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Wei Sun - One of the best experts on this subject based on the ideXlab platform.
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A cyclic symmetric model for the investigation of vibration reduction of Hard-Coating blisk
Engineering Computations, 2020Co-Authors: Wei Sun, Junnan Gao, Shuai Yang, Xianfei YanAbstract:Purpose It is very important to create a useful cyclic symmetric model for the investigation of the vibration reduction effect of Hard-Coating blisk. This study aims to develop a cyclic symmetry algorithm which can determine the mode of blisk in the sector coordinate system directly. Design/methodology/approach Using the exponential and real quasi-equivalent Fourier matrices, the formulas for solving the sector mode were derived, and the relationship between the two kinds of sector modes was also discussed. Based on the proposed cyclic symmetry algorithm, the vibration characteristics of an academic blisk were solved, and the formulas for solving the natural characteristics and vibration responses of the coated blisk were given. Findings A blisk with NiCrAlCoY+YSZ Hard Coating on both sides of each blade was chosen as a case to demonstrate the presented method. Based on the verification analysis model, the influences of Coating thickness on the vibration reduction effect of the blisk were discussed. The results show that the Hard Coating has good vibration reduction effect on the blisk even the Coating thickness is very thin and the vibration reduction effect of Hard Coating in the high frequency range is obviously better than that in the low frequency range. Originality/value As a large number of reduced order modeling methods of blisk are implemented based on the sector modes, the proposed method which can obtain the sector modes directly will significantly improve the efficiency of dynamic modeling and analysis of the coated blisk structure.
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The equivalent modeling of Hard-Coating blisk based on mistuning identification
Aerospace Science and Technology, 2019Co-Authors: Wei Sun, Junnan Gao, Xianfei YanAbstract:Abstract In order to accurately capture the dynamic characteristics of the actual Hard-Coating blisk and reduce the computation cost, an equivalent finite element modeling method based on mistuning identification was proposed in this study. In this modeling method, virtual single-layer material blades were used to replace the Hard-Coating blades of multi-layer structure. Meanwhile, based on the mistuning identification theory, the equivalent elastic modulus, as the key parameter, was determined. In addition, the methods to generate the other two equivalent parameters (equivalent density and equivalent Poisson's ratio) were also proposed. Moreover, through the numerical and actual cases, the equivalent models were created by the proposed method respectively and the modal data of the equivalent models was compared and analyzed. Compared with the traditional finite element model (FEM), the structure of the equivalent model is simpler and the number of elements is smaller, however, for the modal data, the comparison results showed good correspondence of the equivalent model and the actual Hard-Coating blisk.
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Nonlinear finite element modeling and vibration analysis of the blisk deposited strain-dependent Hard Coating
Mechanical Systems and Signal Processing, 2019Co-Authors: Feng Gao, Wei SunAbstract:Abstract This study focuses on the nonlinear vibration analysis of the integrally bladed disk (the blisk for short) deposited strain-dependent Hard Coating (also known as the Hard-Coating blisk) and the influence of Hard Coating on dynamics of the blisk. The high-order polynomials are employed to characterize the experimental mechanical parameters of the strain-dependent Hard Coating. The strain-dependent model of Hard-Coating blisk is constructed by the energy-based FE (finite element) method consisting of the complex modulus and composite Mindlin plate theory. And, a specified iterative solution procedure based on the Newton-Raphson method is proposed to solve strain-dependent dynamics. A specific benchmark of an academic blisk deposited NiCoCrAlY + YSZ Hard Coating on blades is chosen to perform numerical calculation and experimental test, and the specific comparisons between both numerical and experimental results are then conducted to validate the developed FE model. Moreover, the specific influence of Hard Coating with or without strain-dependent manner on the blade and blisk are investigate here.
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Free vibration analysis of the Hard-Coating splitter blisk using the energy-based finite element method:
Proceedings of the Institution of Mechanical Engineers Part C: Journal of Mechanical Engineering Science, 2019Co-Authors: Feng Gao, Wei SunAbstract:This paper presents the free vibration analysis of the Hard-Coating splitter blisk (known as the splitter blisk deposited Hard Coating) and the damping-improved performance of the Hard Coating for ...
