The Experts below are selected from a list of 219 Experts worldwide ranked by ideXlab platform
Seungbok Choi - One of the best experts on this subject based on the ideXlab platform.
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vibration control of an hdd disk Spindle System using piezoelectric bimorph shunt damping ii optimal design and shunt damping implementation
Smart Materials and Structures, 2007Co-Authors: Seungbok ChoiAbstract:This paper presents the experimental implementation of piezoelectric shunt damping for an HDD disk-Spindle System. Prior to evaluating the shunt damping performance of the drive, the piezoelectric bimorph designed in part I is optimally redesigned so as to satisfy desirable shunt damping performance. The electrical admittance of the bimorph is derived from the piezoelectric constitutive equation and stress–strain relationship. Subsequently, in order to maximize the electrical admittance two electrodes of the bimorph are formed on an annular piezoelectric disk by considering the target vibration mode. The sensitivity analysis method is then employed to determine the optimal design parameters. After manufacturing the piezoelectric bimorph with optimally obtained design parameters, the vibration control performance of the proposed shunt damping for the HDD disk-Spindle System is empirically evaluated in the frequency domain by changing the impact and measuring points.
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vibration control of an hdd disk Spindle System utilizing piezoelectric bimorph shunt damping i dynamic analysis and modeling of the shunted drive
Smart Materials and Structures, 2007Co-Authors: Seungbok ChoiAbstract:This work proposes a new piezoelectric shunt damping methodology to control the vibration of a computer hard disk drive (HDD) disk-Spindle System. The first part of this work (part I) deals with dynamic modeling of the piezoelectric shunted drive, while the second part of this work (part II) covers experimental implementation of the proposed shunt circuits. In the modeling, a target vibration mode which significantly restricts the recording density increment of the drive is determined by analyzing the dynamic characteristics of the conventional drive. This is achieved by undertaking both modal testing and finite element (FE) analysis. In order to effectively suppress the unwanted vibration of the target mode, a piezoelectric bimorph is then designed and integrated to the drive by considering the mode shapes of the target vibration mode. The mechanical impedance of the shunted bimorph is derived from lamination theory and piezoelectric constitutive equations. In this derivation, the electromechanical coupling coefficient of the shunted drive is analytically incorporated with the mechanical impedance. Using the coupling coefficient, the shunt damping performance for the target vibration mode is predicted and evaluated by presenting the displacement transmissibility.
Kazuo Yamazaki - One of the best experts on this subject based on the ideXlab platform.
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Development of a high torque-high power Spindle System equipped with a synchronous motor for high performance cutting
CIRP Annals - Manufacturing Technology, 2011Co-Authors: Masakazu Soshi, Shunzhou Yu, Shinji Ishii, Kazuo YamazakiAbstract:In order to develop highly stable machining processes in heavy duty milling applications, a study on the development of a high torque-high power Spindle System has been conducted. The study includes the design of a new permanent magnet synchronous motor, drive System and Spindle System with the designed motor, prototype of the Spindle System with the designed motor and experimental evaluation of the entire System by conducting heavy duty milling of a titanium alloy. The results of the experiments show that the Spindle has a high rotational rigidity under heavy duty intermittent cutting processes. © 2011 CIRP.
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a comparative study on the Spindle System equipped with synchronous and induction servo motors for heavy duty milling with highly stable torque control
Cirp Annals-manufacturing Technology, 2010Co-Authors: Z Wang, Masakazu Soshi, Kazuo YamazakiAbstract:In order to create a higher torque Spindle System for productive milling operations, rotational speed stability against the torque disturbance has been studied with respect to the Spindle mechanical design parameters, actuator types and Spindle control algorithms. The study showed a remarkable difference in the Spindle rotational speed stability against torque disturbance between a Spindle System equipped with an induction servo motor and a permanent magnet synchronous servo motor. The results of this study have been obtained by theoretical analysis, numerical simulation and physical experiments, and the experimental study showed that the hybrid actuation Spindle achieves longer tool life.
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A study on the development of a multi-purpose Spindle System for quality productive machining
CIRP Annals - Manufacturing Technology, 2009Co-Authors: Masakazu Soshi, Hideyuki Ishiguro, Kazuo YamazakiAbstract:A compact multi-purpose Spindle for multi-tasking machine tools has been developed such that it can provide high power and torque for lower speed ranges while it rotates at high speeds for light duty machining. The innovative design based on the dual direct drive concept has been adopted such that the size of the Spindle can stay the same as a conventional Spindle of its class. For optimizing the design process, a method based on the complete virtual approach using 3D solid models has been studied and developed. Machining performance has been verified through a physical prototype. © 2009 CIRP.
Liang Zhao - One of the best experts on this subject based on the ideXlab platform.
