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International Journal of Minerals,Metallurgy and Materials 2025年第1期32卷 147-153页

作者： Junjie Li Wenbo Yu Zhenyu Sun Weichen Zheng Liangwei Zhang Yanling Xue Wenning Liu Shoumei Xiong Center of Materials Science and engineering School of Mechanical and Electronic Control EngineeringBeijing Jiaotong UniversityBeijing 100044China Traffic&Transportation engineering Central South UniversityChangsha 410075China Shanghai Synchrotron Radiation Facility Shanghai Advanced Research InstituteChinese Academy of SciencesShanghai 201204China school of Materials Science and engineering Tsinghua UniversityBeijing 100084China

High pressure die casting(HPDC)AlSi10Mn Mg alloy castings are widely used in the automobile *** can optimize the mechanical properties of castings through heat treatment,while the release of thermal stress arouses the deformation of large integrated ***,the development of non-heat treatment Al alloys is becoming the hot *** addition,HPDC contains externally solidified crystals(ESCs),which are detrimental to the mechanical properties of *** achieve high strength and toughness of non-heat treatment die-casting Al-Si alloy,we used AlSi9Mn alloy as matrix with the introduction of Zr,Ti,Nb,and *** influences on ESCs and mechanical properties were systematically investigated through three-dimensional reconstruction and thermodynamic *** results reveal that the addition of Ti increased ESCs'size and porosity,while the introduction of Nb refined ESCs and decreased ***,large-sized Al_3(Zr,Ti)phases formed and degraded the mechanical *** introduction of Ce resulted in the poisoning effect and reduced mechanical properties.

关键词： aluminium alloy high-pressure die-casting externally solidified crystals non-heat treatment

Bearing Fault Diagnosis Based on the Markov Transition Field and SE-IShufflenetV2 Model

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Structural Durability & Health Monitoring 2025年第1期19卷 125-144页

作者： Chaozhi Cai Tiexin Xu Jianhua Ren Yingfang Xue school of mechanical and Equipment engineering Hebei University of EngineeringHandan056038China

A bearing fault diagnosis method based on the Markov transitionﬁeld(MTF)and SEnet(SE)-IShufﬂenetV2 model is proposed in this paper due to the problems of complex working conditions,low fault diagnosis accuracy,and poor generalization of rolling ***,MTF is used to encode one-dimensional time series vibration sig-nals and convert them into time-dependent and unique two-dimensional feature ***,the generated two-dimensional dataset is fed into the SE-IShufﬂenetV2 model for training to achieve fault feature extraction and classiﬁ*** paper selects the bearing fault datasets from Case Western Reserve University and Paderborn University to experimentally verify the effectiveness and superiority of the proposed *** generalization performance of the proposed method is tested under the variable load condition and different signal-to-noise ratios(SNRs).The experimental results show that the average accuracy of the proposed method under different working conditions is 99.2%without adding *** accuracy under different working conditions from 0 to 1 HP is 100%.When the SNR is 0 dB,the average accuracy of the proposed method can still reach 98.7%under varying working ***,the bearing fault diagnosis method proposed in this paper is characterized by high accuracy,strong anti-noise ability,and ***,the proposed method can also overcome the inﬂuence of variable working conditions on diagnosis accuracy,providing method support for the accurate diagnosis of bearing faults under strong noise and variable working conditions.

