scholarly journals Selected Aspects of the FEM-Based Numerical Modelling of Current Propagation in the Resistance Multispot Cruciform Welding of Bars

2021 ◽  
pp. 7-14
Author(s):  
Mariusz Stępień ◽  
Zygmunt Mikno
Keyword(s):  
Power Supply ◽  
Software Package ◽  
Research Work ◽  
Three Dimensional ◽  
Welding Process ◽  
Welding Current ◽  
Welding Machine ◽  
Dc Power ◽  
Welding Processes

The article presents selected aspects of the FEM-based analysis concerning resistance welding processes performed using multispot welding systems. The analysis was based on a three-spot welding machine used for the joining bars in the cruciform configuration. Both two and three-dimensional modelling was performed as the comparative analysis of two computing software packages, i.e. the commercial ANSYS Mechanical software package and the ARTAP software package, available on an open access basis. The research work involved the determination of current propagation in various welding process configurations as well as the identification of the percentage loss of welding current and power resulting from the bridging of current by neighbouring welds. The article discusses the effect of the method of the power supply and the earthing of the system of electrodes along with the welded material on the manner of current propagation. The analyses presented in the article were performed in relation to the DC power supply (inverter welding machine). Related calculations were performed using averaged (in terms of heat and resistance) material parameters.

Analysis of Arc Welded Thin-Walled Cylinders to Investigate the Effects of Welding Process Parameters on Residual Stresses

2008 ◽  
Vol 575-578 ◽  
pp. 763-768
Author(s):  
Afzaal M. Malik ◽  
Ejaz M. Qureshi ◽  
Naeem Ullah Dar
Keyword(s):  
Residual Stresses ◽  
Process Parameters ◽  
Arc Welding ◽  
Research Work ◽  
Three Dimensional ◽  
Welding Process ◽  
Welding Current ◽  
Element Model ◽  
Welding Parameters ◽  
Thin Walled

The research work presents a computational methodology based on three-dimensional finite element model to simulate the gas tungsten arc welding (GTAW) of thin-walled cylinders. The aim was to study the effects of two basic welding parameters (welding speed and welding current) on weld induced residual stresses. The complex phenomenon of arc welding was numerically solved by sequentially coupled transient, non-linear thermo-mechanical analysis. The accuracy of the numerical model was validated through experiments for temperature distribution and residual stresses. The results reveals that the present simulation strategy can be used as a proper tool to get the optimized welding process parameters and minimize the in service failures of thinwalled structures due to residual stresses.

Determination of Heat Input in Tungsten Inert Gas and Laser Welding of Type Optim 960 QC Structural Steel Using Adams’ Equation for 2-D Heat Distribution

2017 ◽  
Vol 750 ◽  
pp. 45-52
Author(s):  
Sveto Cvetkovski
Keyword(s):  
Laser Welding ◽  
Heat Input ◽  
Arc Welding ◽  
Research Work ◽  
Laser Beam Welding ◽  
Peak Temperature ◽  
Efficiency Coefficient ◽  
Zone Recrystallization ◽  
Welding Processes

The heat input during conventional arc welding processes can be readily calculated knowing the power taken from the power source. The efficiency coefficient can be taken from the appropriate literature standards. Here, the intention of the performed research work was to develop a procedure for determination of heat input in arc and laser welding processes implementing Adams equation - modified Rykalin equation for two dimensional heat distributions (2-D). To realize this idea, it is necessary to determine two characteristic temperatures points in the HAZ with known peak temperature, and to determine distance between them. Implementing measured values for distance in Adams’ equation, heat input in arc welding can be directly determined in arc welded joints.In laser beam welding, the absorption of the beam in the metal is not known, so that the welding heat input cannot be calculated directly, and direct implementation of Adam’s equation is not possible i.e. absorption coefficient has to be determined first, and after that calculation of heat input is possible.The peak temperatures corresponding to specific microstructures can be obtained by performing welding simulation, by the Gleeble 1500 simulator in our case. As one of the peak temperatures, the melting temperature can be used corresponding to the fusion line, so that at least one characteristic peak temperature such as coarse grain zone, fine grin zone, intercritical zone, recrystallization, has to be determined by the simulation.Performed research showed that obtained values for heat input using Adam’s equation correspond pretty well with standard equation for heat input in arc welding.

Study on Drive Characteristic of Multi–Rope Friction Winder Using Functional Virtual Prototyping

2009 ◽  
Vol 628-629 ◽  
pp. 305-310
Author(s):  
Yi Liu ◽  
Guo Ding Chen ◽  
J.S. Li ◽  
Y.J. Xue
Keyword(s):  
Software Package ◽  
3D Model ◽  
Virtual Work ◽  
Virtual Prototyping ◽  
Research Work ◽  
Three Dimensional ◽  
Virtual Work Principle ◽  
Nodal Method ◽  
Hoisting System ◽  
Dynamics Characteristic

The main objective of this study was to model and simulate a reduced three-dimensional (3D) model for researching the hoisting system of a Multi – rope Friction Winder. By introducing the relative nodal method, the simplified dynamic equations have been derived via the virtual work principle and validated on a virtual prototype with the RecurDyn software package. Kinematics and dynamics characteristic date are obtained by computer-aided dynamic simulation of virtual Multi – rope friction winder. The result is in accord with theoretical analysis. The research work will provide a powerful tool and useful method for the design of economic and credible elevator system. The approach can be generalized to analysis other flexible drive fields.

