Simulation of a New Solid State Joining Process Using Single-Shoulder Two-Pin Tool

2008 ◽  
Vol 130 (4) ◽  
Author(s):  
S. Mukherjee ◽  
A. K. Ghosh
Keyword(s):  
New Technology ◽  
Local Heating ◽  
Reaction Force ◽  
Three Dimensional ◽  
Welding Process ◽  
Tool Material ◽  
Element Model ◽  
Tool Design ◽  
Friction Stir ◽  
Three Dimensional Finite Element

In friction stir welding (FSW) process, heat is generated by friction between the tool and the workpiece. The conventional tool design employs a cylindrical shoulder with a single profiled pin. A new process has been designed that uses two-pin tool under the same shoulder to increase shear deformation within workpiece that can enhance local heating where joining occurs. The design employs two closely spaced pins rotating in the same direction within the workpiece under a separately controlled shoulder. The process is distinctly different from the Twin-stir™ variant of FSW in which each pin performs an independent function and non-interacting. Prior to gathering considerable experimental data with new equipment, a fully coupled themomechanical three-dimensional finite element model has been developed to compare the existing single-pin technology with new technology of friction driven stitch welding process. The computational results for the two-pin tool show considerable shearing along the joining interface, enhanced local heating, and a reduced reaction force on the pins, which are described in this paper. The results of this study indicate that the two-pin tool design with a separate shoulder, with the same direction of pin rotation, can be a superior design in comparison to the conventional single-pin FSW tool and could minimize damage to tool material.

Three-Dimensional Finite Element Modeling of Hard Turning Processes

Manufacturing ◽  
2003 ◽  
Author(s):  
T. D. Marusich ◽  
R. J. McDaniel ◽  
S. Usui ◽  
J. A. Fleischmann ◽  
T. R. Kurfess ◽  
...  
Keyword(s):  
Finite Element ◽  
Hard Turning ◽  
Metal Cutting ◽  
Three Dimensional ◽  
Constitutive Models ◽  
Tool Material ◽  
Dimensional Accuracy ◽  
Element Model ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

Hard turning processes promise affordable fabrication of machined components with high dimensional accuracy requirements. In an effort to achieve the desired economics a vast array of process variables must be considered including tool material, geometry, edge preparation, wear, speed and feed selection, while maintaining part quality. One method to reduce the number of necessary experiments is through accurate and reliable modeling. A three-dimensional finite element model is presented which includes fully adaptive unstructured mesh generation, tight thermo-mechanically coupling, deformable tool-chip-workpiece contact, interfacial heat transfer across the tool-chip boundary, momentum effects at high speeds and constitutive models appropriate for high strain rate, finite deformation analyses. The model is applied to nose turning of hardened steel workpieces, HRc 60. Metal cutting tests are performed, cutting forces collected, and validation comparison is made.

scholarly journals Technology and equipment for friction stir preweld edge preparation

2021 ◽  
Vol 21 (2) ◽  
pp. 163-170
Author(s):  
Y. G. Lyudmirsky ◽  
А. N. Soloviev ◽  
М. V. Soltovets ◽  
R. R. Kotlyshev ◽  
I. V. Mironov ◽  
...  
Keyword(s):  
Finite Element ◽  
Theoretical Model ◽  
Friction Stir Welding ◽  
Geometric Model ◽  
Three Dimensional ◽  
Welding Process ◽  
Element Model ◽  
Element Mesh ◽  
Laboratory Equipment ◽  
Friction Stir

