The Experts below are selected from a list of 2634 Experts worldwide ranked by ideXlab platform
Dean Deng - One of the best experts on this subject based on the ideXlab platform.
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effects of pass arrangement on Angular Distortion residual stresses and lamellar tearing tendency in thick plate t joints of low alloy steel
Journal of Materials Processing Technology, 2019Co-Authors: Chaohua Zhang, Suo Li, Long Hu, Dean DengAbstract:Abstract Three thick-plate T-joints with different pass arrangements were fabricated using low alloy steel. Experiments were conducted to measure the Angular Distortion and residual stress distribution of these T-joints. Based on ABAQUS code, a sequentially coupled thermal-mechanical finite element method considering moving heat source was developed to model the welding deformation and residual stress distribution of the multi-pass T-joints. The evolution of the Angular Distortion and stress distribution during welding process of the three T-joints was analyzed by means of numerical simulation. The peak stress distribution in the thickness direction of the flange during the entire welding process was examined based on the simulation results, and the lamellar tearing tendency of the T-joints was investigated. Among the three pass arrangements, the pass arrangement that welding passes are attached to the flange with surfacing welding produces the minimum Angular Distortion and has the lowest tendency of lamellar tearing for thick-plate T-joints.
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controlling Angular Distortion in high strength low alloy steel thick plate t joints
Journal of Materials Processing Technology, 2019Co-Authors: Chaohua Zhang, Suo Li, Yifeng Wang, Dean DengAbstract:Abstract Both numerical approach and experimental method were employed to investigate Angular Distortion and welding residual stress of thick-plate multi-pass T-joints made of high strength low alloy steel. The efficiency of controlling Angular Distortion by the structural restraint method and the presetting method was quantitatively examined based on the simulation results and the experimental measurements. The structural restraint method can reduce Angular Distortion of the T-joint by 73%, while the presetting method can almost completely eliminate the Angular Distortion through setting an appropriate initial presetting. The structural restraint method can slightly mitigate the final welding residual stress, and the presetting method has a negligible influence on the welding residual stress distribution.
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determination of welding deformation in fillet welded joint by means of numerical simulation and comparison with experimental measurements
Journal of Materials Processing Technology, 2007Co-Authors: Dean Deng, Wei Liang, Hidekazu MurakawaAbstract:Abstract Fillet weld is the most common weld type used in the fabrication of structural members in shipbuilding, automobile and other industries. Fillet-welded joints usually suffer from various welding deformation patterns, such as longitudinal shrinkage, transverse shrinkage, Angular Distortion and longitudinal bending. Welding deformation has negative effects on fabrication accuracy, external appearance and various strengths of the welded structures. In this study, experiments are performed to investigate the characteristics of welding deformation in the fillet-welded joint. In order to precisely predict welding deformation by numerical method, a 3-D thermal elastic plastic finite element computational procedure is developed. The simulated results are in a good agreement with the experimental measurements. The influence on welding deformation of the flange thickness is investigated by experiment and numerical simulation. In addition, the generation mechanism of Angular Distortion is clarified through numerical simulation.
Masahito Mochizuki - One of the best experts on this subject based on the ideXlab platform.
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Effect of Heat Input Condition on Reduction of Angular Distortion by Transformation Expansion of Weld Metals
Quarterly Journal of The Japan Welding Society, 2020Co-Authors: Yoshiki Mikami, Masahito Mochizuki, Masao ToyodaAbstract:The effect of heat input parameter on residual Angular Distortion and reduction by transformation expansion of weld metals was investigated by means of numerical simulation. The combinations of heat input Q and plate thickness h were varied to change the heat input parameter Q/h2. Consequently, the residual Angular Distortion could be parameterized by the heat input parameter. On the other hand, the reduction of the Angular Distortion by the transformation expansion was not parameterized by heat input parameter. A parameter b/h, ratio of penetration depth to plate thickness was proposed to consider the effect of welding condition on the reduction of Angular Distortion. Reduction of Angular Distortion was linearly proportional to the ratio of the penetration depth to the plate thickness (b/h).
