Numerical Simulation of Temperature Fields by Welding of Ti-Al Alloys Applying Volumetric Heat Source

2014 ◽  
Vol 887-888 ◽  
pp. 1280-1283 ◽  
Author(s):  
Eva Babalová ◽  
Mária Behúlová
Keyword(s):  
Numerical Simulation ◽  
Heat Source ◽  
Laser Beam Welding ◽  
Welding Process ◽  
Temperature Fields ◽  
Transient Temperature ◽  
Al Alloy ◽  
Butt Joints ◽  
Butt Weld ◽  
Volumetric Heat Source

Transient temperature fields during formation of dissimilar butt joints of Ti-Al alloy plates by laser welding process were investigated by numerical simulation. Gaussian volumetric heat source was applied to model the heat input to the weld. For verification of the developed simulation model and results of numerical simulation, Ti-Al butt weld joints were produced by TruDisk 4002 disk laser. During experiments, the temperatures were measured by thermocouples and subsequently compared with results of FEM analysis. Based on the results of preliminary numerical calculations and experimental tests, the parameters of the laser beam welding for production of dissimilar Ti-Al butt joints will be optimized using FEM simulations in the program code ANSYS.

Numerical Simulation of the Influence of Laser Power on the Temperature Distribution during Dissimilar Welding of Ti-Al Alloy Plates

2016 ◽  
Vol 826 ◽  
pp. 77-81
Author(s):  
Eva Babalová ◽  
Mária Behúlová
Keyword(s):  
Numerical Simulation ◽  
Temperature Distribution ◽  
Laser Power ◽  
Laser Beam Welding ◽  
Fem Simulation ◽  
Temperature Fields ◽  
Dissimilar Welding ◽  
Transient Temperature ◽  
Al Alloy ◽  
Titanium Grade

The paper deals with the design and testing of laser power for laser beam welding of titanium Grade 2 and EN AW 5754 aluminium alloy plates. Transient temperature fields during formation of dissimilar butt joints of Ti-Al alloy plates were investigated by FEM simulation using the program code ANSYS. Moving Gaussian volumetric heat source was applied to model the heat input to the weld. The influence of laser power on the temperature distribution in welded materials and parameters of the weld pool were evaluated. Based on the results of numerical simulation, the suitable laser power was suggested for the real experiments of Ti–Al dissimilar laser welding using the TruDisk 4002 disk laser.

scholarly journals Thermal Finite Element Modelling of the Laser Beam Welding of Tailor Welded Blanks through an Equivalent Volumetric Heat Source

2021 ◽  
Author(s):  
Vito Busto ◽  
Donato Coviello ◽  
Andrea Lombardi ◽  
Mariarosaria De Vito ◽  
Donato Sorgente
Keyword(s):  
Finite Element ◽  
Heat Source ◽  
Numerical Models ◽  
Laser Beam Welding ◽  
Welding Process ◽  
Butt Joint ◽  
Volumetric Heat Source ◽  
Tailor Welded Blanks ◽  
Mechanical Models ◽  
Physical Phenomena

Abstract In last decades, several numerical models of the keyhole laser welding process were developed in order to simulate the joining process. Most of them are sophisticated multiphase numerical models tempting to include all the several different physical phenomena involved. However, less computationally expensive thermo-mechanical models that are capable of satisfactorily simulating the process were developed as well. Among them, a moving volumetric equivalent heat source, whose dimensions are calibrated on experimental melt pool geometries, can estimate some aspects of the process using a Finite Element Method (FEM) modelling with no need to consider fluid flows. In this work, a double-conical volumetric heat source is used to arrange a combination of two half hourglass-like shapes with different dimensions each other. This particular arrangement aims to properly assess the laser joining of a Tailor Welded Blank (TWB) even in case of butt joint between sheets of different thicknesses. Experiments of TWBs made of 22MnB5 steel sheets were conducted in both equal and different thicknesses configurations in order to validate the proposed model. The results show that the model can estimate in a satisfactory way the shape and dimensions of the fused zone in case of TWB made of sheets with different thickness.