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Optimal design of the Hard-Coating blisk using nonlinear dynamic analysis and multi-objective genetic algorithm
Composite Structures, 2019Co-Authors: Feng Gao, Wei Sun, Junnan GaoAbstract:Abstract By the nonlinear FE (finite element) analysis and multi-objective genetic algorithm, the optimal design of the integrally bladed disk (blisk) deposited nonlinear Hard Coating (Hard-Coating blisk) was investigated in this study. Considering the strain-dependent manner of the Hard Coating, the nonlinear dynamic modelling and forced vibration analysis of the Hard-Coating blisk were conducted by the energy-based FE method and the unified iterative calculation based on Newton-Raphson method, respectively. The reference point based NSGA-II (non-dominated sorting genetic algorithm) was used to solve multi-objective optimization problems of the Hard-Coating blisk, and the optimization results are obtained as Pareto front. Particularly, an academic blisk with NiCoCrAlY + YSZ Hard Coating was choose as the benchmark to conduct the bi-objective and triple-objective optimization. The results reveal that the designing parameters of the Hard Coating are constrained mutually, the reference data can be obtained according to the practical requirements, and the specific data located at the “turning point” can balance all aspects of design performance.
Dongfeng Diao - One of the best experts on this subject based on the ideXlab platform.
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finite element analysis of the effect of interfacial roughness and adhesion strength on the local delamination of Hard Coating under sliding contact
Tribology International, 2006Co-Authors: Dongfeng Diao, Akira KandoriAbstract:The interfacial roughness and the adhesion strength are very important for making a high-quality Coating for friction and wear applications. In order to obtain a quantitative understanding concerning the effect of the two factors on the local delamination of Hard Coatings, finite element analyses concerning the maximum shear stress in a Hard Coating with various kinds of interfacial roughness and adhesion strength were made under low and high frictional conditions. As a result, local delamination maps for the identification of the local delamination of Hard Coatings were obtained as a function of the shear strength ratio of Coating to substrate and the ratio of Coating thickness to half-contact width. Also, the critical contact pressure required to produce local delamination of Hard Coatings is given.
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finite element analysis on local yield map and critical maximum contact pressure for yielding in Hard Coating with an interlayer under sliding contact
Tribology International, 1999Co-Authors: Dongfeng DiaoAbstract:Abstract Micro-crack in the Hard Coating initiates usually from the local yield position. To prevent the crack to occur, the most important criterion is to satisfy the condition that the von Mises stress is less than the yield strength of material. In this paper, the local yield map showing the yielding position are introduced by using the finite element method and the criterion. The critical maximum contact pressures for yielding at the different positions were calculated by using the Coating thickness, friction coefficient and the yield strength, where a critical range of yield strength ratio for the transition of yielding positions was found for 0.4∼0.5. When the yield strength ratio is less than the range, yielding initiates from the interlayer and when the ratio is larger than the range, yielding initiates at the surface for high friction coefficient and in the base for low friction coefficient.
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The maximum tensile stres on a Hard Coating under sliding friction
Tribology International, 1994Co-Authors: Dongfeng Diao, Koji Kato, K HayashiAbstract:Abstract In the friction of a Hard Coating the maximum tensile stress in the sliding direction generated at the friction surface is important for predicting crack propagation in the Coating. The finite element method is employed to evaluate the stress field in the Hard Coating and the substrate under frictional loads, and the ratio between the values of maximum tensile stress and the maximum contact pressure is calculated under various contact conditions. Finally, a simple equation is introduced for the calculation of the maximum tensile stress at the friction surface. This equation is a function of friction coefficient, maximum contact pressure, Coating thickness, contact width and elastic moduli of Coating and substrate, and gives the value of the maximum tensile stress which is affected by the existence of the substrate.
Feng Gao - One of the best experts on this subject based on the ideXlab platform.
