The Experts below are selected from a list of 78 Experts worldwide ranked by ideXlab platform
Ying-jun Li - One of the best experts on this subject based on the ideXlab platform.
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dynamic characteristics and optimization research on pvdf piezoelectric film force sensor for steel ball Cold Heading machine
Isa Transactions, 2019Co-Authors: Ying-jun Li, Guicong Wang, Xiangyu WangAbstract:Abstract According to Cold Heading process with overloaded craft, high-impact dynamic real-time measurement requirements, this paper presents researches on dynamic characteristics and optimization of PVDF piezoelectric film force sensor for steel ball Cold Heading forming quality monitoring, through the combination method of mechanism analysis, mathematical modeling, numerical simulation and experimental validation. The motivation and strategic objectives are to breakthrough dynamic time-varying impacting load measuring fundamental technologies in steel ball forging process. The structure of piezoelectric film force sensor is proposed. The theoretical calculation formula of natural frequency is deduced and calculated by using MATLAB software. The mechanical performance analysis on dynamic model and structural optimization simulation by FEM is carried out. In order to study the validity of the proposed method, a prototype of the sensor is fabricated. The static and dynamic calibration devices are designed to realize calibration experiments on the fabricated PVDF piezoelectric film force sensor. The differences among experimental value, simulation value and the theoretical value are given. The nonlinear error of the fabricated sensor is 0.197%. The sensor’s first order natural frequency value is 5238 Hz. It is proved that the PVDF piezoelectric film force sensor has superior dynamic performance and high accuracy for measuring deformation in steel ball. The paper will provide important scientific basis and technical foundation to achieve superior performance steel ball.
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Optimization on PVDF Film Force Sensor for Steel Ball Forging Fault Diagnosis
2018 IEEE International Conference of Intelligent Robotic and Control Engineering (IRCE), 2018Co-Authors: Ying-jun Li, Guicong Wang, Xiangyu WangAbstract:Bearing capacity and sensitivity are two important indicators of force sensor measurement performance. In this paper, the parameters optimization and performance analysis of the piezoelectric film force sensor for steel ball Cold Heading machine are carried out for the piezoelectric film force sensor for detecting Cold ball force of steel ball. In order to avoid local stress concentration, a modified scheme of the structure of the piezoelectric film force sensor is proposed. A finite element model of the sensor was established, and then the main parameters affecting the bearing capacity and sensitivity of the sensor were simulated and optimized. The size of the sensor stress concentration area was analyzed. Finally, the optimized size parameters of the piezoelectric film force sensor were obtained, which improved the sensor sensitivity and its load capacity.
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Research on on-line monitoring technology for steel ball's forming process based on load signal analysis method
Mechanical Systems and Signal Processing, 2013Co-Authors: Ying-jun Li, Cheng-liang Zhang, Xiu-hua Men, Chang Sheng Ai, Qi ZhangAbstract:This paper presents a novel on-line monitoring technology to obtain forming quality in steel ball's forming process based on load signal analysis method, in order to reveal the bottom die's load characteristic in initial Cold Heading forging process of steel balls. A mechanical model of the Cold header producing process is established and analyzed by using finite element method. The maximum Cold Heading force is calculated. The results prove that the monitoring on the Cold Heading process with upsetting force is reasonable and feasible. The forming defects are inflected on the three feature points of the bottom die signals, which are the initial point, infection point, and peak point. A novel PVDF piezoelectric force sensor which is simple on construction and convenient on installation is designed. The sensitivity of the PVDF force sensor is calculated. The characteristics of PVDF force sensor are analyzed by FEM. The PVDF piezoelectric force sensor is fabricated to acquire the actual load signals in the Cold Heading process, and calibrated by a special device. The measuring system of on-line monitoring is built. The characteristics of the actual signals recognized by learning and identification algorithm are in consistence with simulation results. Identification of actual signals shows that the timing difference values of all feature points for qualified products are not exceed ±6ms, and amplitude difference values are less than ±3%. The calibration and application experiments show that PVDF force sensor has good static and dynamic performances, and is competent at dynamic measuring on upsetting force. It greatly improves automatic level and machining precision. Equipment capacity factor with damages identification method depends on grade of steel has been improved to 90%.
