Temperature Distribution In Welding Research Articles

Finite Element Simulation of Weld Bead Geometry and Temperature Distribution during GTA Welding of Modified 9Cr-1Mo Steel and Experimental Validation

AbstractThe thermal analysis of Modified 9Cr-1Mo steel plate during GTA welding is carried out using finite element method employing SYSWELD software. First, the simulation of bead on plate welds for 16 varying process parameter conditions by employing a double ellipsoidal heat source was carried out. Simulated bead on plate weld bead dimensions for the 16 welds were compared with the actual bead dimensions obtained experimentally. Then the simulation of GTA welding of square butt joint on 3 mm thick plates of dimensions 300 × 125 × 3 mm was carried out. The simulated thermal profiles were validated using thermocouple measurements. There was good agreement between the predicted and measured weld bead profiles and thermal cycles for square butt joint. The investigation on the effect of copper back up plate on the peak temperature and the cooling rate has revealed that the peak temperature decreased by 147 °C and the cooling rate increased by 35%.

Numerical Studies on Submerged Arc Welding Process

A quantitative understanding on the effect of the welding conditions on weld joint dimensions and weld thermal cycle is difficult through experimental studies alone. The experimental realization of temperature distribution in the weld pool is proved to be extremely difficult due to the small size of welds, high peak temperature and steep temperature gradients in weld pool. This review deals with the heat transfer and fluid flow analysis to understand the parametric influence of a single wire submerged arc welding (SAW) and multi-wire SAW processes on the weld bead dimensions, temperature and fluid flow distribution in the weldment.

Simulation and Stress Analysis of U-Shaped Seam Welding Process Based on ABAQUS

At present, there is large-scale trend for chemical containers and reaction tower in the industry. In the large-scale equipment, U-shaped weld structure are widely used for splice weld of container wall. In this paper, by ABAQUS software, using plane models, U-shaped seam welding process was simulated which was commonly used in pressure vessels and tower equipment. For welding material part, the calculation use of "dead-actived elements" technique, and the weld material part was divided into finer grid. The calculation model of the plane model was created using CATIA software, the software plug-in software was used to transform the model to directly read the ABAQUS software model. Calculation can be given to each welding temperature distribution and stress distribution. At the same time, the welding process to consider the cooling after welding. Computer simulation gave the overall structure of the stress distribution and strain energy curve.

Measurement of Tool-Workpiece Interface Temperature Distribution in Friction Stir Welding

The objective of this work is to develop an improved temperature measurement system for friction stir welding (FSW). FSW is a solid-state joining process enabling welds with excellent metallurgical and mechanical properties, as well as significant energy consumption and cost savings compared to traditional fusion welding processes. The measurement of temperatures during FSW is needed for process monitoring, heat transfer model verification and process control, but current methods have limitations due to their restricted spatial and temporal resolution. Previous work showed that temperatures at the tool shoulder-workpiece interface can be measured and utilized for closed-loop control of temperature. Adding an additional thermocouple at the tool pin-workpiece interface and performing a calibration of the measurement to gain better insight into the temperature distribution in the weld zone improved the method. Both thermocouples were placed in through holes right at the interface of tool so that the sheaths are in direct contact with the workpiece material. This measurement strategy reveals dynamic temperature variations at the shoulder and the pin within a single rotation of the tool in real-time. It was found that the highest temperatures are at the shoulder interface between the advancing side and the trailing edge of the tool, closer to the advancing side. The temperature distribution was mostly affected by travel speed and the temperature difference within one tool rotation was found to be between 10 °C and 50 °C, depending on the process parameters. The dynamic temperature measurements obtained with the current system are of unmatched resolution, fast, and reliable and are likely to be of interest for both fundamental studies and process control of FSW.