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Passive Vibration Reduction Analysis of the Mistuned Blisk Deposited Hard Coating Using Modified Reduced-Order Model
THE Coatings, 2019Co-Authors: Feng Gao, Xiuting LiuAbstract:To improve the reliability and safety of the mistuned blisk (integrally bladed disk), a novel strategy for passive vibration reduction by the Hard Coating was developed, and the vibration and damping characteristics of the HCM (Hard-Coating mistuned) blisk were investigated in this work. Firstly, by the proposed criterion called FDSD (frequency difference and its standard deviation), a classical reduced-order model established by the component mode synthesis method was modified to carry out modal analysis for high computational efficiency. Then, forced vibration responses of the HCM blisk were achieved by the Rayleigh damping model. Next, a specific benchmark of a mistuned blisk deposited NiCoCrAlY + YSZ Hard Coating was chosen to conduct numerical calculations, and the results were compared with those obtained from the FOM (full-order model) and experimental test, respectively. Finally, the influence of the Hard Coating and Coating thickness on the mistuned blisk were investigated, in particular.
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Nonlinear finite element modeling and vibration analysis of the blisk deposited strain-dependent Hard Coating
Mechanical Systems and Signal Processing, 2019Co-Authors: Feng Gao, Wei SunAbstract:Abstract This study focuses on the nonlinear vibration analysis of the integrally bladed disk (the blisk for short) deposited strain-dependent Hard Coating (also known as the Hard-Coating blisk) and the influence of Hard Coating on dynamics of the blisk. The high-order polynomials are employed to characterize the experimental mechanical parameters of the strain-dependent Hard Coating. The strain-dependent model of Hard-Coating blisk is constructed by the energy-based FE (finite element) method consisting of the complex modulus and composite Mindlin plate theory. And, a specified iterative solution procedure based on the Newton-Raphson method is proposed to solve strain-dependent dynamics. A specific benchmark of an academic blisk deposited NiCoCrAlY + YSZ Hard Coating on blades is chosen to perform numerical calculation and experimental test, and the specific comparisons between both numerical and experimental results are then conducted to validate the developed FE model. Moreover, the specific influence of Hard Coating with or without strain-dependent manner on the blade and blisk are investigate here.
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Free vibration analysis of the Hard-Coating splitter blisk using the energy-based finite element method:
Proceedings of the Institution of Mechanical Engineers Part C: Journal of Mechanical Engineering Science, 2019Co-Authors: Feng Gao, Wei SunAbstract:This paper presents the free vibration analysis of the Hard-Coating splitter blisk (known as the splitter blisk deposited Hard Coating) and the damping-improved performance of the Hard Coating for ...
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Optimal design of the Hard-Coating blisk using nonlinear dynamic analysis and multi-objective genetic algorithm
Composite Structures, 2019Co-Authors: Feng Gao, Wei Sun, Junnan GaoAbstract:Abstract By the nonlinear FE (finite element) analysis and multi-objective genetic algorithm, the optimal design of the integrally bladed disk (blisk) deposited nonlinear Hard Coating (Hard-Coating blisk) was investigated in this study. Considering the strain-dependent manner of the Hard Coating, the nonlinear dynamic modelling and forced vibration analysis of the Hard-Coating blisk were conducted by the energy-based FE method and the unified iterative calculation based on Newton-Raphson method, respectively. The reference point based NSGA-II (non-dominated sorting genetic algorithm) was used to solve multi-objective optimization problems of the Hard-Coating blisk, and the optimization results are obtained as Pareto front. Particularly, an academic blisk with NiCoCrAlY + YSZ Hard Coating was choose as the benchmark to conduct the bi-objective and triple-objective optimization. The results reveal that the designing parameters of the Hard Coating are constrained mutually, the reference data can be obtained according to the practical requirements, and the specific data located at the “turning point” can balance all aspects of design performance.
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Forced vibration analysis of the Hard-Coating blisk considering the strain-dependent manner of the Hard-Coating damper
Aerospace Science and Technology, 2018Co-Authors: Feng Gao, Wei Sun, Junnan GaoAbstract:Abstract This paper focuses on the passive vibration reduction of the blisk by the Hard-Coating damper, and investigates the nonlinear dynamics of the Hard-Coating blisk. Based on the discrete values obtained by the testing, the high-order polynomials are used to characterize the mechanical parameters of the Hard-Coating damper considering its strain-dependent manner. The boundary conditions and continuity conditions of the disk and the Hard-Coating blades are satisfied by introducing the artificial springs at their interface. The dynamic model of the Hard-Coating blisk is constructed by an analytical energy-based approach. An iterative solution procedure based on the Newton–Raphson method is developed to obtain dynamic characteristics of the Hard-Coating blisk. An academic blisk deposited NiCoCrAlY + YSZ Hard Coating is selected as the benchmark case to conduct the nonlinear numerical calculation, and the obtained results are compared with those obtained by the experimental test. In particular, the specific influence of the Hard-Coating damper and the unique strain-dependent manner on the vibration characteristics of the blisk are investigated respectively in terms of the resonant frequencies and corresponding responses.
