The Experts below are selected from a list of 309 Experts worldwide ranked by ideXlab platform
He Yang - One of the best experts on this subject based on the ideXlab platform.
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Application Research on Expert System of Incremental In-Plane Bending
Materials Science Forum, 2008Co-Authors: Wen Ting Tang, Chao Li Tang, Lei Huang, He YangAbstract:Incremental in-Plane Bending is a flexible and laborsaving manufacturing technology for short production runs in a variety of sizes and shapes. But the technology parameters are interactive intimately and it is hard to forecast and control the Bending radius accurately. Based on the features of incremental in-Plane Bending and the advantage of expert system dealing with problems, an expert system of incremental in-Plane Bending by designing knowledge base of representation of creation regulation, reasoning system based on rules and search mechanism and explaining system based on prefabricating text has been researched and developed in this paper. The system, making use of ADO technology, Access database and Visual Basic, develops knowledge base, database and reasoning system. Based on client / server model, the system realizes a seamless link between Visual Basic and Matlab by using ActiveX. The system can perform functions of Bending radius forecasting and forming program evaluating and optimizing. It has a friendly interface and it is easy to operate and convenient for maintenance.
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A 3D Rigid-Plastic FEM Simulation on Radius of Incremental In-Plane Bending of Strip Metal
Materials Science Forum, 2008Co-Authors: Wen Ting Tang, Li Jin, Jin Zhang, He YangAbstract:In-Plane Bending is an advanced plastic processing technology which controls the uneven compressing plastic deformation of strip metal harmoniously and forces the strip metal to produce in-Plane Bending and to form an open circle. In-Plane Bending is divided into incremental and continuous process according to the loading manner. While much attention has been paid to the continuous in-Plane Bending techniques and achievements have been made at home and abroad, only limited experimental investigation has so for been done on incremental in-Plane Bending by overseas scholars. In this paper, a 3D finite element simulation based on the rigid-plastic principle is performed for incremental in-Plane Bending of pure aluminum sheet with width of 25 ~ 27.5 mm, thickness of 1.5 ~ 3 mm. Influences of technical parameters such as punch inclined angle αp, punch indentation s, thickness of strip t0, width of strip w0 and strip pitch p on the strip Bending radius Rin are studied. The achievement of this study enriches the uneven deformation theory. It lays a theoretical foundation for generalization and industrialization of incremental in-Plane Bending and offers a new idea to the research and development of the advanced plastic processing technologies.
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A coordination model of the in-Plane Bending of strip metal under unequal compression
Journal of Materials Processing Technology, 2001Co-Authors: He Yang, Xian Feijun, Liu YuliAbstract:Abstract The in-Plane Bending of a strip metal workpiece under unequal compression can be developed into an advanced precision forming process with high quality, high efficiency, low consumption, good flexibility for size changes, and a high forming limit, where the forming is difficult to carry out using any other conventional process. To establish a coordination model of the process for the investigation and understanding of the coordinated development of unequal deformation and its contribution to in-Plane Bending forming is one of the key problems urgently to be solved in the research and development of this advanced in-Plane Bending process. In this paper, on the basis of the rectilinear state of the unequally compressive deformation conducted with two conical rollers and the contribution of the unequal deformation to the in-Plane Bending forming, a coordination coefficient function of the unequal deformation is proposed, and further a coordination model of the in-Plane Bending of strip metal under unequal compression is established. Experimental research is carried out by means of the apparatus made in the authors’ laboratory for performing the in-Plane Bending process under the unequal compression with LF21M and LD2M strip workpieces in order to validate the model. The results obtained show the following: (1) The predictions by using the model are in good agreement with the experimental results. The model as a basic equation describing the process, characterizing the quantitative relationships between the deformation conditions and the forming results, reveals the precision forming law produced by the unequal deformation with its coordination. (2) The greater the unequally compressive deformation, the greater is its contribution to the stable in-Plane Bending forming. The proposed coordination coefficient used for describing this physical phenomenon is found to be practicable and sound. (3) The more notable the unequal compressive state, the higher the stable in-Plane Bending forming limit obtained, and the model provides the basis for the determination and optimization of the in-Plane Bending process. (4) The method described for establishing the coordination model is also of general significance to non-rectilinear states of unequally compressive deformation.