A Comparative Study of AC and MFDC Resistance Spot Welding

2004 ◽  
Author(s):  
Wei Li ◽  
Daniel Cerjanec
Keyword(s):  
Comparative Study ◽  
Resistance Spot Welding ◽  
Spot Welding ◽  
Welding Process ◽  
Welding Current ◽  
Median Frequency ◽  
Resistance Spot ◽  
Secondary Voltage ◽  
Nugget Growth ◽  
Welding Processes

This paper presents a comparative study of the AC and MFDC resistance spot welding process. Two identical welders were used; one with a single phase AC and the other with a median frequency DC weld control. Both welders were instrumented such that the primary and secondary voltage and current could be collected. A nugget growth experiment was conducted to compare the weld size and energy consumption in the AC and MFDC welding processes. It is found that the MFDC process generally produces larger welds with the same welding current. However, this difference is more prominent when the welding current is low. Overall the AC welding process consumes more energy to make a same size weld. The larger the welding current is used, the less efficient the AC process becomes.

Examination of the Welding Processes when Welding of Steel in Protective Gas Atmosphere of Gases with the Application of Modeling and Numerical Simulation

2017 ◽  
Vol 737 ◽  
pp. 133-139
Author(s):  
Helena Kravarikova
Keyword(s):  
Numerical Simulation ◽  
Computational Models ◽  
Three Dimensional ◽  
Welding Process ◽  
Real System ◽  
Temperature Fields ◽  
Software Systems ◽  
Butt Weld ◽  
Protective Gas ◽  
Welding Processes

Modelling and numerical simulation of technological welding processes is the creative experimental method. Simulation replaces a real system computer model. To create the model can be applied to many experiments under predetermined conditions and analysis of the results. The results can be optimized and implemented to a real system. In a relatively short time, it is possible to solve complex processes occurring in the melting phase of the welding process, using the most advanced computer technology. Appropriately selected algorithm of model experiments can help study the course of temperature fields and formation of stresses and strains in solving the problems in the field of welding. The result of thermal and structural tasks of numerical simulation using FEM are the temperature fields, stress fields and strain generated in the process of welding and welded parts during cooling. Procedure of solving the tasks can be applied to any weld shape and any material of welded parts. The results published in the paper were obtained by solving the thermal and stress- strain tasks in the ANSYS program. Modelling and numerical simulation open possibilities for the three dimensional analysis of the phenomena studied. Based on the development of numerical methods and their application, it is possible to create computational models. Their implementation in software systems opens new possibilities for the area of numerical simulation of technological welding processes. The paper described simulation fillet and butt weld made of stainless steel 17242.

Evaluation of the Role of Eddy Current in Resistance Spot Welding

2009 ◽  
Vol 131 (6) ◽  
Author(s):  
M. Abu-Aesh ◽  
Moataza Hindy
Keyword(s):  
Eddy Current ◽  
Resistance Spot Welding ◽  
Spot Welding ◽  
Welding Process ◽  
Welding Current ◽  
Work Piece ◽  
Resistance Spot ◽  
Precise Prediction ◽  
Welding Processes

Extensive work had been conducted on spot-welding due to its rapidly increasing industrial importance. The resistance spot-welding involves complicated phenomena, as several effects are found in the process, e.g., temperature, surface roughness, pressure, and eddy current effects. Most of the work exerted for analyzing the spot-welding process neglect the effect of the eddy current generated during the flow of the huge welding main current through the assembly of electrodes and work sheets. This work presents an analytical method to investigate the generation of eddy current and to determine the total effective welding current in spot-welding. The current distribution on the work sheet when it is fed by a conducting electrode is also investigated. The obtained current formula is based on electromagnetic principles, where a very strong magnetic field is generated in the core of the electrodes as well as in the materials of work sheets due to the flow of very high amperage. The final resultant effective current is the superposition of the electrode welding current and the induced eddy current in the electrode and work piece assembly. The results offer a viable mathematical model, which can be applied for a precise prediction of the effective value of welding current in spot-welding processes, if applied in a comprehensive model including all involved effects.