Unstable Temperature Distribution in Friction Stir Welding

In the friction stir welding process, a nonuniform and high generated temperature is undesirable. Unstable temperature and distribution affect thermal and residual stresses along the welding line, thus necessitating mitigation. This paper presents a simple method to prevent significant temperature difference along the welding line and also to help nullifying some defect types associated with this welding, such as end-hole, initial unwelded line, and deformed areas. In the experimental investigation, a heat and force thermocouple and dynamometer were utilized while couple-field thermomechanical models were used to evaluate temperature and its distribution, plastic strain, and material displacement. The suggested method generated uniform temperature distributions. Measurement results are discussed, showing a good correlation with predictions.

基于ABAQUS的U型焊缝焊接过程模拟和应力分析

目前，在工业界，化工容器、反应塔等有大型化的趋势。在大型设备中，容器壁的拼接焊缝广泛采用U型焊缝结构。本文采用ABAQUS软件，使用平面模型，对压力容器和塔类设备中常用的U型焊缝焊接过程进行了模拟。计算中，对于焊接材料部分，采用了单元死活技术，而且划分了更加细密的网格。计算模型是采用CATIA软件建立的平面模型，在该软件的插件中，将模型变换为ABAQUS软件直接读取的软件模型。计算可以给出每道焊接的温度分布和应力分布。同时，焊接过程考虑了焊接后的冷却。在计算模拟后，还给出了整体结构的应力分布和应变能变化曲线。 At present, there is a large-scale trend for chemical containers and reaction tower in the industry. In the large-scale equipment, U-shaped weld structure is widely used for splice weld of container wall. In this paper, by ABAQUS software, using plane models, U-shaped seam welding process was simulated, which was commonly used in pressure vessels and tower equipment. For welding material part, the “dead-actived elements” technique was applied in calculation, and the weld material part was divided into finer grid. The calculation model of the plane model was created using CATIA software, the software plug-in software was used to transform the model to directly read the ABAQUS software model. Calculation can be given to each welding temperature distribution and stress distribution. At the same time, the cooling after welding was considered in the welding process. Computer simulation gave the overall structure of the stress distribution and strain energy curve.

Ultrasonic Welding Simulations for Multiple Layers of Lithium-Ion Battery Tabs

Ultrasonic welding is a solid-state bond created using ultrasonic energy. It has been used in the semiconductor industry for several decades, and more recently, in the automotive industry such as for lithium-ion battery welding. Although there existed numerical simulations for ultrasonic welding, the models were limited to two-layer and like materials stackups. In this study, finite element theories are introduced and simulation procedure is established for multiple sheets and dissimilar metal ultrasonic welding. The procedures require both abaqus/Standard and abaqus/Explicit to simulate the coupled mechanical-thermal phenomena over the entire weld duration with moderate computational cost. The procedure is verified and used to simulate selected specific cases involving multiple sheets and dissimilar materials, i.e., copper and aluminum. The simulation procedure demonstrates its capability to predict welding energy, distortion, and temperature distribution of the workpieces. Case studies of ultrasonic welding simulations for multiple layers of lithium-ion battery tabs are presented. The prediction leads to several innovative ultrasonic welding process designs for improved welding quality.

Study of Multi Pass Welding Temperature Distribution in Dissimilar Steels

An efficient structure design using welding of dissimilar steels is a common strategy in the process and construction industries. This study investigates the temperature distribution in the HAZ due to multi pass welding of an austenitic stainless steel SUS316 pipe to carbon steel S610 plate. A nonlinear transient thermal FE analysis is performed using ANSYS software. An APDL (ANSYS Parametric Design Language) program is developed to define moving double ellipsoidal heat source model, nonlinear thermal properties and thermal boundary conditions. Addition of filler metal is simulated using element death and birth technique. Transient effect of heat and cooling slopes during welding are studied. The present work offers a basis for future prediction of welding residual stresses and distortions in joint between pipe and plate.

Analysis of Temperature and Residual Stress Distribution in Laser Welding for Ta/Mo Lap Joints Using FEM

A nonlinear transient three-dimensional finite element model for the laser welding process is developed to investigate the temperature and residual stress distribution. All the major physical phenomena associated to the laser welding process, including temperature dependent thermo-physical and mechanical properties are taken into account in the model. The heat input to the model is assumed to be a Gaussian heat source. Results show that the temperature distribution of laser welding is consistent with the actual, and along-welding line longitudinal stress and transverse stress are retained in the weld zone after laser welding and cooling to the room temperature.