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Instable modes of in-Plane Bending of strip metal under unequal compressing
Journal of Materials Processing Technology, 2000Co-Authors: He Yang, Xian Feijun, Xiao HongshengAbstract:Abstract The in-Plane Bending of a strip metal workpiece under unequal compression can be developed into an advanced precision forming process with high quality, high efficiency, low consumption, and good flexibility for size changing. Moreover, the loading path and stress state of the process make it possible to develop the deformation potentiality of the workpiece to the full and to greatly improve the Bending forming limit of the workpiece, which is difficult to achieve by any other conventional process. The forming limit of the workpiece depends on the modes and the conditions of instability of the process. However, up to now, literature on the instability has been scant. This paper reports research into the mechanism, the modes, and the conditions of instability of the process by a comprehensive analysis based on the minimum energy principle of plastic deformation and by an experiment with LF21M strip workpieces on apparatus made by the authors for performing in-Plane Bending with two conical rollers. The research results show the following: (1) Because the in-Plane Bending process has a specific three-dimensional compressive stress state and the resistance to instability is determined by the geometry parameters and the property values of the workpiece, there are three new modes of instability of the process, different from those of conventional Bending processes. (2) For a given material the original thickness t 0 , original width b 0 , unequal compression width a z , and the smallest thickness of the formed workpiece t 1 , there are the instability parameters of K 1 , K 2 , K 3 , m 1 , and m 2 , and they satisfy the conditions of 0 K 1 K 2 K 3 and 0 m 1 m 2 . It is possible for the workpiece to produce external wrinkling when a z / b 0 ≤ K 1 or t 1 / t 0 ≤ m 1 , the turning when K 1 a z / b 0 ≤ K 2 and m 1 t 1 / t 0 ≤ m 2 , and the internal wrinkling when K 2 a z / b 0 ≤ K 3 and m 1 t 1 / t 0 ≤ m 2 . When a z / b 0 > K 3 and m 1 t 1 / t 0 ≤ m 2 , the workpiece can perform a stable process of in-Plane Bending and greatly improve the Bending forming limit without any mode of instability. The approximate values of K 1 , K 2 , K 3 , m 1 , and m 2 for strip workpieces LF21M alloy (sheet thickness: 1.90 and 1.50 mm) are 0.25, 0.45, 0.60, 0.30, and 0.95, respectively. (3) The greater are the elastic modulus E and the strain-hardening modulus D of the material used, the smaller are the instability values of K 1 , K 2 , K 3 , and m 1 , and the greater is the value of m 2 . The achievements of this research can serve as a significant guide to the determination of the forming limit and the optimal process parameters for the practice of the relevant processes.
Makoto Murata - One of the best experts on this subject based on the ideXlab platform.
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Effect of beating pitch on in-Plane Bending behavior of sheet metal in incremental beat Bending
Journal of Japan Institute of Light Metals, 2006Co-Authors: Yingjun Jin, Takashi Kuboki, Makoto MurataAbstract:Indentation of punch, beating angle and beating pitch are dominant factors for incremental in-Plane Bending process. In this paper, the effects of beating pitch on beating force, Bending radius and strains in the three directions are clarified by finite element analysis and experiment. The results show that the beating pitch has no effect on Bending radius when the actual indentation is same. On the other hand, when the setting indentation is fixed, the beating pitch has an effect on Bending radius due to the elastic deformation of punch and the support part. These forming properties of in-Plane Bending obtained by analysis and experiment had an agreement.