Xiangyu Wang - One of the best experts on this subject based on the ideXlab platform.
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dynamic characteristics and optimization research on pvdf piezoelectric film force sensor for steel ball Cold Heading machine
Isa Transactions, 2019Co-Authors: Ying-jun Li, Guicong Wang, Xiangyu WangAbstract:Abstract According to Cold Heading process with overloaded craft, high-impact dynamic real-time measurement requirements, this paper presents researches on dynamic characteristics and optimization of PVDF piezoelectric film force sensor for steel ball Cold Heading forming quality monitoring, through the combination method of mechanism analysis, mathematical modeling, numerical simulation and experimental validation. The motivation and strategic objectives are to breakthrough dynamic time-varying impacting load measuring fundamental technologies in steel ball forging process. The structure of piezoelectric film force sensor is proposed. The theoretical calculation formula of natural frequency is deduced and calculated by using MATLAB software. The mechanical performance analysis on dynamic model and structural optimization simulation by FEM is carried out. In order to study the validity of the proposed method, a prototype of the sensor is fabricated. The static and dynamic calibration devices are designed to realize calibration experiments on the fabricated PVDF piezoelectric film force sensor. The differences among experimental value, simulation value and the theoretical value are given. The nonlinear error of the fabricated sensor is 0.197%. The sensor’s first order natural frequency value is 5238 Hz. It is proved that the PVDF piezoelectric film force sensor has superior dynamic performance and high accuracy for measuring deformation in steel ball. The paper will provide important scientific basis and technical foundation to achieve superior performance steel ball.
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Optimization on PVDF Film Force Sensor for Steel Ball Forging Fault Diagnosis
2018 IEEE International Conference of Intelligent Robotic and Control Engineering (IRCE), 2018Co-Authors: Ying-jun Li, Guicong Wang, Xiangyu WangAbstract:Bearing capacity and sensitivity are two important indicators of force sensor measurement performance. In this paper, the parameters optimization and performance analysis of the piezoelectric film force sensor for steel ball Cold Heading machine are carried out for the piezoelectric film force sensor for detecting Cold ball force of steel ball. In order to avoid local stress concentration, a modified scheme of the structure of the piezoelectric film force sensor is proposed. A finite element model of the sensor was established, and then the main parameters affecting the bearing capacity and sensitivity of the sensor were simulated and optimized. The size of the sensor stress concentration area was analyzed. Finally, the optimized size parameters of the piezoelectric film force sensor were obtained, which improved the sensor sensitivity and its load capacity.
James A Nemes - One of the best experts on this subject based on the ideXlab platform.
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experimental and finite element simulation study of the adiabatic shear band phenomenon in Cold Heading process
Journal of Materials Processing Technology, 2012Co-Authors: A Sabih, James A NemesAbstract:Abstract This paper presents the outcomes of a comprehensive experimental, metallurgical and finite element (FE) simulation study to characterize the development of adiabatic shear band (ASB) phenomenon in steel Cold Heading (CH) process. The main objective of this work is to investigate the complex interplay of different process and material parameters on the ASB development stages inside the Cold headed parts. In this work, the drop weight compression test (DWCT) was selected to simulate the CH process impact loads on specimens machined from 1038 steel and 1018 steel. Series of DWCTs were performed under different impact loading conditions. The goal of these tests is to achieve different deformation levels and introduce ASBs at different stages. To reach a full understanding of this complex phenomenon, the FE simulation analysis was used to support the metallurgical examination of the DWCT specimens. The FE analysis provided important details about the changes of different material and process parameters at the critical zones inside the ASBs. This study confirmed that the ASB is mainly a thermo-mechanically controlled phenomenon. The ASBs develop in three stages: homogeneous plastic strain, inhomogeneous plastic strain, and strain localization. The ASB development stage depends mainly on the status of the competition between the work hardening and the thermal and geometrical softening mechanisms inside the bands. The domination of the softening mechanisms at advanced levels of deformation triggers a self-catalytic strain localization and material strength degradation process that leads to failure inside the band. In general, the metallurgical and finite element analysis investigation revealed that under impact loads, three ASBs can develop simultaneously inside the Cold headed parts; lower, upper and central ASBs. As the deformation continues; the development of the lower and upper bands slows down and contributes in the rapid development of the adjacent central ASB. This study confirmed that the ASB has a canonical structure which leads to an ASB that can experience different development stages along the same band simultaneously. This study proved that the shape and the type of ASBs in Cold headed parts depend highly on material's properties. The metallurgical and finite element analysis revealed that the higher the strength of the tested steel, the easier to form a narrow ASB that reaches the localization stage at low deformation levels. In contrast, ductile steels experience wider ASBs when subjected to the same deformation levels. These bands require higher levels of deformation to reach the localization stage in comparison to higher strength steels.
