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Vibration analysis of blade-disc coupled structure of compressor

WANG Chunjie, SONG Shunguang, ZONG Xiao

《能源前沿（英文）》 2008年 第2卷 第3期   页码 302-305 doi: 10.1007/s11708-008-0064-8

摘要： While a 3D assembly model of blade-disc structure was established, a finite element model for calculating the vibration characteristics during blade-disc coupling was built by taking into consideration the coupling action of contact stress between the blade and the disc. The vibration characteristics of the blade-disc coupling structure was calculated and analyzed using cycle analysis method with the aid of ANSYS software. The modeling experiment shows that this method is feasible for analyzing the rabbet assembly structure.

关键词： blade-disc coupling     assembly     experiment     vibration     blade-disc structure    

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Thermo-elastic extended meshfree method for fracture without crack tip enrichment

A. ASADPOUR

《结构与土木工程前沿（英文）》 2015年 第9卷 第4期   页码 441-447 doi: 10.1007/s11709-015-0319-5

摘要： This is the first manuscript presenting an extended meshfree method for thermo- elastic fracture which does not exploit a crack tip enrichment. The crack is modeled by partition of unity enrichment of the displacement and temperature field. Only a step function is employed that facilitates the implementation. To ensure that crack tip is at the correct position, a Lagrange multiplier field ahead of the crack tip is introduced along a line. The Lagrange multiplier nodal parameters are discretised with the available meshfree functions. Two benchmark examples illustrate the efficiency of the method.

关键词： meshfree method     thermo-elasticity    

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Optimal Timing and Recycling Operation Mode for Electro-Mechanical Products Active Remanufacturing

Wang Gao,Tao Li,Shi-tong Peng,Liang Wang,Hong-chao Zhang

《工程管理前沿（英文）》 2016年 第3卷 第2期   页码 115-122 doi: 10.15302/J-FEM-2016019

摘要： The uncertainties of remanufactured products in multi-life cycle service, such as injury and restoration process route, are comprehensively analyzed in the present study from perspectives of cost and the environment. Based on life cycle assessment method and the life cycle cost analysis, the optimal timing model of active remanufacturing for electro-mechanical products is established considering these uncertainties. In addition, regarding the active remanufacturing as its guidance, this study explores the economic efficiency and corresponding operation mode of electro-mechanical products when recycling in the optimal timing. To validate the optimal timing model for electro-mechanical products active remanufacturing, a specific type of product is taken as a case study with mathematical statistics method and Monte Carlo simulation.

关键词： electro-mechanical products     active remanufacturing     optimal timing     reverse logistics     recycling mode    

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Review: Tip-based vibrational spectroscopy for nanoscale analysis of emerging energy materials

Amun JARZEMBSKI, Cedric SHASKEY, Keunhan PARK

《能源前沿（英文）》 2018年 第12卷 第1期   页码 43-71 doi: 10.1007/s11708-018-0524-8

摘要： Vibrational spectroscopy is one of the key instrumentations that provide non-invasive investigation of structural and chemical composition for both organic and inorganic materials. However, diffraction of light fundamentally limits the spatial resolution of far-field vibrational spectroscopy to roughly half the wavelength. In this article, we thoroughly review the integration of atomic force microscopy (AFM) with vibrational spectroscopy to enable the nanoscale characterization of emerging energy materials, which has not been possible with far-field optical techniques. The discussed methods utilize the AFM tip as a nanoscopic tool to extract spatially resolved electronic or molecular vibrational resonance spectra of a sample illuminated by a visible or infrared (IR) light source. The absorption of light by electrons or individual functional groups within molecules leads to changes in the sample’s thermal response, optical scattering, and atomic force interactions, all of which can be readily probed by an AFM tip. For example, photothermal induced resonance (PTIR) spectroscopy methods measure a sample’s local thermal expansion or temperature rise. Therefore, they use the AFM tip as a thermal detector to directly relate absorbed IR light to the thermal response of a sample. Optical scattering methods based on scanning near-field optical microscopy (SNOM) correlate the spectrum of scattered near-field light with molecular vibrational modes. More recently, photo-induced force microscopy (PiFM) has been developed to measure the change of the optical force gradient due to the light absorption by molecular vibrational resonances using AFM’s superb sensitivity in detecting tip-sample force interactions. Such recent efforts successfully breech the diffraction limit of light to provide nanoscale spatial resolution of vibrational spectroscopy, which will become a critical technique for characterizing novel energy materials.