Yue Zhang - One of the best experts on this subject based on the ideXlab platform.
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analytical analysis of forced vibration of the Hard Coating cylindrical shell with material nonlinearity and elastic constraint
Composite Structures, 2018Co-Authors: Yue Zhang, Jian YangAbstract:Abstract In this paper, the nonlinear vibration characteristics of the Hard-Coating cylindrical shell with the base excitation and un-classical elastic constraint are investigated based on the Rayleigh-Ritz method. A continual variable stiffness elastic constraint is presented to introduce the actual uneven distribution of connection stiffness into the analytical vibration analysis. The nonlinear governing equations of motion are formulated by the Love’s first approximation theory and von Karman-type nonlinear strain-displacement relationship. The admissible displacement functions are constructed by the Gram-Schmidt orthogonal polynomials. To effectively consider the effects of the strain dependences of storage modulus and loss factor of Hard Coating on the vibration characteristics of the shell, a modified domain decomposition method is employed to determine the equivalent strain of Hard Coating under the action of base excitation. By extending the Newton-Raphson iterative scheme, a unified iterative solution method is developed for solving the nonlinear resonant frequencies and responses of the Hard-Coating cylindrical shell. The numerical and experimental examples of the cylindrical shell coated with NiCoCrAlY + YSZ are performed to validate the accuracy and reliability of the developed analytical model. The mechanism of soft nonlinearity displayed in the amplitude-frequency curves of the Hard-Coating cylindrical shell is discussed as well.
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Nonlinear vibration analysis of a Hard-Coating cylindrical shell with elastic constraints by finite element method
Nonlinear Dynamics, 2017Co-Authors: Yue Zhang, Wei Sun, Jian Yang, Qingkai HanAbstract:In this paper, the nonlinear vibration characteristics of the Hard-Coating cylindrical shell with base excitation are investigated based on a composite cylindrical shell element of 4 nodes and 48 degrees of freedom. An elastic constraint with continuous variable stiffness is constructed to simulate the real boundary conditions of the shell. Considering the material damping, the equivalent viscous damping and the strain dependencies of storage modulus and loss factor of Hard Coating, a unified nonlinear iterative solution method is developed for the vibration analysis. As an example to demonstrate the feasibility of the developed model, the experimental test of the cylindrical shell coated with NiCoCrAlY $$+$$ YSZ Hard Coating is implemented. The results of the developed model and experimental test show a good consistency, and both indicate that the Hard-Coating cylindrical shell with strain dependence has the unique properties of soft nonlinearity compared with the linear results.
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Analytical analysis of vibration characteristics for the Hard-Coating cantilever laminated plate:
Proceedings of the Institution of Mechanical Engineers Part G: Journal of Aerospace Engineering, 2017Co-Authors: Wei Sun, Xiaozhou Liu, Yue ZhangAbstract:For laminated plate served in high temperature and high corrosion environment, Hard Coating can be applied to suppress destructive vibration. While the creation of the dynamic model of Hard-Coating...
Dongchan Jang - One of the best experts on this subject based on the ideXlab platform.
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flexible Hard Coating glass like wear resistant yet plastic like compliant transparent protective Coating for foldable displays
Advanced Materials, 2017Co-Authors: Gwangmun Choi, Dahye Shin, Jihoon Ko, Hyeongyun Im, Junho Jang, Dongchan JangAbstract:A flexible Hard Coating for foldable displays is realized by the highly cross-linked siloxane hybrid using structure–property relationships in organic–inorganic hybridization. Glass-like wear resistance, plastic-like flexibility, and highly elastic resilience are demonstrated together with outstanding optical transparency. It provides a framework for the application of siloxane hybrids in protective Hard Coatings with high scratch resistance and flexibility for foldable displays.