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internal ductile failure mechanisms in steel Cold Heading process
Journal of Materials Processing Technology, 2009Co-Authors: A Sabih, James A NemesAbstract:Abstract The occurrence of internal ductile failure in Cold-headed products presents a major obstacle in the fast expanding Cold Heading (CH) industry. This internal failure may lead to catastrophic brittle fracture under tensile loads despite the ductile nature of the material. Comprehensive testing and investigation methodologies were used to this work to reveal the complicated interplay of process and material parameters contributing in the initiation and propagation of internal ductile failure in six CH quality AISI steel grades. The metallurgical and microscopic investigations showed that internal ductile failure occurs progressively by void nucleation and growth mechanisms with increasing plastic strain inside the highly localized adiabatic shear bands (ASBs). The void nucleation occurs by decohesion at second-phase particles, inclusion–matrix interfaces, grain boundaries and by particle or inclusion cracking. Therefore, the number and morphology of any inclusions and second-phase particles are key factors in material formability. The metallurgical investigations showed that under compressive loading conditions, the nature of the metal flow pattern promotes different rates of material flow around the inclusions and stringers which supports decohesion and void nucleation since the early stages of deformation. At advanced stages of deformation, the metal flow pattern contributes to the ASB localization in supporting void growth and coalescence along the band leading to narrow void sheets. All tested materials in this work experienced ductile failure by void nucleation and coalescence, forming cracks along the ASBs. The ductile failure of each material was the result of the contribution of all the mechanisms of void nucleation at the inclusion–matrix interface, second phase–matrix interface and at the grain boundaries. However, the level of contribution of each mechanism in the final ductile failure varied depending on material properties and their microstructure.
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a workability criterion for the transformed adiabatic shear band phenomena during Cold Heading of 1038 steel
Journal of Failure Analysis and Prevention, 2006Co-Authors: A Sabih, A.m. Elwazri, James A NemesAbstract:A criterion for predicting the workability limits for internal britde failure was developed for Cold Heading of 1038 steel. The criterion considers internal defects caused by microstructural changes generated by adiabatic shear. This transformation is termed the transformed adiabatic shear band (TASB) phenomena. The defect that develops is the formation ofbritde martensite as a result ofthe temperature rise and fall inside the adiabatic shear band (ASB). In this work, the material is considered to have a TASB defect when the temperature inside the ASB exceeds the phase transformation temperature (AC3). The empirical formulas provided by Andrews[1] were used to determine transformation temperatures. Microhardness testing and etching with 2% Nital and Le Pera etchants were performed on the sectioned specimens to locate and study the TASB. In order to simulate the Cold Heading process, a drop weight compression test was used and modeled with finite-element analysis (implemented within ABAQUS/Explicit).
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the workability criteria for adiabatic shear band phenomena in the dual phase steel Cold Heading process
MATERIALS PROCESSING AND DESIGN: Modeling Simulation and Applications - NUMIFORM 2004 - Proceedings of the 8th International Conference on Numerical M, 2004Co-Authors: A Sabih, James A NemesAbstract:Criteria for predicting the workability limits for internal failure in dual‐phase steel Cold‐headed parts are presented in this paper. This workability criterion is divided into two sub‐criteria to predict the two internal defect types triggered by the adiabatic shear band (ASB) phenomena. These defects are internal voids and cracks (deformed ASB) and/or development of brittle martensite inside the band as a result of phase transformation due to the temperature rise inside the ASB (transformed ASB). The presence of one or both failure types may result in splitting of the fastener’s heads.