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Influence of strip materials on behavior of incremental in-Plane Bending
Journal of Materials Processing Technology, 2005Co-Authors: Yingjun Jin, Takashi Kuboki, Makoto MurataAbstract:Abstract Incremental in-Plane Bending that has been invented by authors is a new and flexible manufacturing technology for small-lot production of strip with various Bending radii. The strip is bent incrementally by an inclined punch beating. The prototype incremental Bending machine uses the numerical control technology and bends the strip flexibly. The strip material is an important condition for in-Plane Bending. The Bending experiments are carried out and some experimental results such as beating force, Bending radius, strain distribution are experimentally examined. The forming properties of in-Plane Bending are clarified in this study. Moreover, the approximate formulas for calculation the Bending radius are proposed. The Bending radius calculated by the proposed formula agrees with one of the experiments.
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Influence of pitch and cross-sectional ratio of strip of sheet metal on incremental in-Plane Bending
Journal of Materials Processing Technology, 2004Co-Authors: Yingjun Jin, Makoto MurataAbstract:Abstract Incremental in-Plane Bending which has been invented by authors is a new and flexible manufacturing technology for short production runs in a variety of sizes and shapes. The strip of sheet metal is bent incrementally by an inclined punch beating according to the control program. The prototype incremental Bending machine, which has been invented and produced, uses the numerical control technology and bends the strip of sheet metal flexibly. The cross-sectional ratio of width to thickness of sheet metal and the pitch are important for in-Plane Bending conditions. The Bending experiment is carried out and some experimental results such as beating force, Bending radius and strain distribution are experimentally examined. The forming properties of in-Plane Bending are clarified in this study.
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effect of indentation in in Plane Bending of sheet metal by incremental beating
Journal of Japan Institute of Light Metals, 2004Co-Authors: Yingjun Jin, Takashi Kuboki, Makoto MurataAbstract:Incremental in-Plane Bending which has been invented by authors is a new and flexible manufacturing technology for small-lot production of sheet metal with various Bending radii. The sheet metal is bent incrementally by an inclined-punch beating. The prototype incremental Bending machine uses the numerical control technology and bends the sheet metal flexibly. The Bending experiments are carried out and some experimental results such as beating force, Bending radius, strain distribution are experimentally examined. The forming properties of in-Plane Bending are clarified in this study. Moreover, approximate formulas for calculating the Bending radius are proposed base on the Plane strain. The Bending radius calculated by the proposed formula agrees with the one of the experiments.
Yan Peng - One of the best experts on this subject based on the ideXlab platform.
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Basal Plane Bending of Homoepitaxial MPCVD Single-Crystal Diamond.
Materials (Basel Switzerland), 2020Co-Authors: Xiaotong Han, Yan Peng, Peng Duan, Xuejian Xie, Xiwei Wang, Dufu WangAbstract:We report herein high-resolution X-ray diffraction measurements of basal Plane Bending of homoepitaxial single-crystal diamond (SCD). We define SCD (100) as the base Plane. The results revealed that growth parameters such as temperature, growth time, and basal Plane Bending of the substrate all affect the basal Plane Bending of SCD. First, the basal Plane Bending of SCD depends mainly on the substrate and becomes severe with increasing basal Plane Bending of the substrate. The SCD growth experiments show that the basal Plane Bending increases with elevated growth temperature and increased growth time. Finally, to understand the mechanism, we investigated the substrate-surface temperature distribution as a function of basal Plane Bending of SCD fabricated by chemical vapor deposition (CVD). This allowed us to propose a model and understand the origin of basal Plane Bending. The results indicate that an uneven temperature distribution on the substrate surface is the main cause of the base-Plane Bending of CVD diamond.