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temperature distribution effect on relation between welding heat input and Angular Distortion
Science and Technology of Welding and Joining, 2017Co-Authors: Shigetaka Okano, H Tsuji, Masahito MochizukiAbstract:Conventional and activated tungsten inert gas (TIG) welding were conducted under the same welding conditions in an experiment to compare the weld penetration, temperature distribution and Angular Distortion. The results showed that the quantities of heat input per unit welding length were almost the same, but the shapes of the weld penetration and heat-affected zones changed drastically. The difference in Angular Distortion between conventional and activated TIG welding was strongly dependent on the thickness of the welded plate. A Distortion analysis was developed by considering convective heat transfer in the weld pool to obtain a more detailed understanding of the temperature distribution effect on the relation between welding heat input and Angular Distortion. The resulting distinguishable curves for conventional and activated TIG welding, which can lead to the thickness dependence of differences in Angular Distortion, showed the traditional relation between the heat input parameter and the Angular di...
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study on prevention of Angular Distortion in fillet welded t joint by welding with a trailing reverse side gas heating
Welding International, 2016Co-Authors: Yuki Kotani, Shigetaka Okano, Shinji Kobayashi, Tadahisa Tsuyama, Masahito MochizukiAbstract:AbstractReduction or control of Angular Distortion without additional processes is demanded because it takes a lot of time and effort to correct the Angular Distortion of fillet-welded T-joints. In this study, the reduction or control of Angular Distortion of both sides of a fillet-welded T-joint by welding with trailing reverse-side gas heating was investigated through a welding experiment and its numerical simulation. First, the effect of gas heating position and intensity on the reduction in Angular Distortion was experimentally investigated using a gas burner. The results showed that Angular Distortion became smallest when reverse-side heating using the gas burner was located 50 mm backward of the welding torch. Also, the concentrated gas flame with increased propane and oxygen gas flow was effective for reducing Angular Distortion. It was clarified that the Angular Distortion could be controlled completely with an appropriate reverse-side gas heating condition. Next, the numerical simulation model of...
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a discussion of the relationship between heat input parameter and Angular Distortion by considering moving heat source effect
Welding International, 2014Co-Authors: Shigetaka Okano, Masahito Mochizuki, Kazunori Matsushita, Masao ToyodaAbstract:In recent years, it has become much more necessary to control or reduce weld Distortion, which has negative influences on structural integrity, without loss of manufacturing efficiency. Higher accurate prediction of weld Distortion brings in one of the contributions for improvement of manufacturing efficiency. Commonly, Angular Distortion, which is controlled by temperature distribution along the direction of plate thickness, is controlled by heat input parameter (Qnet/h2). However, it is also known that there are several concerns against applicability of conventional heat input parameter for prediction of Angular Distortion. One of the concerns is the effect of welding speed. This is because the conventional heat input parameter is derived from welding thermal conduction theory without considering moving of the weld heat source. Actually, a pre-study by experiment about the effect of welding conditions, including welding speed, on Angular Distortion has shown that Angular Distortion is not always control...
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experimental study on relationship between heat parameter and Angular Distortion
Welding International, 2014Co-Authors: Shigetaka Okano, Masahito Mochizuki, Masao Toyoda, Kazunori Matsushita, Tomoyuki UeyamaAbstract:It is well known that weld residual stress and Distortion should be controlled appropriately for structural integrity. Recently, it has become much more necessary to control weld Distortion to highly improve manufacturing efficiency. Various studies on control of weld Distortion had been conducted based on clarification of influential dominant factors for that. The influential dominant factors had been studied from a viewpoint of temperature distribution in plate thickness section. Without considering moving the weld heat source, the temperature distribution is controlled by weld heat input (Qnet) per weld length. Angular Distortion, which is controlled by temperature distribution along the direction of plate thickness (h), is controlled by heat input parameter (Qnet/h2). However, it has recently become known that the conventional results cannot be applied to all welding processes because such processes are becoming more diversified. It is significant for more accurate control of Angular Distortion to inv...
