structures, panels, and components that require high integrity, lightweight design, and enhanced mechanical properties.
Workshop 1: Steel-Aluminum Plate Friction Stir Welding Simulation
This tutorial includes a comprehensive video that demonstrates the Friction Stir Welding process in a detailed manner, accompanied by CAE data. In the analysis, Eulerian elements were utilized for Steel and Aluminum plates, while a Lagrangian element was employed for the tool. Throughout the analysis, the temperature distribution in both workpieces can be observed. The images provided in the document depict various stages of this process. It is evident that the temperature undergoes changes as the tool moves and rotates, with the Aluminum plate exhibiting higher temperatures compared to the Steel plate due to variations in their thermal properties.
Workshop 2: Aluminum Plates Friction Stir Welding Simulation using Eulerian approach in Abaqus
The FSW (Friction Stir Welding) problem encompasses challenges related to significant material deformation and heat transfer. In this study, a coupled Eulerian Lagrangian (CEL) model was developed using the Abaqus environment to simulate the two phases of the FSW process: plunging and welding. This file contains a step-by-step CAE and English video demonstrating the FSW of two Aluminum plates. During the analysis, the tool moves and rotates within the plates, generating heat. Friction stir welding is a solid-state welding technique that is highly regarded for its ability to join metals and alloys with diverse physical, chemical, and mechanical properties. The FSW process is intricate, involving the interaction of thermal and mechanical phenomena, such as extensive material deformation around the pin tool and substantial heat flow. By utilizing finite element modeling (FEM) of the FSW process, a deeper understanding of the impact of process parameters on the welding process and the properties of the weld seam can be achieved. Presently, FSW finite element models can be categorized into three types: thermal models, thermo-mechanical non-flow-based models, and thermo-mechanical flow-based models.
Workshop 3: Friction stir welding simulation of two Steel plates in Abaqus
The FSW (Friction Stir Welding) problem is a complex phenomenon involving material deformation and heat flow. In this study, a coupled Eulerian Lagrangian (CEL) model was developed using the Abaqus environment to simulate the welding phase of the FSW process. By employing finite element modeling (FEM) of the FSW process, a deeper understanding of how process parameters affect the welding process and the properties of the weld seam can be obtained. Currently, FSW finite element models can be categorized into three types: thermal models, thermo-mechanical non-flow-based models, and thermo-mechanical flow-based models. In flow-based models, traditional Lagrangian elements may experience significant distortion, potentially leading to a loss of accuracy in the results. To mitigate this issue, several modeling techniques are often utilized, such as adaptive re-meshing and Arbitrary Lagrangian Eulerian (ALE) methods. Flow-based models are developed using computational fluid dynamics (CFD). However, one limitation of CFD simulations is their inability to incorporate material hardening, as they typically assume rigid-viscoplastic material behavior. This file contains a CAE and English video showcasing the step-by-step FSW process of two Steel plates. During the analysis, the tool moves and rotates within the plates, generating heat.
Workshop 4: Friction stir welding simulation using SPH method
Friction stir welding (FSW) is rapidly gaining popularity as the preferred method for joining aluminum alloys. This solid-state process allows for the creation of high-quality welds with impressive efficiency. Unlike conventional fusion welding techniques that involve melting and solidification, FSW avoids many types of defects due to its solid-state nature. However, depending on the chosen process parameters, FSW joints can still exhibit volumetric defects that can compromise the overall strength of the joint. This video focuses on simulating Friction Stir Welding using the Smoothed Particle Hydrodynamics (SPH) method in Abaqus, specifically in the context of thermal analysis. Since Abaqus does not directly support the coupling of SPH elements with temperature degrees, modifications were made to apply temperature to these elements. The analysis consists of three steps, each involving changes in stress and temperature.
You can watch demo here.