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thermal error compensation based on genetic algorithm and artificial neural network of the shaft in the high speed Spindle System
Proceedings of the Institution of Mechanical Engineers Part B: Journal of Engineering Manufacture, 2017Co-Authors: Liang Zhao, Hu Shi, Xuesong Mei, Ju YangAbstract:To improve the accuracy, generality and convergence of thermal error compensation model based on traditional neural networks, a genetic algorithm was proposed to optimize the number of the nodes in the hidden layer, the weights and the thresholds of the traditional neural network by considering the shortcomings of the traditional neural networks which converged slowly and was easy to fall into local minima. Subsequently, the grey cluster grouping and statistical correlation analysis were proposed to group temperature variables and select thermal sensitive points. Then, the thermal error models of the high-speed Spindle System were proposed based on the back propagation and genetic algorithm–back propagation neural networks with practical thermal error sample data. Moreover, thermal error compensation equations of three directions and compensation strategy were presented, considering thermal elongation and radial tilt angles. Finally, the real-time thermal error compensation was implemented on the jig bore...
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thermal error compensation of high speed Spindle System based on a modified bp neural network
The International Journal of Advanced Manufacturing Technology, 2017Co-Authors: Liang Zhao, Jun YangAbstract:The accuracy, convergence performance, and robustness of the thermal error model based on traditional artificial neural networks (ANNs) are poor because the model is sensitive to the training data. To improve these performances, the genetic algorithm (GA) and particle swarm optimization (PSO) were used to optimize the parameters of ANNs with back propagation (BP) algorithm, such as the number of neurons in the hidden layer, initial weights, and thresholds. Moreover, the fuzzy cluster grouping and correlation analysis were combined to group and optimize the typical temperature variables to guarantee the robustness of the thermal error models based on BP, GA-BP, and PSO-BP neural networks. Then, thermal error compensation experiments were conducted on the Spindle System of a precision jig borer, and the machining accuracy was increased from 67 to 78 % for the GA-BP model and 89 % for the PSO-BP model, respectively. To validate the effectiveness of the thermal error measurement, modeling, and compensation methods, the test samples were machined and the surface quality of the machined parts was measured. By measuring the dimension error and the surface quality of the machined parts, the results showed that the machining error can be reduced and that the surface quality can be improved by the thermal error compensation. Moreover, the accuracy, convergence performance, and robustness of the thermal error model based on the traditional BP neural network can be improved greatly by GA and PSO.
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Experimental and simulation study on the thermal characteristics of the high-speed Spindle System
Proceedings of the Institution of Mechanical Engineers Part C: Journal of Mechanical Engineering Science, 2016Co-Authors: Chi Ma, Liang Zhao, Jun YangAbstract:High-speed Spindles often suffer from degeneration in its machining accuracy caused by the uneven distribution of temperature field. In order to improve the machining accuracy of high-speed Spindle...
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thermal characteristics analysis and experimental study on the high speed Spindle System
The International Journal of Advanced Manufacturing Technology, 2015Co-Authors: Jun Yang, Liang ZhaoAbstract:In order to avoid the sudden failure of high-speed Spindles in the actual machining process caused by an excessive temperature rise at the design stage, a three-dimensional (3D) finite element analysis (FEA) model was proposed to conduct transient thermal-structure interactive analysis of a high-speed Spindle. The FEA model considered thermal contact resistance (TCR) at solid joints and bearing stiffness to improve the accuracy of traditional thermal models which ignored TCR. However, TCRs at solid joints and bearing stiffness were often ignored in traditional thermal models of high-speed Spindles. This caused inaccuracies in traditional thermal models. The heat generation of the built-in motor was calculated based on the efficiency analysis method proposed by Bossmanns and Tu [1]. Based on the quasi-static mechanics analysis of rolling bearing, the heat generation and stiffness of bearings were calculated by applying the Newton-Raphson algorithm to improve the convergence. The Weierstrass-Mandelbrot (W-M) function, a function of fractal parameters, was used to characterize the rough surface morphology of bearing rings. The fractal parameters were identified by the structure function method and the measurement data of bearing ring’s surface morphology, and a contact mechanics model was developed to calculate the contact parameters used in the model of TCR. Then, a new predictive model for TCR was proposed based on M-T model. The above boundary conditions were applied to the FEA model, and thermal equilibrium experiments were conducted to validate the effectiveness of the model. The results showed that the FEA model was much more accurate than the traditional model which ignored TCRs at solid joints and bearing stiffness.
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Simulation and experimental study on the thermally induced deformations of high-speed Spindle System
Applied Thermal Engineering, 2015Co-Authors: Chi Ma, Xuesong Mei, Jun Yang, Liang Zhao, Hu ShiAbstract:Abstract In order to avoid the degeneration of high-speed Spindle's machining accuracy in actual machining caused by the uneven distribution of temperature field at the design stage, a three-dimensional (3D) finite element analysis (FEA) model, which considered the combined influence of thermal contact resistance (TCR) and bearing stiffness on the accuracy of simulation results, was proposed to conduct transient thermal-structure interactive analysis of motorized Spindles. And the method to calculate the boundary conditions used in the FEM model were discussed in detail, such as the heat loads, convective heat transfer, TCR and bearing stiffness. Based on the quasi-static mechanics analysis of rolling bearing, the transfer relationships among multiple variables in the equilibrium equation set of bearings were analyzed. Newton-Raphson algorithm, which regarded the contact angle as the iteration variable, was proposed to calculate the heat power and stiffness of bearings and improve the convergence of the algorithm, and the termination criteria of contact angle's searching trial calculation was proposed to improve the accuracy of the algorithm. The Weierstrass-Mandelbrot (W-M) function in fractal geometry was used to characterize the rough surface morphology of bearing rings. The fractal parameters were identified by the power spectrum method, and a contact deformation model of asperities was developed to calculate the contact parameters used in the TCR modeling. Then, the predictive model for TCR, which considered the combined effect of the morphology of bearing rings and the contact deformation of asperities, was proposed. Thermal equilibrium experiments were conducted to demonstrate the validity of the model. The results showed that the FEA model can accurately simulate the temperature field and thermal deformation of the Spindle System and that the FEA model was much more accurate than the traditional thermal model of the high-speed Spindle System which ignored TCR and bearing stiffness.