Numerical Simulation and Investigation of High Frequency Tube Welding Process

2014 ◽  
Vol 698 ◽  
pp. 245-250 ◽  
Author(s):  
Aleksandr Nikanorov ◽  
Egbert Baake ◽  
Jörg Neumeyer
Keyword(s):  
High Frequency ◽  
Numerical Models ◽  
Thermal Analyses ◽  
Three Dimensional ◽  
Thermal Characteristics ◽  
Welding Process ◽  
Practical Experience ◽  
Time Step ◽  
Tube Welding ◽  
Welding Processes

Welding processes and installations used nowadays are mainly developed on practical experience and analytical calculations. Nevertheless, high frequency induction tube welding is a very complex three-dimensional dynamic process, where the electromagnetic and thermal characteristics are distributed not only in space but in time as well. A more profound detailed investigation of the induction tube welding process can be only done by numerical modeling. Full and local three-dimensional transient numerical models of induction tube welding process with continuous movement of the welded tube have been developed and tested. Coupled electromagnetic and thermal analyses are carried out at each time step of simulation for correction of temperature dependent material properties. Voltage or current of the induction coil can be individually input into electromagnetic analysis at each time step. This approach allows simulating “quasi” steady-state and transient operation modes.

Residual Stresses Evaluation on Radial Friction Welded Joints

2005 ◽  
Author(s):  
Rosa Irene Terra Pinto ◽  
Telmo Roberto Strohaecker
Keyword(s):  
Residual Stresses ◽  
Friction Welding ◽  
Deformation Gradient ◽  
Welding Process ◽  
Hole Drilling ◽  
Welding Parameters ◽  
Hole Drilling Method ◽  
Joint Quality ◽  
Welding Processes

The Radial Friction Welding (RFW) is a solid-state welding process in which two long elements of several metallic alloys can be joined, without the occurrence of common problems to the conventional welding processes that include fusion. During friction welding the temperature evolution is directly related with the deformation gradient, and these fields govern the joint properties. In this work, the finite element method was used to solve the full coupled termomechanical problem in order to determine the deformation and the stress fields and the variation of the temperature during RFW process. The simulation of the RFW process permitted to establish the influence of the welding parameters, like rotation and approximation speed, on the joint quality. Furthermore, the knowledge of the temperature gradient and cooling rates allowed the prediction of the resulting microestruture and determination of the level of residual stresses of the joint. To verify the analytical results the determination of the residual stresses was accomplished by the hole drilling method in several points along the perimeter of two welded workpieces.

scholarly journals Conversion of a Conventional Lathe Machine into a Friction Welding Machine and Performing Some Experimental Tests for its Operational Feasibility

2021 ◽  
Vol 40 (3) ◽  
pp. 545-555
Author(s):  
Kamran Shah ◽  
Hassan Khurshid ◽  
Izhar Ul Haq ◽  
Nauman Khurram ◽  
Zeeshan Ali
Keyword(s):  
Friction Welding ◽  
Applied Pressure ◽  
Welding Process ◽  
Dissimilar Materials ◽  
Experimental Tests ◽  
Cost Effective ◽  
High Productivity ◽  
Welding Machine ◽  
Lathe Machine ◽  
Welding Processes

In today’s manufacturing environment, there is always a need to use cost effective methods and materials for production purposes. Friction welding is one of such method that offers cost effectiveness and high productivity rate as compared to other similar welding processes. Friction welding process has been used widely in the manufacturing world. It is an adjustable and tolerant process that can join most engineering materials. It is a well-established welding process that can produce good quality weldment between similar and dissimilar materials. Due to this flexibility of use of different materials, it has been used in many applications such as aerospace, automotive and other related manufacturing industries etc. The main objective of this research is to study possibility of doing friction-welding on a typical lathe machine instead of doing it on a friction welding machine and also to check the reliability of the welded joint. Conventional Lathe machine was converted into a friction-welding machine by adopting a systematic procedure. The fixture of the attachment was designed, manufactured and installed and different parameters such as applied pressure and spindle rpm were tested in order to achieve the welding joint by friction. The materials used for welding were Stainless Steel 070M20 and Aluminum 2011-T3.

scholarly journals Metode Elektrooptis sebagai Pendeteksi Radikal Bebas dan Prospek untuk Evaluasi Total Mutu Minyak Goreng

2016 ◽  
Vol 3 (01) ◽  
pp. 72 ◽  
Author(s):  
K Sofjan Firdausi ◽  
Heri Sugito ◽  
Ria Amitasari ◽  
Sri Murni
Keyword(s):  
Free Radicals ◽  
High Voltage ◽  
Power Supply ◽  
Room Temperature ◽  
Oil Quality ◽  
Relative Number ◽  
Standard Methods ◽  
Dc Power ◽  
Frying Oil Quality

<span>One main problem of standard methods for determination of frying oil quality is various <span>parameter of indicators with their various wide of methods or equipments. In this research we <span>proposed a new method for determination of oil quality using single electrooptics parameter to <span>replace previous indicators. The samples used in the experiment were various conditions of <span>palm oils from the same brand. The level of oil quality was proposed by the value of <span>2<span>, which <span>represents as the relative number of free radicals produced in the sample. The change of <span>polarization was measured by the value of as the samples were induced by an external <span>electric field using high voltage dc power supply. At room temperature of 28 C electrooptics <span>method seems capable to detect free radicals and to distinguish all kinds of palm oils. This <span>method has an opportunity to provide a single parameter of oil quality and an evaluator of <span>halal or authentic food from fats.</span></span></span></span></span></span></span></span></span></span><br /></span></span></span>

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