关键词： vibrational spectroscopy     atomic force microscopy     photo-thermal induced resonance     scanning near-field optical microscopy     tip-enhanced Raman spectroscopy     photo-induced force microscopy     molecular resonances     surface phonon polaritons     energy materials    

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Full-field dynamic strain reconstruction of an aero-engine blade from limited displacement responses

《机械工程前沿（英文）》 2023年 第18卷 第1期 doi: 10.1007/s11465-022-0731-1

摘要： Blade strain distribution and its change with time are crucial for reliability analysis and residual life evaluation in blade vibration tests. Traditional strain measurements are achieved by strain gauges (SGs) in a contact manner at discrete positions on the blades. This study proposes a method of full-field and real-time strain reconstruction of an aero-engine blade based on limited displacement responses. Limited optical measured displacement responses are utilized to reconstruct the full-field strain. The full-field strain distribution is in-time visualized. A displacement-to-strain transformation matrix is derived on the basis of the blade mode shapes in the modal coordinate. The proposed method is validated on an aero-engine blade in numerical and experimental cases. Three discrete vibrational displacement responses measured by laser triangulation sensors are used to reconstruct the full-field strain over the whole operating time. The reconstructed strain responses are compared with the results measured by SGs and numerical simulation. The high consistency between the reconstructed and measured results demonstrates the accurate strain reconstructed by the method. This paper provides a low-cost, real-time, and visualized measurement of blade full-field dynamic strain using displacement response, where the traditional SGs would fail.

关键词： aero-engine blade     displacement response     dynamic strain reconstruction     mode shape     strain gauge    

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New response surface model and its applications in aerodynamic optimization of axial compressor blade

LIU Xiaojia, NING Fangfei

《能源前沿（英文）》 2008年 第2卷 第4期   页码 541-549 doi: 10.1007/s11708-008-0077-3

摘要： A parametric method for the axial compressor 2D blade profiles is proposed in which the blade geometries are defined with the parameters commonly used for blade definition, which ensures that the geometric significance is clear and an unreasonable blade profile is not generated. Several illustrations are presented to show the fitting precision of the method. A novel response surface model is proposed which regards the objective distribution function in the vicinity of a sample as normal school, and then generates the response surface function in the whole design space by a linear combination of distribution functions of all the samples. Based on this model, a numerical aerodynamic optimization platform for the axial compressor 2D blade profiles is developed, by which aerodynamic optimization of two compressor blade profiles are presented.

关键词： definition     objective distribution     fitting precision     combination     numerical aerodynamic    

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Measurement and analysis of tip clearance unsteady flow spectrum in axial-flow fan rotor

LIU Bo, HOU Weimin, MA Changyou, WANG Yangang, ZHOU Qiang

《能源前沿（英文）》 2008年 第2卷 第4期   页码 448-452 doi: 10.1007/s11708-008-0088-0

摘要： The dynamic pressure measurement device and test technology are described in this study. The tip clearance unsteady flow development from the inlet to the outlet of an axial-flow rotor was revealed by analyzing pressure frequency spectrum acquired from measuring the unsteady pressure field of the tip endwall. The experiment provides test basis for thoroughly understanding the tip clearance unsteady flow and building interaction models of tip clearance flow and main flow.

关键词： development     endwall     unsteady pressure     pressure measurement     experiment    

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Dynamic characteristics of a shrouded blade with impact and friction