Masao Toyoda - One of the best experts on this subject based on the ideXlab platform.
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Effect of Heat Input Condition on Reduction of Angular Distortion by Transformation Expansion of Weld Metals
Quarterly Journal of The Japan Welding Society, 2020Co-Authors: Yoshiki Mikami, Masahito Mochizuki, Masao ToyodaAbstract:The effect of heat input parameter on residual Angular Distortion and reduction by transformation expansion of weld metals was investigated by means of numerical simulation. The combinations of heat input Q and plate thickness h were varied to change the heat input parameter Q/h2. Consequently, the residual Angular Distortion could be parameterized by the heat input parameter. On the other hand, the reduction of the Angular Distortion by the transformation expansion was not parameterized by heat input parameter. A parameter b/h, ratio of penetration depth to plate thickness was proposed to consider the effect of welding condition on the reduction of Angular Distortion. Reduction of Angular Distortion was linearly proportional to the ratio of the penetration depth to the plate thickness (b/h).
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a discussion of the relationship between heat input parameter and Angular Distortion by considering moving heat source effect
Welding International, 2014Co-Authors: Shigetaka Okano, Masahito Mochizuki, Kazunori Matsushita, Masao ToyodaAbstract:In recent years, it has become much more necessary to control or reduce weld Distortion, which has negative influences on structural integrity, without loss of manufacturing efficiency. Higher accurate prediction of weld Distortion brings in one of the contributions for improvement of manufacturing efficiency. Commonly, Angular Distortion, which is controlled by temperature distribution along the direction of plate thickness, is controlled by heat input parameter (Qnet/h2). However, it is also known that there are several concerns against applicability of conventional heat input parameter for prediction of Angular Distortion. One of the concerns is the effect of welding speed. This is because the conventional heat input parameter is derived from welding thermal conduction theory without considering moving of the weld heat source. Actually, a pre-study by experiment about the effect of welding conditions, including welding speed, on Angular Distortion has shown that Angular Distortion is not always control...
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experimental study on relationship between heat parameter and Angular Distortion
Welding International, 2014Co-Authors: Shigetaka Okano, Masahito Mochizuki, Masao Toyoda, Kazunori Matsushita, Tomoyuki UeyamaAbstract:It is well known that weld residual stress and Distortion should be controlled appropriately for structural integrity. Recently, it has become much more necessary to control weld Distortion to highly improve manufacturing efficiency. Various studies on control of weld Distortion had been conducted based on clarification of influential dominant factors for that. The influential dominant factors had been studied from a viewpoint of temperature distribution in plate thickness section. Without considering moving the weld heat source, the temperature distribution is controlled by weld heat input (Qnet) per weld length. Angular Distortion, which is controlled by temperature distribution along the direction of plate thickness (h), is controlled by heat input parameter (Qnet/h2). However, it has recently become known that the conventional results cannot be applied to all welding processes because such processes are becoming more diversified. It is significant for more accurate control of Angular Distortion to inv...
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effect of welding conditions on reduction in Angular Distortion by welding with trailing heat sink
Science and Technology of Welding and Joining, 2012Co-Authors: Shigetaka Okano, Masahito Mochizuki, Masao Toyoda, Tomoyuki UeyamaAbstract:AbstractThe effectiveness of welding with a trailing heat sink in reducing the Angular Distortion of a weld has been experimentally investigated with focus on the cooling position. A numerical model of welding with a trailing heat sink is constructed through the comparison of measured values of weld penetration, thermal cycles and Angular Distortion with those calculated. On the basis of this model, the effect of welding heat input conditions on the reduction in Angular Distortion is discussed to evaluate the versatility of welding with a trailing heat sink. The results indicate that the choice of an appropriate cooling position behind the welding heat source is essential for the effective reduction in Angular Distortion. The reduction in Angular Distortion by the heat sink at the appropriate cooling position increases with the heat input parameter Qnet/h, where Qnet is the weld heat input and h is the thickness of the plate.