Studies on Temperature Distribution in Electromagnetic Welding Process

Electromagnetic welding (EMW) is a solid state impact welding technique which uses pulsed electromagnetic field for welding electrically conductive work pieces like aluminum. High velocity of impact created by the electromagnetic force causes the removal of oxide layer from the weld interface. A fully coupled numerical analysis, incorporating the equivalent electric circuit of EMW, electromagnetic field propagation, heat transfer, and dynamic elasto-plastic deformation, has been carried out using LS-DYNA EM module. The numerical simulation results for the EM weld feasibility, deformation pattern, temperature distribution and velocity of impact are reported here and corroborated with the previously published literature. It is observed that the temperature rise is not significant to cause the melting of Al sheets indicating there will not be any intermetallics. Hence, present paper is important for welding dissimilar metals for automobile components. Metallographic studies have also revealed absence of any coarse or columnar grain structures at the weld interface.

Study on the effect of tool profiles on temperature distribution and material flow characteristics in friction stir welding

The present investigation describes a computational fluid dynamics approach to study the effects of friction stir welding tool profiles on the thermal conditions and material flow in welds. The aim is to observe the temperatures of the weld and material flow with respect to different probe profiles. For the modeling purpose, temperature dependent material properties and stick–slip conditions between the tool and work material were incorporated. The results from the model exhibited most of the process characteristics of friction stir welding, such as the difference in temperatures of advancing and retreating sides of the weld, temperature contours ahead and behind the tools along the weld, and flow fields. The thermal condition exhibited temperatures that were close to experimental values and below the melting point of the aluminum alloy.

Theoretical and Experimental Investigation of Transient Temperature Distribution in Friction Stir Welding of AA 7020-T53

Finite element modeling of transient temperature distribution is used to understand physical phenomena occurring during the dwell (penetration) phase and moving of welding tool in friction stir welding (FSW) of 5mm plate made of 7020-T53 aluminum alloy at 1400rpm and 40mm/min.Thermocouples are used in locations near to the pin and under shoulder surface to study the welding tool penetration in the workpiece in advance and retreate sides along welding line in three positions (penetrate (start welding) , mid, pullout (end welding)).Numerical results of ANSYS 12.0 package are compared to experimental data including axial load measurements at different tool rotational speeds (710rpm.900rpm.1120rpm and 1400rpm) Based on the experimental records of transient temperature at several specific locations of thermocouples during the friction stir welding process the temperatures are higher on the advancing side (629.2 oK) than the retreating side (605 oK) along welding line and temperature in the top of workpiece under tool shoulder is higher(645 oK) than bottom (635.79oK). The results of the simulation are in good agreement with that of experimental results. The peak temperature obtained was 70% of the melting point of parent metal.

Modelling of the Heat Flux Density Distribution for Laser Beam Welding

Great interest of the laser beam welding in industry is a new theoretical task, making planning the welding procedure specification and the quality control of welded joints easier. Estimating and calculating the dimensions of a weld pool and temperature distribution near weld mainly concern heat source modelling. In the presented work calculations of welding pool shape and thermal field for cylindrical-powered-normally model of heat source have been presented. Parameters of the model of heat source and weld pool geometry were determined using analytical-numerical calculations. The results of numerical calculations were compared with the experimental data for butt joint made by CO2 laser beam. Comparable results have been observed. Practical recommendations for assumptions of model parameters - the flux density energy distribution of the heat source in case of calculations of the thermal field in the vicinity of a weld pool are given.

Prediction of temperature distribution in dissimilar arc welding of stainless steel to carbon steel

In this work, a three-dimensional model has been proposed to predict temperature distribution and weld-pool shape during dissimilar arc welding of low-carbon steel (CK4) and ferritic stainless steel (AISI 409). The model has been developed using the finite-element software ANSYS, while in the analysis, the effects of process parameters, as well as dilution, in the weld pool have been considered. To verify the predictions, welding experiments were conducted under different welding conditions, and the model results were then compared with the measured weld-pool geometry; a reasonable consistency was observed.