Introduction. Friction stir welding is widely used due to certain advantages of this method. Factors that reduce the strength of joints made of high-strength aluminum alloys are considered. When welding flat sheets, an effective way to increase the strength of the weld is edge thickening. The paper proposes a method for such thickening. A device is developed, calculations and experiments are carried out. Materials and Methods. Laboratory equipment has been developed to provide simultaneous thickening of two edges to be welded. The main component of this equipment is a steel roller, which is rolled along the edges of two blanks and thickens them due to plastic deformation. The same setup can be used for the friction stir welding process. To calculate the geometry of the thickened edges and the parameters of the deforming roller depending on the value of the edge settlement, a mathematical model based on the contact problem for elastic (roller) and elastoplastic (blank) bodies with a bilinear hardening law has been developed. A three-dimensional simplified geometric model of the facility with account of its symmetry has been constructed. On the contact surfaces, special contact finite elements were selected and the finite element mesh was refined. The numerical implementation of the model was carried out in the ANSYS package. Results. The theoretical model provides assessing the stress-strain state of interacting elements. On the basis of the developed finite element model, the parameters of the thickened edges are calculated, and the geometry of the thickened edges is defined. Using the developed laboratory equipment, full-scale experiments on thickening the edges of the blanks were carried out. The experimental results confirm the adequacy of the developed theoretical model and calculations based on it. The possibility of adjusting the size of the thickened edges is shown.Discussion and Conclusion. A technology for obtaining thickened edges in places of welds is proposed. It will reduce the metal consumption of structures and ensure the bearing capacity of welded joints not lower than similar characteristics of the base metal. A theoretical model of the process is developed, and a numerical experiment providing the selection of the process parameters is carried out. 

The influence of tool geometry on the thermo-mechanical and microstructural behaviour in friction stir welding of AA5086

2010 ◽  
Vol 225 (1) ◽  
pp. 1-16 ◽  
Author(s):  
H Jamshidi Aval ◽  
S Serajzadeh ◽  
A H Kokabi
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Friction Stir Welding ◽  
Three Dimensional ◽  
Element Model ◽  
Tool Geometry ◽  
Deformation Pattern ◽  
Friction Stir ◽  
Conical Tool ◽  
Three Dimensional Finite Element

In this work, the effect of tool geometric parameters on thermo-mechanical behaviour in friction stir welding of AA5086 has been investigated. For doing so, the thermo-mechanical responses of material during welding with different tools have been predicted by a three-dimensional finite-element model using the finite-element code ABAQUS. In addition, welding experiments have been carried out to study the developed microstructures and the mechanical properties of welded alloy. The results show that tool geometry significantly affects the energy input, deformation pattern, plunge force, microstructures, and mechanical properties of the joint. The conical tool with the shoulder angle of 2° has been found to produce a larger deformation region as well as higher mechanical properties comparing with the cylindrical tools employed in this research. Additionally, tensile residual stresses are developed within the region around the weld centre-line, which gradually changes to compressive ones beyond the heat-affected zone. It is found that the ratio of heat generation from plastic to friction dissipation in the conical threaded pin is 44 per cent more than the cylindrical pin with similar shoulder diameter.

Impact of Welding Sequence on the CRDM Nozzle-to-Vessel Weld Stress Analysis

2004 ◽  
Author(s):  
Yaoshan Chen ◽  
David Rudland ◽  
Gery Wilkowski
Keyword(s):  
Computing Time ◽  
Three Dimensional ◽  
Welding Process ◽  
Element Model ◽  
Three Dimensional Model ◽  
Control Rod ◽  
Moving Source ◽  
Welding Sequence ◽  
Significant Difference ◽  
Three Dimensional Finite Element

A three-dimensional finite element model is presented to simulate the welding process of the side-hill control-rod-drive-mechanism (CRDM) nozzle to the vessel head. Emphasis is given to how the weld is laid out in the analysis so that accurate residual stress results can be obtained while the required computing time is viable. In the order of complexity, three approaches are examined in this study: a) the simultaneous approach, i.e., the weld bead (therefore the heat associated with it) is put in the model in a uniform fashion; b) the piece-by-piece approach, i.e., the weld is laid out segment by segment; c) the moving-source approach where the analysis is done by simulating the moving heat source. It is found that there is a significant difference between the stress results by the uniform approach and the piece-by-piece approach. While the moving source method gives the closet representation of the welding process, the computing time for such a multi-pass, three-dimensional model is still prohibitive. The natural choice is therefore the piece-by-piece approach, with the number of segments for the weld dependent on the weld parameters and the geometries of the nozzle and vessel head.