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Basal Plane Bending of Homoepitaxial MPCVD Single-crystal Diamond
2020Co-Authors: Xiaotong Han, Yan Peng, Peng Duan, Xuejian Xie, Xiwei Wang, Dufu Wang, Hu Xiaobo, Xu XiangangAbstract:We report herein high-resolution x-ray diffraction measurements of basal Plane Bending of homoepitaxial single-crystal diamond (SCD). The results reveal that growth parameters such as temperature, growth time and basal Plane Bending of the substrate affect the basal Plane Bending of SCD. First, the basal Plane Bending of SCD depends mainly on the substrate itself. The basal Plane Bending of SCD becomes more severe with increasing basal Plane Bending of the substrate and this type of basal Plane Bending cannot be recovered. The SCD growth experiments show that the basal Plane Bending increases at high temperature and with increasing growth time. Finally, to understand the mechanism behind basal Plane Bending, we investigate the substrate-surface temperature distribution as a function of basal Plane Bending of SCD fabricated by chemical vapour deposition (CVD). This allows us to propose a Bending model and understand the origin of basal Plane Bending. The results indicate that an uneven temperature distribution on the substrate surface is the main cause of the CVD diamond base-Plane Bending.
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Basal Plane Bending of 4H-SiC single crystals grown by sublimation method with different seed attachment methods
CrystEngComm, 2018Co-Authors: Xianglong Yang, Xiao Bo Hu, Xiu Fang Chen, Xian Gang Xu, Jinying Yu, Xianglai Yang, Yingxin Song, Yan Peng, Ruiqi WangAbstract:Basal Plane Bending of 4H-SiC single crystals grown using the sublimation method on an open or closed backside seed was measured using high-resolution X-ray diffractometry. In order to allow full information to be obtained about the complexity of basal Plane Bending, line scans of the 0004 reflection rocking curves were carried out on the (0001) Si face along the , , , , and directions. The measurement results revealed the seed attachment had a pronounced effect on the basal Plane Bending behaviors. The single crystals grown on a closed backside seed exhibit strong basal Plane Bending which is rotationally symmetric and concave towards the growth direction. However, the single crystals grown on an open backside seed show much weaker basal Plane Bending. The basal Plane Bending inheritance of 4H-SiC single crystals grown by sublimation with two different seed attachment methods was studied. Moreover, the basal Plane Bending characteristics of 4H-SiC crystals grown on an open backside seed with apparent axisymmetric basal Plane Bending were investigated. Molten KOH etching was carried out to correlate the basal Plane Bending with the distribution of structural defects to understand the basal Plane Bending mechanism. Finally, the effect of macroscopic shear stress resulting from the difference in the thermal expansion coefficient between the silicon carbide (SiC) seed and graphite holder and the induced structural defects on the basal Plane Bending of 4H-SiC single crystals was explored.
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Basal Plane Bending of 6H-SiC single crystals observed by synchrotron radiation X-ray topography
Journal of Applied Crystallography, 2009Co-Authors: Lina Ning, Xiu Fang Chen, Yan Peng, Yingmin Wang, Yuqiang Gao, Wanxia Huang, Qingxi YuanAbstract:Basal Plane Bending is a structural defect in SiC single crystals caused mainly by the thermal mismatch between seed and holder, which deteriorates the quality of the wafers and blocks their applications. In this paper, basal Plane Bending was detected by high-resolution X-ray diffractometry (HRXRD) and transmission synchrotron white-beam X-ray topography (SWBXT). HRXRD reveals that the (0001) Si face is a concave sphere and SWBXT shows that the shapes of the Laue spots are different from that of the cross section of the synchrotron radiation beam. On the basis of a spherical curvature model for a (0001) 6H-SiC single crystal, the shapes of the Laue spots were simulated. The results are in good agreement with the experimental observations. Thus, SWBXT is an effective method for detecting basal Plane Bending.
Xian Feijun - One of the best experts on this subject based on the ideXlab platform.