Parametric Study of Welding Temperature Distribution in T-Joint Fillet Weld Using FEM

This paper presents FE simulation of Arc welding process using nonlinear transient thermal analysis to study the effect of process parameters on temperature distributions in T-joint fillet welds. An APDL (ANSYS Parametric Design Language) program is developed to define moving surface heat source model with Gaussian distribution into simulations by using commercially available FE code ANSYS. The transient temperature distribution in fillet weld during welding process are predicted and subsequently validated with published experimental results. Influence of heat energy input, electrode angle, welding speed and plate thickness on temperature distribution was further explored. The present work provides a basis for prediction of welding residual stresses and distortions in fillet joints.

Experiment and numerical simulation in temperature distribution and welding distortion in GMA welding

Experiment and numerical simulation in temperature distribution and welding distortion in GMA welding

Study on welding temperature distribution in thin welded plates through experimental measurements and finite element simulation

The welding temperature distributions in the HAZ were measured using K-type thermocouples in similar and dissimilar thin butt-welded joints which experienced one-pass GTAW welding process. Three dimensional finite element simulations were also implemented to predict the temperature distributions throughout the plates using ABAQUS software. Comparison between experimental and simulation results reveals very good agreement. The results provide good evidence for prediction of the HAZ microstructure considering the fact that the thermocouples have been attached very closely to the weld line, and provide objective cooling slopes. The absence of filler materials in the welded joints is helpful to observe the peak temperature and cooling slope differences in relation with material properties differences.

Study on Mathematical Model of Temperature Field in the Laser Welding Process

From the laser welding actual process, the welding heat source model of laser welding process was established, that is, superposition heat source. According to the knowledge of thermodynamics, the establishment of a welding process, the mathematical model of temperature distribution of laser welding process was obtained by laser welding heat source. Finally, the finite element simulation of welding temperature distribution was used. The simulated results were compared with the analytical results of mathematical model of temperature field, it was proved consistent between simulated results and analytical results, at the same time it can account for the correctness of the mathematical model of temperature field.

Temperature and stress distribution in ultrasonic metal welding—An FEA-based study

In ultrasonic welding, high frequency vibrations are combined with pressure to join two materials together quickly and securely, without producing significant amount of heat. During ultrasonic welding of sheet metal, normal and shear forces act on the parts to be welded and the weld interface. These forces are the result of ultrasonic vibrations of the tool, pressed onto the parts to be welded. In this study a model for the temperature distribution during welding and stress distribution in the horn and welded joints are presented. With the knowledge of the forces that act at the interface it is possible to control weld strength and avoid sonotrode welding (sticking of the sonotrode to the parts). The presented finite element model is capable of predicting the interface temperature and stress distribution during welding and their influences in the work piece, sonotrode and anvil. The study also included the effect of clamping forces, material thickness and coefficient of friction during heat generation at the weld interface.

Local Melting of Glass Material and Its Application to Direct Fusion Welding by Ps-laser Pulses

Fusion welding of glass by picosecond laser pulses is reported where laser energy absorbed by nonlinear absorption is utilized as a heat source for local internal glass melting. Laser pulses with 10ps duration with repetition rates up to 500kHz were focused within borosilicate glass, Schott D263, by an objective lense of NA 0.7. The nonlinear absorptivity of the laser pulses was determined at different pulse energies, repetition rates, traveling velocities and depth of the focus position. The transient and time-averaged temperature distribution in fusion welding of glass was calculated using a thermal conduction model where heat is instantaneously deposited at different repetition rates in the rectangular solid moving linearly at a constant velocity. The experimental dimensions of the melt features agreed well with the calculated values in a velocity range of 1~100mm/s. Excellent seam welding of two glass plates is demonstrated without cracking and thermal distortion. 10ps laser pulses provided higher melting and joining efficiencies than sub-ps pulses due to the higher nonlinear absorptivity by the larger contribution of the avalanche ionization, and also provided the highest efficiencies in the existing fusion welding techniques.