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effect of weld heat input conditions on reduction of Angular Distortion by heat sink welding
Quarterly Journal of The Japan Welding Society, 2011Co-Authors: Shigetaka Okano, Masahito Mochizuki, Masao Toyoda, Tomoyuki UeyamaAbstract:In recent years, in-process control welding for reducing weld Distortion and residual stress is much more required from a view point of improving manufacturing efficiency. In-process control welding by additional cooling has been proposed as one of techniques for reducing weld Distortion and residual stress. It has already been partially applied for thin-plate structure in industry. In order to extend the range of application of in-process control welding by additional cooling in the future, further studies are required. Firstly in this study, reduction of Angular Distortion by heat-sink welding is experimentally discussed. Based on the experimental results, effect of welding conditions on reduction of Angular Distortion by heat-sink welding is investigated by thermal elastic-plastic analysis. It is concluded that Angular Distortion is reduced by additional cooling with the appropriate cooling position, and the effect of welding conditions on reduction of Angular Distortion are clarified by associated with heat input parameter.
Chaohua Zhang - One of the best experts on this subject based on the ideXlab platform.
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effects of pass arrangement on Angular Distortion residual stresses and lamellar tearing tendency in thick plate t joints of low alloy steel
Journal of Materials Processing Technology, 2019Co-Authors: Chaohua Zhang, Suo Li, Long Hu, Dean DengAbstract:Abstract Three thick-plate T-joints with different pass arrangements were fabricated using low alloy steel. Experiments were conducted to measure the Angular Distortion and residual stress distribution of these T-joints. Based on ABAQUS code, a sequentially coupled thermal-mechanical finite element method considering moving heat source was developed to model the welding deformation and residual stress distribution of the multi-pass T-joints. The evolution of the Angular Distortion and stress distribution during welding process of the three T-joints was analyzed by means of numerical simulation. The peak stress distribution in the thickness direction of the flange during the entire welding process was examined based on the simulation results, and the lamellar tearing tendency of the T-joints was investigated. Among the three pass arrangements, the pass arrangement that welding passes are attached to the flange with surfacing welding produces the minimum Angular Distortion and has the lowest tendency of lamellar tearing for thick-plate T-joints.
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controlling Angular Distortion in high strength low alloy steel thick plate t joints
Journal of Materials Processing Technology, 2019Co-Authors: Chaohua Zhang, Suo Li, Yifeng Wang, Dean DengAbstract:Abstract Both numerical approach and experimental method were employed to investigate Angular Distortion and welding residual stress of thick-plate multi-pass T-joints made of high strength low alloy steel. The efficiency of controlling Angular Distortion by the structural restraint method and the presetting method was quantitatively examined based on the simulation results and the experimental measurements. The structural restraint method can reduce Angular Distortion of the T-joint by 73%, while the presetting method can almost completely eliminate the Angular Distortion through setting an appropriate initial presetting. The structural restraint method can slightly mitigate the final welding residual stress, and the presetting method has a negligible influence on the welding residual stress distribution.
Shigetaka Okano - One of the best experts on this subject based on the ideXlab platform.
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temperature distribution effect on relation between welding heat input and Angular Distortion
Science and Technology of Welding and Joining, 2017Co-Authors: Shigetaka Okano, H Tsuji, Masahito MochizukiAbstract:Conventional and activated tungsten inert gas (TIG) welding were conducted under the same welding conditions in an experiment to compare the weld penetration, temperature distribution and Angular Distortion. The results showed that the quantities of heat input per unit welding length were almost the same, but the shapes of the weld penetration and heat-affected zones changed drastically. The difference in Angular Distortion between conventional and activated TIG welding was strongly dependent on the thickness of the welded plate. A Distortion analysis was developed by considering convective heat transfer in the weld pool to obtain a more detailed understanding of the temperature distribution effect on the relation between welding heat input and Angular Distortion. The resulting distinguishable curves for conventional and activated TIG welding, which can lead to the thickness dependence of differences in Angular Distortion, showed the traditional relation between the heat input parameter and the Angular di...