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A coordination model of the in-Plane Bending of strip metal under unequal compression
Journal of Materials Processing Technology, 2001Co-Authors: He Yang, Xian Feijun, Liu YuliAbstract:Abstract The in-Plane Bending of a strip metal workpiece under unequal compression can be developed into an advanced precision forming process with high quality, high efficiency, low consumption, good flexibility for size changes, and a high forming limit, where the forming is difficult to carry out using any other conventional process. To establish a coordination model of the process for the investigation and understanding of the coordinated development of unequal deformation and its contribution to in-Plane Bending forming is one of the key problems urgently to be solved in the research and development of this advanced in-Plane Bending process. In this paper, on the basis of the rectilinear state of the unequally compressive deformation conducted with two conical rollers and the contribution of the unequal deformation to the in-Plane Bending forming, a coordination coefficient function of the unequal deformation is proposed, and further a coordination model of the in-Plane Bending of strip metal under unequal compression is established. Experimental research is carried out by means of the apparatus made in the authors’ laboratory for performing the in-Plane Bending process under the unequal compression with LF21M and LD2M strip workpieces in order to validate the model. The results obtained show the following: (1) The predictions by using the model are in good agreement with the experimental results. The model as a basic equation describing the process, characterizing the quantitative relationships between the deformation conditions and the forming results, reveals the precision forming law produced by the unequal deformation with its coordination. (2) The greater the unequally compressive deformation, the greater is its contribution to the stable in-Plane Bending forming. The proposed coordination coefficient used for describing this physical phenomenon is found to be practicable and sound. (3) The more notable the unequal compressive state, the higher the stable in-Plane Bending forming limit obtained, and the model provides the basis for the determination and optimization of the in-Plane Bending process. (4) The method described for establishing the coordination model is also of general significance to non-rectilinear states of unequally compressive deformation.
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Instable modes of in-Plane Bending of strip metal under unequal compressing
Journal of Materials Processing Technology, 2000Co-Authors: He Yang, Xian Feijun, Xiao HongshengAbstract:Abstract The in-Plane Bending of a strip metal workpiece under unequal compression can be developed into an advanced precision forming process with high quality, high efficiency, low consumption, and good flexibility for size changing. Moreover, the loading path and stress state of the process make it possible to develop the deformation potentiality of the workpiece to the full and to greatly improve the Bending forming limit of the workpiece, which is difficult to achieve by any other conventional process. The forming limit of the workpiece depends on the modes and the conditions of instability of the process. However, up to now, literature on the instability has been scant. This paper reports research into the mechanism, the modes, and the conditions of instability of the process by a comprehensive analysis based on the minimum energy principle of plastic deformation and by an experiment with LF21M strip workpieces on apparatus made by the authors for performing in-Plane Bending with two conical rollers. The research results show the following: (1) Because the in-Plane Bending process has a specific three-dimensional compressive stress state and the resistance to instability is determined by the geometry parameters and the property values of the workpiece, there are three new modes of instability of the process, different from those of conventional Bending processes. (2) For a given material the original thickness t 0 , original width b 0 , unequal compression width a z , and the smallest thickness of the formed workpiece t 1 , there are the instability parameters of K 1 , K 2 , K 3 , m 1 , and m 2 , and they satisfy the conditions of 0 K 1 K 2 K 3 and 0 m 1 m 2 . It is possible for the workpiece to produce external wrinkling when a z / b 0 ≤ K 1 or t 1 / t 0 ≤ m 1 , the turning when K 1 a z / b 0 ≤ K 2 and m 1 t 1 / t 0 ≤ m 2 , and the internal wrinkling when K 2 a z / b 0 ≤ K 3 and m 1 t 1 / t 0 ≤ m 2 . When a z / b 0 > K 3 and m 1 t 1 / t 0 ≤ m 2 , the workpiece can perform a stable process of in-Plane Bending and greatly improve the Bending forming limit without any mode of instability. The approximate values of K 1 , K 2 , K 3 , m 1 , and m 2 for strip workpieces LF21M alloy (sheet thickness: 1.90 and 1.50 mm) are 0.25, 0.45, 0.60, 0.30, and 0.95, respectively. (3) The greater are the elastic modulus E and the strain-hardening modulus D of the material used, the smaller are the instability values of K 1 , K 2 , K 3 , and m 1 , and the greater is the value of m 2 . The achievements of this research can serve as a significant guide to the determination of the forming limit and the optimal process parameters for the practice of the relevant processes.