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.

Temperature Profile and its Effect on Hardness Numbers of a Mild Steel Butt Weld

2019 ◽  
Author(s):  
Qin Ma
Keyword(s):  
Heat Source ◽  
Mild Steel ◽  
Temperature Profile ◽  
Arc Welding ◽  
Rapid Heating ◽  
Welding Process ◽  
Fusion Welding ◽  
Transient Temperature ◽  
Shielded Metal Arc Welding ◽  
Butt Weld

Abstract Fusion welding of steel joints is common through history of industrial applications. Among those, Shielded Metal Arc Welding (SMAW) and Gas Tungsten Arc Welding (GTAW) are most common. Fusion welding process comprises of rapid heating and cooling cycles. Each cycle produces a non-uniform and transient temperature distribution and causes rapid thermal expansion followed by thermal contraction. Thus plastic deformation and thermal residual stresses can be induced in a welded joint when it cools down gradually to room temperature. In this study, temperature profiles of a hand-weld mild steel butt weld are analyzed by means of the finite element method (FEM) through ANSYS Mechanical APDL The moving heat source is simulated using the Gaussian distribution heat source model. A parametric study was then performed to evaluate the importance of certain key process parameters that affect the quality of a weldment. The effects of temperature profile on hardness numbers inside and away from the heat affected zone (HAZ) are discussed. It was found that the residual stress results obtained from the simulation agree with the distribution of hardness numbers tested on the weldment sample.

Evaluation by FEM of the Influence of the Preheating and Post-Heating Treatments on Residual Stresses in Welding

2014 ◽  
Vol 627 ◽  
pp. 93-96 ◽  
Author(s):  
Raffaele Sepe ◽  
Enrico Armentani ◽  
Giuseppe Lamanna ◽  
Francesco Caputo
Keyword(s):  
Temperature Distribution ◽  
Residual Stresses ◽  
Gas Metal Arc Welding ◽  
Welding Process ◽  
Element Model ◽  
Butt Joint ◽  
Temperature Fields ◽  
Heating Process ◽  
Butt Weld ◽  
Metal Arc Welding

During the last few years various experimental destructive and non-destructive methods were developed to evaluate residual stresses. However it is impossible to obtain a full residual stress distribution in welded structures by means of experimental methods. This disadvantage can be solved by means of computational analysis which allows to determine the whole stress and strain fields in complex structures. In this paper the temperature distribution and residual stresses were determined in a single-pass butt joint welded by GMAW (Gas Metal Arc Welding) process by finite element model (FEM). A 3D finite parametric element model has been carried out to analyze temperature distribution in butt weld joints and thermo-mechanical analyses were performed to evaluate resulting residual stresses. Temperature fields have been investigated by varying an initial preheating treatment. Moreover the technique of “element birth and death” was adopted to simulate the process of filler metal addition The high stresses were evaluated, with particular regard to fusion zone and heat affected zone. The influence of preheating and post-heating treatment on residual stresses was investigated. The residual stresses decrease when preheating temperature increases. The maximum value of longitudinal residual stresses without pre-heating can be reduced about 12% and 38% by using the preheating and post-heating process respectively.

Nonlinear Optimization Methods for the Determination of Heat Source Model Parameters

2016 ◽  
Vol 879 ◽  
pp. 2008-2013
Author(s):  
Udo Hartel ◽  
Alexander Ilin ◽  
Steffen Sonntag ◽  
Vesselin Michailov
Keyword(s):  
Experimental Data ◽  
Heat Source ◽  
Parameter Identification ◽  
Nonlinear Optimization ◽  
Laser Beam Welding ◽  
Source Model ◽  
Transient Temperature ◽  
Surface Model ◽  
Model Parameters ◽  
Heat Source Model