A Sabih - One of the best experts on this subject based on the ideXlab platform.
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experimental and finite element simulation study of the adiabatic shear band phenomenon in Cold Heading process
Journal of Materials Processing Technology, 2012Co-Authors: A Sabih, James A NemesAbstract:Abstract This paper presents the outcomes of a comprehensive experimental, metallurgical and finite element (FE) simulation study to characterize the development of adiabatic shear band (ASB) phenomenon in steel Cold Heading (CH) process. The main objective of this work is to investigate the complex interplay of different process and material parameters on the ASB development stages inside the Cold headed parts. In this work, the drop weight compression test (DWCT) was selected to simulate the CH process impact loads on specimens machined from 1038 steel and 1018 steel. Series of DWCTs were performed under different impact loading conditions. The goal of these tests is to achieve different deformation levels and introduce ASBs at different stages. To reach a full understanding of this complex phenomenon, the FE simulation analysis was used to support the metallurgical examination of the DWCT specimens. The FE analysis provided important details about the changes of different material and process parameters at the critical zones inside the ASBs. This study confirmed that the ASB is mainly a thermo-mechanically controlled phenomenon. The ASBs develop in three stages: homogeneous plastic strain, inhomogeneous plastic strain, and strain localization. The ASB development stage depends mainly on the status of the competition between the work hardening and the thermal and geometrical softening mechanisms inside the bands. The domination of the softening mechanisms at advanced levels of deformation triggers a self-catalytic strain localization and material strength degradation process that leads to failure inside the band. In general, the metallurgical and finite element analysis investigation revealed that under impact loads, three ASBs can develop simultaneously inside the Cold headed parts; lower, upper and central ASBs. As the deformation continues; the development of the lower and upper bands slows down and contributes in the rapid development of the adjacent central ASB. This study confirmed that the ASB has a canonical structure which leads to an ASB that can experience different development stages along the same band simultaneously. This study proved that the shape and the type of ASBs in Cold headed parts depend highly on material's properties. The metallurgical and finite element analysis revealed that the higher the strength of the tested steel, the easier to form a narrow ASB that reaches the localization stage at low deformation levels. In contrast, ductile steels experience wider ASBs when subjected to the same deformation levels. These bands require higher levels of deformation to reach the localization stage in comparison to higher strength steels.
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internal ductile failure mechanisms in steel Cold Heading process
Journal of Materials Processing Technology, 2009Co-Authors: A Sabih, James A NemesAbstract:Abstract The occurrence of internal ductile failure in Cold-headed products presents a major obstacle in the fast expanding Cold Heading (CH) industry. This internal failure may lead to catastrophic brittle fracture under tensile loads despite the ductile nature of the material. Comprehensive testing and investigation methodologies were used to this work to reveal the complicated interplay of process and material parameters contributing in the initiation and propagation of internal ductile failure in six CH quality AISI steel grades. The metallurgical and microscopic investigations showed that internal ductile failure occurs progressively by void nucleation and growth mechanisms with increasing plastic strain inside the highly localized adiabatic shear bands (ASBs). The void nucleation occurs by decohesion at second-phase particles, inclusion–matrix interfaces, grain boundaries and by particle or inclusion cracking. Therefore, the number and morphology of any inclusions and second-phase particles are key factors in material formability. The metallurgical investigations showed that under compressive loading conditions, the nature of the metal flow pattern promotes different rates of material flow around the inclusions and stringers which supports decohesion and void nucleation since the early stages of deformation. At advanced stages of deformation, the metal flow pattern contributes to the ASB localization in supporting void growth and coalescence along the band leading to narrow void sheets. All tested materials in this work experienced ductile failure by void nucleation and coalescence, forming cracks along the ASBs. The ductile failure of each material was the result of the contribution of all the mechanisms of void nucleation at the inclusion–matrix interface, second phase–matrix interface and at the grain boundaries. However, the level of contribution of each mechanism in the final ductile failure varied depending on material properties and their microstructure.