Workshop 5: Friction Stir Spot Welding Thermal- mechanical simulation using ALE method
The automotive industry is increasingly turning to aluminum for its lightweight properties and fuel efficiency benefits. However, this presents a challenge in finding efficient and cost-effective methods to join aluminum parts while also characterizing the mechanical properties of the welds. Various techniques are available for aluminum joining, including Tungsten Inert Gas (TIG), Metal Arc Welding (MIG), Resistance Spot Welding (RSW), as well as non-melting methods like Self-Piercing Riveting (SPR), clinching, and bonding with structural adhesives. Spot Friction Stir Welding (SFW), also known as Friction Stir Spot Welding (FSSW), is a solid-state joining technique developed by Mazda Corporation and Kawasaki Heavy Industries in 2003 as a variant of the “linear” Friction Stir Welding (FSW) process specifically for aluminum alloys.
FSW and SFW have shown promise in practical applications for welding aluminum alloys in the automotive industry. These methods have successfully produced high-quality joints and offer advantages in terms of tensile strength, process time, and cost compared to other methods. In a study comparing lap-shear strength, it was found that joints produced by the SFW process were comparable to those produced by RSW or SPR. However, the process time required for joining sheets using SFW increased with increasing thickness. SFW offers advantages such as lower power consumption and running costs compared to RSW, as well as a cleaner work environment without weld spatter. Additionally, the SFW process boasts long tool life, high productivity, and high reliability.
In this simulation, the Friction Stir Spot Welding process is investigated using the Arbitrary Lagrangian-Eulerian method. The base material is aluminum alloy, while the tool is modeled as a rigid body. A dynamic explicit step with modifications to consider the temperature variable is employed.
The main focus of this simulation is to utilize an appropriate Arbitrary Lagrangian-Eulerian (ALE) method to attain optimal results within a consistent timeframe. In the analysis, a rotating tool with axial velocity is inserted into the aluminum plate, resulting in observable stress distribution and temperature patterns.
Workshop 6: Acrylonitrile butadiene styrene polymer friction stir welding simulation
This tutorial focuses on investigating the simulation of friction stir welding (FSW) of acrylonitrile butadiene styrene (ABS) polymer using Abaqus. Polymer materials have experienced significant growth and are now widely used in various manufacturing industries due to their excellent strength-to-weight ratio, enhanced toughness, and cost-effectiveness. Polymer joints are commonly employed in automotive applications, such as joining clear or tinted PC parts to opaque ABS bodies, as seen in automotive tail-lights and indicators.
Polymers possess distinct rheological properties, particularly in terms of melt viscosity, resulting in different flow behaviors compared to metals. This variation in flow behavior is a significant factor contributing to the diverse range of process parameters in FSW for polymer materials. Polymers with higher melt temperature and viscosity require higher tool rotational speeds and lower tool traverse speeds to generate sufficient heat and achieve high joint efficiency. Joining dissimilar polymers presents a challenge due to differences in their mechanical, chemical, thermal, metallurgical, and physical properties. However, when similar materials are used, the material compatibility is improved, leading to more efficient joining.
In the simulation, the ABS part is modeled as a three-dimensional Eulerian part, while the tool is represented as a three-dimensional solid part.
To simulate the behavior of the tool, a steel material with elastic-plastic data and thermal parameters is utilized. For modeling the ABS material, elastic data and the Johnson-Cook plasticity model with thermal conductivity, specific heat, and other relevant properties are employed. The dynamic temperature explicit step is considered suitable for this type of analysis, allowing for accurate representation of temperature changes. The friction coefficient, along with the heat generation parameter, is used to define the contact properties between surfaces. To reduce computational volume during the FSW process, a rigid body constraint is applied to the tool. The Eulerian part’s sides are assigned a fixed boundary condition, while the tool is given axial and rotational velocities. Uniform material assignment is used to model the location of the Eulerian material. It is important to have a fine mesh in order to obtain accurate and reliable results. Once the simulation is complete, various results such as temperature distribution, nodal temperature, stress, strain, and other relevant data can be obtained.
It would be helpful to see Abaqus Documentation to understand how it would be hard to start an Abaqus simulation without any Abaqus tutorial.
Francesca –
Does this tutorial package include comprehensive materials and guidance that will allow me to become familiar with friction stir welding simulation in the Abaqus software and use it in real projects? Will this package help me obtain more accurate results regarding residual stresses, deviations, and weld quality in the friction stir welding process?
Experts Of CAE Assistant Group –
Exactly, it does. It has some courses with step by step guideline to simulate in Abaqus