Xumin GUO, Jin ZENG, Hui MA, Chenguang ZHAO, Lin QU, Bangchun WEN

《机械工程前沿（英文）》 2020年 第15卷 第2期   页码 209-226 doi: 10.1007/s11465-019-0566-6

摘要： A simplified computational model of a twisted shrouded blade with impact and friction is established. In this model, the shrouded blade is simulated by a flexible Timoshenko beam with a tip-mass, and the effects of centrifugal stiffening, spin softening, and Coriolis force are considered. Impact force is simulated using a linear spring model, and friction force is generated by a tangential spring model under sticking state and a Coulomb friction model under sliding state. The proposed model is validated by a finite element model. Then, the effects of initial gap and normal preload, coefficient of friction, and contact stiffness ratio (the ratio of tangential contact stiffness to normal contact stiffness) on system vibration responses are analyzed. Results show that resonant peaks become inconspicuous and impact plays a dominant role when initial gaps are large between adjacent shrouds. By contrast, in small initial gaps or initial normal preloads condition, resonant speed increases sharply, and the optimal initial normal preloads that can minimize resonant amplitude becomes apparent. Coefficient of friction affects the optimal initial normal preload, but it does not affect vibration responses when the contact between shrouds is under full stick. System resonant amplitude decreases with the increase of contact stiffness ratio, but the optimal initial normal preload is unaffected.

关键词： twisted shrouded blade     dynamic analysis     impact     friction     separate–stick–slip motion    

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Effects of fuel combination and IVO timing on combustion and emissions of a dual-fuel HCCI combustion

Xin LIANG, Jianyong ZHANG, Zhongzhao LI, Jiabo ZHANG, Zhen HUANG, Dong HAN

《能源前沿（英文）》 2020年 第14卷 第4期   页码 778-789 doi: 10.1007/s11708-020-0698-8

摘要： This paper experimentally and numerically studied the effects of fuel combination and intake valve opening (IVO) timing on combustion and emissions of an n-heptane and gasoline dual-fuel homogeneous charge compression ignition (HCCI) engine. By changing the gasoline fraction (GF) from 0.1 to 0.5 and the IVO timing from –15°CA ATDC to 35°CA ATDC, the in-cylinder pressure traces, heat release behaviors, and HC and CO emissions were investigated. The results showed that both the increased GF and the retarded IVO timing delay the combustion phasing, lengthen the combustion duration, and decrease the peak heat release rate and the maximum average combustion temperature, whereas the IVO timing has a more obvious influence on combustion than GF. HC and CO emissions are decreased with reduced GF, advanced IVO timing and increased operational load.

关键词： homogeneous charge compression ignition     dual-fuel     n-heptane     gasoline     intake valve opening timing    

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Nonlinear dynamic behavior of rotating blade with breathing crack

Laihao YANG, Zhu MAO, Shuming WU, Xuefeng CHEN, Ruqiang YAN

《机械工程前沿（英文）》 2021年 第16卷 第1期   页码 196-220 doi: 10.1007/s11465-020-0609-z

摘要： This study aims at investigating the nonlinear dynamic behavior of rotating blade with transverse crack. A novel nonlinear rotating cracked blade model (NRCBM), which contains the spinning softening, centrifugal stiffening, Coriolis force, and crack closing effects, is developed based on continuous beam theory and strain energy release rate method. The rotating blade is considered as a cantilever beam fixed on the rigid hub with high rotating speed, and the crack is deemed to be open and close continuously in a trigonometric function way with the blade vibration. It is verified by the comparison with a finite element-based contact crack model and bilinear model that the proposed NRCBM can well capture the dynamic characteristics of the rotating blade with breathing crack. The dynamic behavior of rotating cracked blade is then investigated with NRCBM, and the nonlinear damage indicator (NDI) is introduced to characterize the nonlinearity caused by blade crack. The results show that NDI is a distinguishable indicator for the severity level estimation of the crack in rotating blade. It is found that severe crack (i.e., a closer crack position to blade root as well as larger crack depth) is expected to heavily reduce the stiffness of rotating blade and apparently result in a lower resonant frequency. Meanwhile, the super-harmonic resonances are verified to be distinguishable indicators for diagnosing the crack existence, and the third-order super-harmonic resonances can serve as an indicator for the presence of severe crack since it only distinctly appears when the crack is severe.