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Research Advance Ments of In-Plane Bending of Strip Metal under Unequal Compressing
2000Co-Authors: Xian FeijunAbstract:In-Plane Bending of strip metal under unequal compressing is an advanced forming process.The authors presented different kinds of In-Plane Bending types, process characteristics,research advancements and the perspectives of their applications at home and abroad. It is emphasized that the process execnted with two conical rollers has the marked advantages of good flexibility, low energy consumption, high precision and high material utilization, and can improve the forming limit greatly. In order to promote the research and development of the process,somekey technologies,such as the coordinate mechanism of unequal deformation,the influence of process parameters and the forming limits,will be stuclied continnously and systematically.
Yingjun Jin - One of the best experts on this subject based on the ideXlab platform.
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Effect of beating pitch on in-Plane Bending behavior of sheet metal in incremental beat Bending
Journal of Japan Institute of Light Metals, 2006Co-Authors: Yingjun Jin, Takashi Kuboki, Makoto MurataAbstract:Indentation of punch, beating angle and beating pitch are dominant factors for incremental in-Plane Bending process. In this paper, the effects of beating pitch on beating force, Bending radius and strains in the three directions are clarified by finite element analysis and experiment. The results show that the beating pitch has no effect on Bending radius when the actual indentation is same. On the other hand, when the setting indentation is fixed, the beating pitch has an effect on Bending radius due to the elastic deformation of punch and the support part. These forming properties of in-Plane Bending obtained by analysis and experiment had an agreement.
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Influence of strip materials on behavior of incremental in-Plane Bending
Journal of Materials Processing Technology, 2005Co-Authors: Yingjun Jin, Takashi Kuboki, Makoto MurataAbstract:Abstract Incremental in-Plane Bending that has been invented by authors is a new and flexible manufacturing technology for small-lot production of strip with various Bending radii. The strip is bent incrementally by an inclined punch beating. The prototype incremental Bending machine uses the numerical control technology and bends the strip flexibly. The strip material is an important condition for in-Plane Bending. The Bending experiments are carried out and some experimental results such as beating force, Bending radius, strain distribution are experimentally examined. The forming properties of in-Plane Bending are clarified in this study. Moreover, the approximate formulas for calculation the Bending radius are proposed. The Bending radius calculated by the proposed formula agrees with one of the experiments.
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Influence of pitch and cross-sectional ratio of strip of sheet metal on incremental in-Plane Bending
Journal of Materials Processing Technology, 2004Co-Authors: Yingjun Jin, Makoto MurataAbstract:Abstract Incremental in-Plane Bending which has been invented by authors is a new and flexible manufacturing technology for short production runs in a variety of sizes and shapes. The strip of sheet metal is bent incrementally by an inclined punch beating according to the control program. The prototype incremental Bending machine, which has been invented and produced, uses the numerical control technology and bends the strip of sheet metal flexibly. The cross-sectional ratio of width to thickness of sheet metal and the pitch are important for in-Plane Bending conditions. The Bending experiment is carried out and some experimental results such as beating force, Bending radius and strain distribution are experimentally examined. The forming properties of in-Plane Bending are clarified in this study.
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effect of indentation in in Plane Bending of sheet metal by incremental beating
Journal of Japan Institute of Light Metals, 2004Co-Authors: Yingjun Jin, Takashi Kuboki, Makoto MurataAbstract:Incremental in-Plane Bending which has been invented by authors is a new and flexible manufacturing technology for small-lot production of sheet metal with various Bending radii. The sheet metal is bent incrementally by an inclined-punch beating. The prototype incremental Bending machine uses the numerical control technology and bends the sheet metal flexibly. The Bending experiments are carried out and some experimental results such as beating force, Bending radius, strain distribution are experimentally examined. The forming properties of in-Plane Bending are clarified in this study. Moreover, approximate formulas for calculating the Bending radius are proposed base on the Plane strain. The Bending radius calculated by the proposed formula agrees with the one of the experiments.