Numerical investigation on the effect of welding speed and heat input on the residual stress of multi-pass TIG welded stainless steel pipe

2020 ◽  
pp. 095440542098133
Author(s):  
Parviz Asadi ◽  
Samaneh Alimohammadi ◽  
Omid Kohantorabi ◽  
Ali Soleymani ◽  
Ali Fazli
Keyword(s):  
Residual Stress ◽  
Stainless Steel ◽  
Numerical Investigation ◽  
Welding Speed ◽  
Heat Input ◽  
Three Dimensional ◽  
Welding Process ◽  
Element Model ◽  
Stress States ◽  
Three Dimensional Finite Element

A numerical investigation is provided to study the residual stress states in multi-pass TIG welding of stainless steel SUS304 pipe. An uncoupled thermomechanical three-dimensional finite element model is developed using the ABAQUS software for a circular weld design around the pipe. The effects of weld pass numbers, electrode moving speed, and heat input on the internal and external surface tensions of the pipe are investigated. The simulation results show that by increasing the welding speed, the axial tensile stresses decrease on the pipe surfaces. In the case of hoop stress, as the welding speed raises, the tensile and compressive stresses are increased for both two- and three-pass welding. However, the width of the stress zone becomes narrower in higher welding speeds. The hoop stresses, in comparison with the axial stresses, are more strongly influenced by the welding speed and the heat input. Furthermore, using the three-pass welding process results in much lower stresses in comparison with the two-pass one.

scholarly journals FATIGUE LIFE ESTIMATION OF A BUTT WELDED JOINT BY S-N APPROACH

2012 ◽  
pp. 95-99
Author(s):  
VINOD M. BANSODE ◽  
N.D. MISAL
Keyword(s):  
Fatigue Life ◽  
Fatigue Testing ◽  
Three Dimensional ◽  
Welding Process ◽  
Life Time ◽  
Element Model ◽  
Simulation Software ◽  
Surface Machining ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

A failure analysis based on stress life approach may be useful for predicting the life time of weld in the structure. This study presents an upcoming methodology in new three dimensional Finite Element Model to calculate the fatigue life of weld. Ansys 12.1 simulation software uses stress-life method, based on a static non-linear Structural analysis. The weld material S-N curve were experimentally determined by the Fatigue testing of the dumbell specimen as per 7608 standard. This study assumes that a flaw exist in weld due to welding process, material in-homogeneity, air voids, slugs or impurities in weld, improper surface machining and many more. This material curve is used in simulation to get more accurate results. Thus the fatigue life prediction with the material curves from experimentation will give us more accurate and close to actual failure results.

Numerical Simulation and Experiment Analysis of MIG Welding for Aluminum Alloy Extrusion

2012 ◽  
Vol 430-432 ◽  
pp. 1311-1314
Author(s):  
Zheng Zhi Luo ◽  
Yi Su Pan
Keyword(s):  
Numerical Simulation ◽  
Aluminum Alloy ◽  
Three Dimensional ◽  
Welding Process ◽  
Element Model ◽  
Mig Welding ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element ◽  
Welding Processes ◽  
Aluminum Alloy Extrusion

Welding characteristics of MIG welding for aluminum alloy extrusions are studied. In this article, the aluminum alloy is EN AW-6005A. The welding heat source and the welding processing of aluminum alloy extrusions are discussed. A three dimensional finite element model has been developed to dynamically simulate the welding process. The investigations focus on the comparison the welding heat resource of simulation and section of the experiments parts. And the residual stress of numerical simulation and tests are compared. It’s help to optimize the MIG welding processes and improve the welding quality for aluminum alloy extrusion.

A Fracture Mechanics Evaluation of an Indication in an RPV Vertical Shell Weld Produced by the Upjohn Welding Technique

2004 ◽  
Author(s):  
Hardayal S. Mehta ◽  
Wade F. Miller ◽  
M. A. Brooks
Keyword(s):  
Three Dimensional ◽  
Infinite Plate ◽  
Welding Process ◽  
Element Model ◽  
K Value ◽  
Heavy Plate ◽  
Asme Code ◽  
Three Dimensional Finite Element ◽  
Renewal Period ◽  
Welding Technique