关键词： Bearings Markov transitionﬁeld SE-IShufﬂenetV2

Revealing and predicting the long-term biomechanical response of orthokeratology by developing a patient-specific computational model

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Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 156-168页

作者： Yifeng Li Zhuoran Yang Ziming Yan Huibin Shi Zhanli Liu Kaijie Wang Department of engineering Mechanics School of Aerospace Engineering Tsinghua University Beijing Tongren Eye Center Beijing Tongren Hospital Capital Medical University Beijing Ophthalmology & Visual Sciences Key Lab

Orthokeratology(OK) is widely used for effective myopia correction and control. However, the incomplete understanding of its biomechanical mechanisms makes OK lens fitting rely heavily on clinician judgment, complicating accurate predictions of treatment outcomes. In this paper, we performed clinical experiments and numerical analysis to study corneal deformation modes and long-term changes in central corneal thickness. Clinical experiments were conducted on 194 Chinese myopic patients under OK treatment for 3 months. Based on the experimental data, a patient-specific computational biomechanical model for OK was established and validated. Specifically, the anisotropic mechanical properties of the cornea were incorporated into the model to describe the significant difference between its shear modulus(29.5 kPa) and tensile modulus(768.4 kPa). Additionally, a viscohyperelastic material model with a prolonged corneal relaxation time of 5.6 h was developed to capture the long-term deformation response. The results show that corneal thickness reduction in OK is primarily due to out-of-plane shear deformation,influenced by the cornea's low shear resistance. Modeling the extended corneal relaxation time is crucial for predicting long-term biomechanical responses. The computational model effectively captures long-term changes in central corneal thickness, potentially improving OK lens fitting accuracy.

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Bioinspired Passive Tactile Sensors Enabled by Reversible Polarization of Conjugated Polymers

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Nano-Micro Letters 2025年第1期17卷 361-377页

作者： Feng He Sitong Chen Ruili Zhou Hanyu Diao Yangyang Han Xiaodong Wu school of mechanical engineering Sichuan UniversityChengdu 610065People’s Republic of China school of Software engineering Chongqing University of Posts and TelecommunicationsChongqing 400065People’s Republic of China State Key Laboratory of Polymer Materials engineering Sichuan UniversityChengdu 610065People’s Republic of China

Tactile perception plays a vital role for the human body and is also highly desired for smart prosthesis and advanced *** to active sensing devices,passive piezoelectric and triboelectric tactile sensors consume less power,but lack the capability to resolve static ***,we address this issue by utilizing the unique polarization chemistry of conjugated polymers for the first time and propose a new type of bioinspired,passive,and bio-friendly tactile sensors for resolving both static and dynamic ***,to emulate the polarization process of natural sensory cells,conjugated polymers(including poly(3,4-ethylenedioxythiophen e):poly(styrenesulfonate),polyaniline,or polypyrrole)are controllably polarized into two opposite states to create artificial potential *** controllable and reversible polarization process of the conjugated polymers is fully in situ ***,a micro-structured ionic electrolyte is employed to imitate the natural ion channels and to encode external touch stimulations into the variation in potential difference *** with the currently existing tactile sensing devices,the developed tactile sensors feature distinct characteristics including fully organic composition,high sensitivity(up to 773 mV N^(−1)),ultralow power consumption(nW),as well as superior *** demonstrations,both single point tactile perception(surface texture perception and material property perception)and two-dimensional tactile recognitions(shape or profile perception)with high accuracy are successfully realized using self-defined machine learning *** tactile sensing concept innovation based on the polarization chemistry of conjugated polymers opens up a new path to create robotic tactile sensors and prosthetic electronic skins.

关键词： Passive tactile sensors Reversible polarization of conjugated polymers Tactile perception Machine learning algorithm Object recognition

Dynamic modeling of a three-dimensional braided composite thin plate considering braiding directions

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Applied Mathematics and Mechanics(English Edition) 2025年第01期 123-138页

作者： Chentong GAO Huiyu SUN Jianping GU W.M.HUANG College of aerospace engineering Nanjing University of Aeronautics and Astronautics school of mechanical and aerospace engineering Nanyang Technological University Jiangsu Key Laboratory of Advanced Structural Materials and Application Technology School of Materials Science and EngineeringNanjing Institute of Technology