In this paper the technique of parameter identification is investigated to reconstruct the 3D transient temperature field for the simulation of laser beam welding. The reconstruction bases on volume heat source models and makes use of experimental data. The parameter identification leads to an inverse heat conduction problem which cannot be solved exactly but in terms of an optimal alignment of the simulation and experimental data. To solve the inverse problem, methods of nonlinear optimization are applied to minimize a problem dependent objective function.In particular the objective function is generated based on the Response Surface Model (RSM) technique. Sampling points on the RSM are determined by means of Finite-Element-Analysis (FEA). The scope of this research paper is the evaluation and comparison of gradient based and stochastic optimization algorithms. The proposed parameter identification makes it possible to determine the heat source model parameters in an automated way. The methodology is applied on welds of dissimilar material joints.

scholarly journals Assessment of the Effect of Laser Welding on the Properties and Structure of TMCP Steel Butt Joints

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1312 ◽  
Author(s):  
Jacek Górka
Keyword(s):  
Laser Beam ◽  
Welded Joints ◽  
Research Work ◽  
Laser Beam Welding ◽  
Welding Process ◽  
Tensile Tests ◽  
Carbon Equivalent ◽  
Quality Level ◽  
Butt Joints ◽  
Plastic Properties

The research work and related tests aimed to identify the effect of filler metal-free laser beam welding on the structure and properties of butt joints made of steel 700MC subjected to the TMCP (thermo-mechanically controlled processed) process. The tests involved 10-mm thick welded joints and a welding linear energy of 4 kJ/mm and 5 kJ/mm. The inert gas shielded welding process was performed in the flat position (PA) and horizontal position (PC). Non-destructive testing enabled classification of the tested welded joints as representing the quality level B in accordance with the requirements set out in standard 13919-1. Destructive tests revealed that the tensile strength of the joints was 5% lower than S700MC steel. The results of tensile tests and changes in structure were referred to joints made using the MAG (Metal Active Gas) method. The tests of thin films performed using a high-resolution scanning transmission electron microscope revealed that, during laser beam welding, an increase in dilution was accompanied by an increase in the content of alloying microadditions titanium and niobium, particularly in the fusion area. A significant content of hardening phases in the welded joint during cooling led to significant precipitation hardening by fine-dispersive (Ti,Nb)(C,N) type precipitates being of several nanometres in size, which, in turn, resulted in the reduction of plastic properties. An increase in the concentration of elements responsible for steel hardening, i.e., Ti and Nb, also contributed to reducing the weld toughness below the acceptable value, which amounts to 25 J/cm2. In cases of S700MC, the analysis of the phase transformation of austenite exposed to welding thermal cycles and the value of carbon equivalent cannot be the only factors taken into consideration when assessing weldability.

Study on Welding Deformations of Shipboard of Container Vessel

2011 ◽  
Vol 488-489 ◽  
pp. 218-221
Author(s):  
Hong Li ◽  
Da Lu Qiu ◽  
Guang Lei Li ◽  
Hui Long Ren
Keyword(s):  
Heat Flux ◽  
Heat Source ◽  
Three Dimensional ◽  
Temperature Fields ◽  
Transient Temperature ◽  
Plastic Strains ◽  
Out Of Plane ◽  
Inherent Strain ◽  
Nonlinear Behaviors ◽  
Plane Deformations

Residual plastic strains of the shipboard are the product of nonlinear behaviors during welding. Deformations of a welded shipboard injure the beauty of appearance of the ship, cause errors during the assembly of the shipboard and reduce the strength of the ship. Residual welding deformations of shipboard of a container vessel are studied in this paper. Nonlinear three dimensional transient temperature fields are analyzed by FEM first. The heat source is modeled as a moving heat flux following a Gaussian distribution. Then, applying the equivalent loads induced by the inherent strain on the shipboard, the final in-plane shrinkage and out-of-plane deformations are calculated. Being compared with the experimental results of deformations, the simulated results show mostly conformity.

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