A reactor pressure vessel (RPV) manufacturer used the Upjohn welding technique to fabricate the longitudinal and meridional seam welds in a number of RPVs. The Upjohn welding process allowed fabrication of heavy plate sections without the use of positioning devices. With this welding technique, the major dimension of fabrication flaws extends through the weld thickness rather than parallel to the thickness as with other fabrication welding techniques. One vertical weld seam of a RPV fabricated using the Upjohn weld process was examined by ultrasonic techniques consistent with PDI requirements. Flaws were detected during the ASME Code required in-service inspection. After the application of the flaw proximity rules, one indication was characterized as a planar flaw 4.24 inches long (along the weld thickness direction) and 2-inches wide. One end of the indication was located 0.7 inch from the ID surface, which included a clad thickness of 5/16 inch. The use of Section XI flaw characterization and proximity rules would have required the characterization of this flaw as a large surface flaw. Therefore, a three-dimensional finite element model, including crack tip elements, was developed to determine the increase in the theoretical infinite plate K value due to the edge effect. The flaw evaluation was based on the guidelines of Appendix A of ASME Section XI. The allowable K values considered adjusted reference temperature (ART) based on cumulative fluence from operation to end of design life, which included a 20-year license renewal period. Because the calculated values of K were less than the allowable values of K, it was concluded that the indication is not expected to become a surface indication during future operation. Discussion on recommendations for RPVs with Upjohn welds, suggested changes to ASME Section XI Paragraph IWB-3610 and a comparison with the RPV flaw database is also provided.

Evaluation of Thermal Distribution in Friction Stir Welding on Dissimilar Materials (Cu-Al) Using Infrared Thermography and Numerical Simulation

2016 ◽  
Vol 1138 ◽  
pp. 113-118
Author(s):  
Monica Iordache ◽  
Eduard Nitu ◽  
Claudiu Badulescu ◽  
Doina Iacomi ◽  
Lia Nicoleta Boţilă ◽  
...  
Keyword(s):  
Friction Stir Welding ◽  
Infrared Thermography ◽  
Three Dimensional ◽  
Welding Process ◽  
Dissimilar Materials ◽  
Element Model ◽  
Fe Model ◽  
Friction Stir ◽  
Solid State Joining ◽  
Joining Process

Friction Stir Welding (FSW) is a solid state joining process realized by the interaction between a non-consumable welding tool that rotates on the contact surfaces of the combined parts. Welding dissimilar materials aluminum and copper by FSW are of great interest because Al and Cu are two most common engineering materials widely used in many industries. This paper presents an investigation concerning the influence of the rotation of the tool on temperatures during the welding process. Also, the welding of copper and aluminum materials by FSW process was simulated using a finite element model. Three-dimensional FE model has been developed in ABAQUS/Explicit using the Coupled Eulerian Lagrangian method, the Johnson–Cook material law and the Coulomb’s Law of friction and was validated by infrared thermography method and thermocouple measurement.

Assessment of the Influence of Welding Parameters on Distortion

2014 ◽  
Vol 597 ◽  
pp. 208-212
Author(s):  
Fábio Renck Locatelli ◽  
Walter Jesus Paucar Casas ◽  
Ricardo Frederico Leuck Filho
Keyword(s):  
Welding Speed ◽  
Three Dimensional ◽  
Welding Process ◽  
Physical And Mechanical Properties ◽  
Element Model ◽  
Welding Parameters ◽  
Welding Sequence ◽  
Dimensional Finite Element ◽  
Definition Of ◽  
Three Dimensional Finite Element

The welding involves the transfer of high localized heat flow, which results in residual stresses in the welded body. The impossibility of relieving these stresses generates welding distortions that become a problem in dimensional setting of welded structures. This study aims to evaluate the influence of some parameters in the welding process in a T-type joint. Due to the complexity of the welded joint and the deposition rate, a three-dimensional finite element model was developed for the solution of the temperature field and distortions. The transient thermal analysis used the Goldak equation for definition of the heat flux transferred to the part. The nonlinear characteristics of the phenomenon as well as the dependence of physical and mechanical properties with the temperature were considered in this work. The parameters studied were the welding speed, welding sequence and cooling time between weld beads. The results suggest that the higher welding speed, the welding sequence forward and back and with cooling interval between beads present themselves as the best parameters for welding with lower distortions.

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