Currently, there are a limited number of dynamic models available for braided composite plates with large overall motions, despite the incorporation of three-dimensional(3D) braided composites into rotating blade components. In this paper, a dynamic model of 3D 4-directional braided composite thin plates considering braiding directions is established. Based on Kirchhoff's plate assumptions, the displacement variables of the plate are expressed. By incorporating the braiding directions into the constitutive equation of the braided composites, the dynamic model of the plate considering braiding directions is obtained. The effects of the speeds, braiding directions, and braided angles on the responses of the plate with fixed-axis rotation and translational motion, respectively, are investigated. This paper presents a dynamic theory for calculating the deformation of 3D braided composite structures undergoing both translational and rotational motions. It also provides a simulation method for investigating the dynamic behavior of non-isotropic material plates in various applications.

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Effects of Momentum Ratio and Weber Number on Spray Half Angles of Liquid Controlled Pintle Injector

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Journal of Thermal Science 2015年第1期24卷 37-43页

作者： Min Son Kijeong Yu Jaye Koo Oh Chae Kwon Jeong Soo Kim Korea aerospace University school of aerospace and mechanical engineering Korea Aerospace University school of mechanical engineering Sungkyunkwan University Department of mechanical engineering Pukyong National University

A pintle injector is advantageous for throttling a liquid rocket engine and reducing engine weight. This study ex- plores the effects of momentum ratio and Weber number at various injection conditions on spray characteristics of the pintle injector for liquid-gas propellants. A liquid sheet is injected from a center pintle nozzle and it is broken by a gas jet from an annular gap. The pressure drops of propellants, and the pintle opening distance were consi- dered as control variables; using 0.1 -1.0 as a bar for the pressure drop of the liquid injection, a 0.01-4）.2 bar for the pressure drop of gas jet and a 0.2 - 1.0 mm for the pintle opening distance. The discharge coefficient was de- creased linearly before the pintle opening distance of 0.75 mm and then, the coefficient was slightly increased. Spray images were captured by a CMOS camera with high resolution. Then, the shadow and reflected images were analyzed. Spray distributions were measured by a pattemator with an axial distance of 50 mm from a pintle tip. Finally, the spray half angles had an exponentially decreasing correlation as a momentum ratio divided by the Weber number. Also, the spray half angles from the spray distribution were underestimated compared to those measured from the captured images.

关键词： Pintle Injector Spray Half Angle Spray Distribution Visualization

Disintegration Process and Performance of a Coaxial Porous Injector

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Journal of Thermal Science 2016年第5期25卷 394-401页

作者： Keonwoong Lee Dohun Kim Jaye Koo Graduate school Korea Aerospace University school of aerospace and mechanical engineering Korea Aerospace University

In order to understand the breakup performance of coaxial porous injectors,the sprays of coaxial porous injectors with two different porous material cylinder lengths were compared with those of conventional shear coaxial *** allow comparison,the wall injection lengths were designed to be equivalent to the value of the recess *** flow sprays were visualized using back-lit photography methods and analyzed quantitatively with a laser diffraction apparatus,in order to study the effects of the momentum flux ratio and Weber number on the breakup for each type of *** case of the shear coaxial injector,the large liquid core was observed in low air mass flow rate ***,the destabilization of the liquid jet from the coaxial porous injector is almost complete within the inner region,near the injector face ***,better breakup performance in low gas flow rate condition was obtained when the porous cylinder length decreased,while the shear coaxial injectors showed better breakup efficiency when the recess length *** conclusion,the different breakup process caused by the radial momentum in the inner region of the porous injector disintegrated the liquid core.