关键词： rotating blade     breathing crack     nonlinear vibration     nonlinear damage indicator    

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Life-cycle cost analysis of optimal timing of pavement preservation

Zilong WANG,Hao WANG

《结构与土木工程前沿（英文）》 2017年 第11卷 第1期   页码 17-26 doi: 10.1007/s11709-016-0369-3

摘要： Optimal application of pavement preservation or preventive maintenance is critical for highway agencies to allocate the limited budget for different treatments. This study developed an integrated life-cycle cost analysis (LCCA) model to quantify the impact of pavement preservation on agency cost and vehicle operation cost (VOC) and analyzed the optimal timing of preservation treatments. The international roughness index (IRI) data were extracted from the long-term pavement performance (LTPP) program specific pavement studies 3 (SPS-3) to determine the long-term effectiveness of preservation treatments on IRI deterioration. The traffic loading and the initial IRI value significantly affects life extension and the benefit of agency cost caused by pavement preservation. The benefit in VOC is one to two orders greater in magnitude as compared to the benefit in agency cost. The optimal timing calculated based on VOC is always earlier than the optimal timing calculated based on agency cost. There are considerable differences among the optimal timing of three preservation treatments.

关键词： pavement preservation     life-cycle cost analysis     agency cost     vehicle operation cost    

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Postprocessor development for ultrasonic cutting of honeycomb core curved surface with a straight blade

《机械工程前沿（英文）》 2023年 第18卷 第1期 doi: 10.1007/s11465-022-0729-8

摘要： When ultrasonically cutting honeycomb core curved parts, the tool face of the straight blade must be along the curved surface’s tangent direction at all times to ensure high-quality machining of the curved surface. However, given that the straight blade is a nonstandard tool, the existing computer-aided manufacturing technology cannot directly realize the above action requirement. To solve this problem, this paper proposed an algorithm for extracting a straight blade real-time tool face vector from a 5-axis milling automatically programmed tool location file, which can realize the tool location point and tool axis vector conversion from the flat end mill to the straight blade. At the same time, for the multi-solution problem of the rotation axis, the dependent axis rotation minimization algorithm was introduced, and the spindle rotation algorithm was proposed for the tool edge orientation problem when the straight blade is used to machine the curved part. Finally, on the basis of the MATLAB platform, the dependent axis rotation minimization algorithm and spindle rotation algorithm were integrated and compiled, and the straight blade ultrasonic cutting honeycomb core postprocessor was then developed. The model of the machine tool and the definition of the straight blade were conducted in the VERICUT simulation software, and the simulation machining of the equivalent entity of the honeycomb core can then be realized. The correctness of the numerical control program generated by the postprocessor was verified by machining and accuracy testing of the two designed features. Observation and analysis of the simulation and experiment indicate that the tool pose is the same under each working condition, and the workpieces obtained by machining also meet the corresponding accuracy requirements. Therefore, the postprocessor developed in this paper can be well adapted to the honeycomb core ultrasonic cutting machine tool and realize high-quality and high-efficient machining of honeycomb core composites.

关键词： honeycomb core     straight blade     ultrasonic cutting     tool pose     postprocessor    

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Numerical simulation of a new hollow stationary dehumidity blade in last stage of steam turbine

Youmin HOU, Danmei XIE, Wangfan LI, Xinggang YU, Yang SHI, Hanshi QIN

《能源前沿（英文）》 2011年 第5卷 第3期   页码 288-296 doi: 10.1007/s11708-011-0160-z

摘要： As a result of adopting saturation steam and long blade, problems of water erosion of last stage blade for steam turbine become more prominent. In order to improve the operation reliability and efficiency of steam turbine, it is necessary to investigate the nonequilibrium condensing wet steam two phase flow and the dehumidity method. A wet steam model with user defined function based on FLUENT software was investigated to simulate the steam condensing flow in the cascades. The simulation consequences show that the pressure variations in simulation depict a good agreement with the experiment data. On the basis of the discrete phase model simulation results and experiment data, the efficiency of existing dehumidity blade with suction slot was calculated. A new stationary dehumidity blade was designed to elevate the dehumidity efficiency: the efficiency in the suction surface was increased by 21.5%, and that in the pressure surface was increased by 12.2%.