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study on prevention of Angular Distortion in fillet welded t joint by welding with a trailing reverse side gas heating
Welding International, 2016Co-Authors: Yuki Kotani, Shigetaka Okano, Shinji Kobayashi, Tadahisa Tsuyama, Masahito MochizukiAbstract:AbstractReduction or control of Angular Distortion without additional processes is demanded because it takes a lot of time and effort to correct the Angular Distortion of fillet-welded T-joints. In this study, the reduction or control of Angular Distortion of both sides of a fillet-welded T-joint by welding with trailing reverse-side gas heating was investigated through a welding experiment and its numerical simulation. First, the effect of gas heating position and intensity on the reduction in Angular Distortion was experimentally investigated using a gas burner. The results showed that Angular Distortion became smallest when reverse-side heating using the gas burner was located 50 mm backward of the welding torch. Also, the concentrated gas flame with increased propane and oxygen gas flow was effective for reducing Angular Distortion. It was clarified that the Angular Distortion could be controlled completely with an appropriate reverse-side gas heating condition. Next, the numerical simulation model of...
-
a discussion of the relationship between heat input parameter and Angular Distortion by considering moving heat source effect
Welding International, 2014Co-Authors: Shigetaka Okano, Masahito Mochizuki, Kazunori Matsushita, Masao ToyodaAbstract:In recent years, it has become much more necessary to control or reduce weld Distortion, which has negative influences on structural integrity, without loss of manufacturing efficiency. Higher accurate prediction of weld Distortion brings in one of the contributions for improvement of manufacturing efficiency. Commonly, Angular Distortion, which is controlled by temperature distribution along the direction of plate thickness, is controlled by heat input parameter (Qnet/h2). However, it is also known that there are several concerns against applicability of conventional heat input parameter for prediction of Angular Distortion. One of the concerns is the effect of welding speed. This is because the conventional heat input parameter is derived from welding thermal conduction theory without considering moving of the weld heat source. Actually, a pre-study by experiment about the effect of welding conditions, including welding speed, on Angular Distortion has shown that Angular Distortion is not always control...
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experimental study on relationship between heat parameter and Angular Distortion
Welding International, 2014Co-Authors: Shigetaka Okano, Masahito Mochizuki, Masao Toyoda, Kazunori Matsushita, Tomoyuki UeyamaAbstract:It is well known that weld residual stress and Distortion should be controlled appropriately for structural integrity. Recently, it has become much more necessary to control weld Distortion to highly improve manufacturing efficiency. Various studies on control of weld Distortion had been conducted based on clarification of influential dominant factors for that. The influential dominant factors had been studied from a viewpoint of temperature distribution in plate thickness section. Without considering moving the weld heat source, the temperature distribution is controlled by weld heat input (Qnet) per weld length. Angular Distortion, which is controlled by temperature distribution along the direction of plate thickness (h), is controlled by heat input parameter (Qnet/h2). However, it has recently become known that the conventional results cannot be applied to all welding processes because such processes are becoming more diversified. It is significant for more accurate control of Angular Distortion to inv...
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effect of welding conditions on reduction in Angular Distortion by welding with trailing heat sink
Science and Technology of Welding and Joining, 2012Co-Authors: Shigetaka Okano, Masahito Mochizuki, Masao Toyoda, Tomoyuki UeyamaAbstract:AbstractThe effectiveness of welding with a trailing heat sink in reducing the Angular Distortion of a weld has been experimentally investigated with focus on the cooling position. A numerical model of welding with a trailing heat sink is constructed through the comparison of measured values of weld penetration, thermal cycles and Angular Distortion with those calculated. On the basis of this model, the effect of welding heat input conditions on the reduction in Angular Distortion is discussed to evaluate the versatility of welding with a trailing heat sink. The results indicate that the choice of an appropriate cooling position behind the welding heat source is essential for the effective reduction in Angular Distortion. The reduction in Angular Distortion by the heat sink at the appropriate cooling position increases with the heat input parameter Qnet/h, where Qnet is the weld heat input and h is the thickness of the plate.