关键词： Coaxial porous injector Sauter mean diameter Droplet size distribution

Ultra‑High Sensitivity Anisotropic Piezoelectric Sensors for Structural Health Monitoring and Robotic Perception

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Nano-Micro Letters 2025年第2期17卷 432-446页

作者： Hao Yin Yanting Li Zhiying Tian Qichao Li Chenhui Jiang Enfu Liang Yiping Guo State Key Laboratory of Metal Matrix Composites School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai 200240People’s Republic of China Beijing Vacuum Electronics Research Institute Beijing 100015People’s Republic of China Fundamental Science On Vibration Shock and Noise LaboratoryState Key Laboratory of Mechanical System and VibrationSchool of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai 200240People’s Republic of China

Monitoring minuscule mechanical signals,both in magnitude and direction,is imperative in many application scenarios,e.g.,structural health monitoring and robotic sensing ***,the piezoelectric sensor struggles to satisfy the requirements for directional recognition due to the limited piezoelectric coefficient matrix,and achieving sensitivity for detecting micrometer-scale deformations is also ***,we develop a vector sensor composed of lead zirconate titanate-electronic grade glass fiber composite filaments with oriented arrangement,capable of detecting minute anisotropic *** as-prepared vector sensor can identify the deformation directions even when subjected to an unprecedented nominal strain of 0.06%,thereby enabling its utility in accurately discerning the 5μm-height wrinkles in thin films and in monitoring human pulse *** ultra-high sensitivity is attributed to the formation of porous ferroelectret and the efficient load transfer efficiency of continuous lead zirconate titanate ***,when integrated with machine learning techniques,the sensor’s capability to recognize multi-signals enables it to differentiate between 10 types of fine textures with 100%*** structural design in piezoelectric devices enables a more comprehensive perception of mechanical stimuli,offering a novel perspective for enhancing recognition accuracy.

关键词： Flexible piezoelectric filaments Anisotropic Ultra-high sensitivity Structural health detection Texture recognition

Algorithm and experiments of six-dimensional force/torque dynamic measurements based on a Stewart platform

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Chinese Journal of Aeronautics 2016年第6期29卷 1840-1851页

作者： Wen Ke Du Fuzhou Zhang Xianzhi school of mechanical engineering and Automation Beihang University school of mechanical and aerospace engineering Kingston University

Stewart platform(SP) is a promising choice for large component alignment, and interactive force measurements are a novel and significant approach for high-precision assemblies. The designed position and orientation(P&O) adjusting platform, based on an SP for force/torquedriven(F/T-driven) alignment, can dynamically measure interactive forces. This paper presents an analytical algorithm of measuring six-dimensional F/T based on the screw theory for accurate determination of external forces during alignment. Dynamic gravity deviations were taken into consideration and a compensation model was developed. The P&O number was optimized as *** the specific appearance of repeated six-dimensional F/T measurements, an approximate cone shape was used for spatial precision analysis. The magnitudes and directions of measured F/Ts can be evaluated by a set of standards, in terms of accuracy and repeatability. Experiments were also performed using a known applied load, and the proposed analytical algorithm was able to accurately predict the F/T. A comparison between precision analysis experiments with or without assembly fixtures was performed. Experimental results show that the measurement accuracy varies under different P&O sets and higher loads lead to poorer accuracy of dynamic gravity compensation. In addition, the preferable operation range has been discussed for high-precision assemblies with smaller deviations.

关键词： Dynamic gravity compensation F/T-driven alignment Precision analysis P&O adjusting platform Six-dimensional F/T

In-line digital holography for dynamic metrology of MEMS(Invited Paper)

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Chinese Optics Letters 2009年第12期7卷 1117-1122页

作者： Vijay Raj Singh Anand Asundi school of mechanical and aerospace engineering Nanyang Technological University

In-line digital holography helps to relax the spatial resolution requirement on charge-coupled device sensors for digital recording of holograms and to utilize the full sensing area for image reconstruction which provides larger field of view and better imaging resolution. In this letter, a lensless in-line digital holographic microscopy is presented for dynamic metrology of micro-electro-mechanical system devices. The methodologies of interferometry and time-averaged in-line digital holography are presented for dynamic measurements, which are also useful for simultaneous suppression of in-line waves from real image wave. The experimental results are presented for dynamic thermal characterization of microheater and vibration analysis of cantilevers.

关键词： line MEMS