关键词： steam turbine     hollow stationary blade     dehumidity     numerical simulation    

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Mobile platform for hydraulic turbine blade repair robot

GUI Zhongcheng, CHEN Qiang, SUN Zhenguo, ZHANG Wenzeng, LIU Kang

《机械工程前沿（英文）》 2008年 第3卷 第2期   页码 164-169 doi: 10.1007/s11465-008-0035-0

摘要： The wall-climbing mobile platform (MP) of a robot for repairing a hydraulic turbine blade onsite is developed. The MP is equipped with ferromagnetic adhesive devices and can work on a spatial curved surface. The contradiction between mobility and load-bearing ability is analyzed, and the problem of self-adaptation to the curved face is solved using differential-driven wheeled locomotion with ferromagnetic adhesive devices. The platform adheres to the blade surface through the force provided by the ferromagnetic devices, and a certain gap exists between the magnetic devices and the blade’s surface. A mechanism of three revolution degrees of freedom, which connects the magnetic devices with the platform’s chassis, is developed to make the platform self-adapt to the complex curved surface of the turbine blade. A proof-of-principle prototype has been manufactured, and experiments prove the success of the MP. The payload of the zero-turn-radius MP with excellent maneuverability exceeds 80 kg. The platform can automatically adapt to complex spatial surfaces, which satisfy the requirements of a hydraulic turbine blade in-situ repair robot.
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Stress field near circular-arc interface crack tip based on electric saturation concept

Longchao DAI, Xinwei WANG

《机械工程前沿（英文）》 2009年 第4卷 第3期   页码 320-325 doi: 10.1007/s11465-009-0042-9

摘要： Within the framework of nonlinear electroelasticity, the anti-plane problem of a circular-arc interfacial crack between a circular piezoelectric inhomogeneity and an infinite piezoelectric matrix subjected to a far-field uniform loading is investigated by an electrical strip saturation model, the complex variable method, and the method of analytical continuation. Explicit closed form expressions for the complex potentials in both the matrix and the inclusion, and the stress intensity factor at the crack tip are presented. Comparison with some related solutions based on the linear electroelastic theory shows the validity of the present solutions

关键词： piezoelectric material     arc crack     strip saturation     stress intensity factor    

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标题 作者 时间 类型 操作

Vibration analysis of blade-disc coupled structure of compressor

WANG Chunjie, SONG Shunguang, ZONG Xiao

期刊论文

Thermo-elastic extended meshfree method for fracture without crack tip enrichment

A. ASADPOUR

期刊论文

Optimal Timing and Recycling Operation Mode for Electro-Mechanical Products Active Remanufacturing

Wang Gao,Tao Li,Shi-tong Peng,Liang Wang,Hong-chao Zhang

期刊论文

Review: Tip-based vibrational spectroscopy for nanoscale analysis of emerging energy materials

Amun JARZEMBSKI, Cedric SHASKEY, Keunhan PARK

期刊论文

Full-field dynamic strain reconstruction of an aero-engine blade from limited displacement responses

期刊论文

New response surface model and its applications in aerodynamic optimization of axial compressor blade

LIU Xiaojia, NING Fangfei

期刊论文

Measurement and analysis of tip clearance unsteady flow spectrum in axial-flow fan rotor

LIU Bo, HOU Weimin, MA Changyou, WANG Yangang, ZHOU Qiang

期刊论文

Dynamic characteristics of a shrouded blade with impact and friction

Xumin GUO, Jin ZENG, Hui MA, Chenguang ZHAO, Lin QU, Bangchun WEN

期刊论文

Effects of fuel combination and IVO timing on combustion and emissions of a dual-fuel HCCI combustion

Xin LIANG, Jianyong ZHANG, Zhongzhao LI, Jiabo ZHANG, Zhen HUANG, Dong HAN

期刊论文

Nonlinear dynamic behavior of rotating blade with breathing crack

Laihao YANG, Zhu MAO, Shuming WU, Xuefeng CHEN, Ruqiang YAN

期刊论文

Life-cycle cost analysis of optimal timing of pavement preservation

Zilong WANG,Hao WANG

期刊论文

Postprocessor development for ultrasonic cutting of honeycomb core curved surface with a straight blade

期刊论文

Numerical simulation of a new hollow stationary dehumidity blade in last stage of steam turbine

Youmin HOU, Danmei XIE, Wangfan LI, Xinggang YU, Yang SHI, Hanshi QIN

期刊论文

Mobile platform for hydraulic turbine blade repair robot

GUI Zhongcheng, CHEN Qiang, SUN Zhenguo, ZHANG Wenzeng, LIU Kang

期刊论文

Stress field near circular-arc interface crack tip based on electric saturation concept

Longchao DAI, Xinwei WANG

期刊论文