Hu Shi - One of the best experts on this subject based on the ideXlab platform.
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thermal error compensation based on genetic algorithm and artificial neural network of the shaft in the high speed Spindle System
Proceedings of the Institution of Mechanical Engineers Part B: Journal of Engineering Manufacture, 2017Co-Authors: Liang Zhao, Hu Shi, Xuesong Mei, Ju YangAbstract:To improve the accuracy, generality and convergence of thermal error compensation model based on traditional neural networks, a genetic algorithm was proposed to optimize the number of the nodes in the hidden layer, the weights and the thresholds of the traditional neural network by considering the shortcomings of the traditional neural networks which converged slowly and was easy to fall into local minima. Subsequently, the grey cluster grouping and statistical correlation analysis were proposed to group temperature variables and select thermal sensitive points. Then, the thermal error models of the high-speed Spindle System were proposed based on the back propagation and genetic algorithm–back propagation neural networks with practical thermal error sample data. Moreover, thermal error compensation equations of three directions and compensation strategy were presented, considering thermal elongation and radial tilt angles. Finally, the real-time thermal error compensation was implemented on the jig bore...
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Simulation and experimental study on the thermally induced deformations of high-speed Spindle System
Applied Thermal Engineering, 2015Co-Authors: Chi Ma, Xuesong Mei, Jun Yang, Liang Zhao, Hu ShiAbstract:Abstract In order to avoid the degeneration of high-speed Spindle's machining accuracy in actual machining caused by the uneven distribution of temperature field at the design stage, a three-dimensional (3D) finite element analysis (FEA) model, which considered the combined influence of thermal contact resistance (TCR) and bearing stiffness on the accuracy of simulation results, was proposed to conduct transient thermal-structure interactive analysis of motorized Spindles. And the method to calculate the boundary conditions used in the FEM model were discussed in detail, such as the heat loads, convective heat transfer, TCR and bearing stiffness. Based on the quasi-static mechanics analysis of rolling bearing, the transfer relationships among multiple variables in the equilibrium equation set of bearings were analyzed. Newton-Raphson algorithm, which regarded the contact angle as the iteration variable, was proposed to calculate the heat power and stiffness of bearings and improve the convergence of the algorithm, and the termination criteria of contact angle's searching trial calculation was proposed to improve the accuracy of the algorithm. The Weierstrass-Mandelbrot (W-M) function in fractal geometry was used to characterize the rough surface morphology of bearing rings. The fractal parameters were identified by the power spectrum method, and a contact deformation model of asperities was developed to calculate the contact parameters used in the TCR modeling. Then, the predictive model for TCR, which considered the combined effect of the morphology of bearing rings and the contact deformation of asperities, was proposed. Thermal equilibrium experiments were conducted to demonstrate the validity of the model. The results showed that the FEA model can accurately simulate the temperature field and thermal deformation of the Spindle System and that the FEA model was much more accurate than the traditional thermal model of the high-speed Spindle System which ignored TCR and bearing stiffness.
Bo Yang - One of the best experts on this subject based on the ideXlab platform.
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thermal structure interaction characteristics of a high speed Spindle bearing System
International Journal of Machine Tools & Manufacture, 2019Co-Authors: Shilong Wang, Sibao Wang, Bo YangAbstract:Abstract The neglection of thermal-structure interaction of high-speed Spindle System may lead to the modeling error of the thermal characteristics. To improve the modeling accuracy, the thermal-structure interaction mechanism was analyzed and the closed-loop iterative modeling method of thermal characteristics was proposed to modify the heat sources and thermal boundary conditions of the Spindle System in each substep. The heat generation of bearings and built-in motor, the convective coefficients and the thermal contact resistances (TCRs) of bearing joints were computed. The heat generation of bearings was calculated by the SKF bearing thermal model and the results were compared with that obtained by integral method. The heat generation of bearings was modified by considering the combined effect of the lubricant viscosity variation and thermally-induced preload of bearings. Moreover, a novel geometrical-mechanical-thermal model for TCRs was proposed by characterizing the rough surface morphology and by establishing the multi-scale contact mechanics of joint surfaces. To validate the effectiveness of the proposed method, the thermal characteristic experiments of the Spindle System were conducted under different rotational speeds. The results showed that the modeling errors in the temperature field and thermal deformation are reduced significantly and that this model has the ability of thermal error compensation.