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a workability criterion for the transformed adiabatic shear band phenomena during Cold Heading of 1038 steel
Journal of Failure Analysis and Prevention, 2006Co-Authors: A Sabih, A.m. Elwazri, James A NemesAbstract:A criterion for predicting the workability limits for internal britde failure was developed for Cold Heading of 1038 steel. The criterion considers internal defects caused by microstructural changes generated by adiabatic shear. This transformation is termed the transformed adiabatic shear band (TASB) phenomena. The defect that develops is the formation ofbritde martensite as a result ofthe temperature rise and fall inside the adiabatic shear band (ASB). In this work, the material is considered to have a TASB defect when the temperature inside the ASB exceeds the phase transformation temperature (AC3). The empirical formulas provided by Andrews[1] were used to determine transformation temperatures. Microhardness testing and etching with 2% Nital and Le Pera etchants were performed on the sectioned specimens to locate and study the TASB. In order to simulate the Cold Heading process, a drop weight compression test was used and modeled with finite-element analysis (implemented within ABAQUS/Explicit).
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the workability criteria for adiabatic shear band phenomena in the dual phase steel Cold Heading process
MATERIALS PROCESSING AND DESIGN: Modeling Simulation and Applications - NUMIFORM 2004 - Proceedings of the 8th International Conference on Numerical M, 2004Co-Authors: A Sabih, James A NemesAbstract:Criteria for predicting the workability limits for internal failure in dual‐phase steel Cold‐headed parts are presented in this paper. This workability criterion is divided into two sub‐criteria to predict the two internal defect types triggered by the adiabatic shear band (ASB) phenomena. These defects are internal voids and cracks (deformed ASB) and/or development of brittle martensite inside the band as a result of phase transformation due to the temperature rise inside the ASB (transformed ASB). The presence of one or both failure types may result in splitting of the fastener’s heads.
Guicong Wang - One of the best experts on this subject based on the ideXlab platform.
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dynamic characteristics and optimization research on pvdf piezoelectric film force sensor for steel ball Cold Heading machine
Isa Transactions, 2019Co-Authors: Ying-jun Li, Guicong Wang, Xiangyu WangAbstract:Abstract According to Cold Heading process with overloaded craft, high-impact dynamic real-time measurement requirements, this paper presents researches on dynamic characteristics and optimization of PVDF piezoelectric film force sensor for steel ball Cold Heading forming quality monitoring, through the combination method of mechanism analysis, mathematical modeling, numerical simulation and experimental validation. The motivation and strategic objectives are to breakthrough dynamic time-varying impacting load measuring fundamental technologies in steel ball forging process. The structure of piezoelectric film force sensor is proposed. The theoretical calculation formula of natural frequency is deduced and calculated by using MATLAB software. The mechanical performance analysis on dynamic model and structural optimization simulation by FEM is carried out. In order to study the validity of the proposed method, a prototype of the sensor is fabricated. The static and dynamic calibration devices are designed to realize calibration experiments on the fabricated PVDF piezoelectric film force sensor. The differences among experimental value, simulation value and the theoretical value are given. The nonlinear error of the fabricated sensor is 0.197%. The sensor’s first order natural frequency value is 5238 Hz. It is proved that the PVDF piezoelectric film force sensor has superior dynamic performance and high accuracy for measuring deformation in steel ball. The paper will provide important scientific basis and technical foundation to achieve superior performance steel ball.
-
Optimization on PVDF Film Force Sensor for Steel Ball Forging Fault Diagnosis
2018 IEEE International Conference of Intelligent Robotic and Control Engineering (IRCE), 2018Co-Authors: Ying-jun Li, Guicong Wang, Xiangyu WangAbstract:Bearing capacity and sensitivity are two important indicators of force sensor measurement performance. In this paper, the parameters optimization and performance analysis of the piezoelectric film force sensor for steel ball Cold Heading machine are carried out for the piezoelectric film force sensor for detecting Cold ball force of steel ball. In order to avoid local stress concentration, a modified scheme of the structure of the piezoelectric film force sensor is proposed. A finite element model of the sensor was established, and then the main parameters affecting the bearing capacity and sensitivity of the sensor were simulated and optimized. The size of the sensor stress concentration area was analyzed. Finally, the optimized size parameters of the piezoelectric film force sensor were obtained, which improved the sensor sensitivity and its load capacity.