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VMMAO-YOLO:an ultra-lightweight and scale-aware detector for real-time defect detection of avionics thermistor wire solder joints

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Frontiers of mechanical Engineering 2024年第3期19卷 77-92页

作者： Xiaoqi YANG Xingyue LIU Qian WU Guojun WEN Shuang MEI Guanglan LIAO Tielin SHI School of mechanical Engineering and Electronic Information China University of GeosciencesWuhan 430074China State key laboratory of Digital Manufacturing equipment and Technology Huazhong University of Science and TechnologyWuhan 430074China

The quality of the exposed avionics solder joints has a significant impact on the stable operation of the inorbit ***,the previously reported inspection methods for multi-scale solder joint defects generally suffer low accuracy and slow detection ***,a novel real-time detector VMMAO-YOLO is demonstrated based on variable multi-scale concurrency and multi-depth aggregation network(VMMANet)backbone and“one-stop”global information gather-distribute(OS-GD)*** with infrared thermography technology,it can achieve fast and high-precision detection of both internal and external solder joint ***,VMMANet is designed for efficient multi-scale feature extraction,which mainly comprises variable multi-scale feature concurrency(VMC)and multi-depth feature aggregation-alignment(MAA)*** can extract multi-scale features via multiple fix-sized and deformable convolutions,while MAA can aggregate and align multi-depth features on the same order for feature *** allows the low-level features with more spatial details to be transmitted in depth-wise,enabling the deeper network to selectively utilize the preceding inference *** VMMANet replaces inefficient highdensity deep convolution by increasing the width of intermediate feature levels,leading to a salient decline in *** OS-GD is developed for efficacious feature extraction,aggregation and distribution,further enhancing the global information gather and deployment capability of the *** a self-made solder joint image data set,the VMMAOYOLO achieves a mean average precision mAP@0.5 of 91.6%,surpassing all the mainstream YOLO-series ***,the VMMAO-YOLO has a body size of merely 19.3 MB and a detection speed up to 119 frame per second,far superior to the prevalent YOLO-series detectors.

关键词： defect detection of solder joints VMMAO-YOLO ultra-lightweight and high-performance multiscale feature extraction VMC and MAA modules OS-GD

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A novel method for vibration signal transmission and attenuation analysis in complex planetary gearboxes

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Science China(Technological Sciences) 2024年第9期67卷 2939-2953页

作者： WEI ChaoHu CAO HongRui SHI JiangHai YANG Yang DU MingGang National and Local Joint Engineering Research Center of equipment Operation Safety and Intelligent monitoring Xi’an Jiaotong UniversityXi’an 710049China School of mechanical Engineering Xi’an Jiaotong UniversityXi’an 710049China China North Vehicle Research Institute Beijing 100072China

Planetary gearboxes play a crucial role in altering rotary speed and transmitting power in large machines like wind turbines and sophisticated vehicles. There are many nonlinear interfaces, such as splines, bearings, and gear pairs, in planetary gearboxes, and the resulting vibration signal transmission and attenuation mechanisms are still unknown. In this study, a novel method for quantitatively analyzing the transmission and attenuation of vibration signals is proposed. A multibody dynamic model of the planetary gearbox considering nonlinear gear meshing is presented and experimentally validated. To avoid the interference of foundation vibration on the transmission of the fault signal, the fault impact factor(FIF) is used to describe the intensity of the failure, which aligns well with the experimental signals. Based on the FIF, the vibration signal attenuation of nonlinear interfaces such as splines, bearings, and gear meshing interfaces is quantitatively evaluated. To clarify the transfer paths of fault vibration signals inside the gearbox, the transfer path area method(TPAM) based on FIF is proposed. According to the simulated results,the primary transfer paths of fault vibration signals within the gearbox have been identified, which is of great help in understanding the transmission and attenuation of vibration signals in planetary gearboxes.

关键词： planetary gearbox nonlinear interface fault mechanism vibration transmission vibration attenuation

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Novel modular quasi-zero stiffness vibration isolator with high linearity and integrated fluid damping

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Frontiers of mechanical Engineering 2024年第1期19卷 105-128页

作者： Wei ZHANG Jixing CHE Zhiwei HUANG Ruiqi GAO Wei JIANG Xuedong CHEN Jiulin WU State key laboratory of Intelligent Manufacturing equipment and Technology Huazhong University of Science and TechnologyWuhan 430074China School of mechanical Science and Engineering Huazhong University of Science and TechnologyWuhan 430074China

Passive vibration isolation systems have been widely applied due to their low power consumption and high ***,the design of vibration isolators is usually limited by the narrow space of installation,and the requirement of heavy loads needs the high supporting stiffness that leads to the narrow isolation frequency *** improve the vibration isolation performance of passive isolation systems for dynamic loaded equipment,a novel modular quasi-zero stiffness vibration isolator(MQZS-VI)with high linearity and integrated fluid damping is *** MQZS-VI can achieve high-performance vibration isolation under a constraint mounted space,which is realized by highly integrating a novel combined magnetic negative stiffness mechanism into a damping structure:The stator magnets are integrated into the cylinder block,and the moving magnets providing negative-stiffness force also function as the piston supplying damping force *** analytical model of the novel MQZS-VI is established and verified *** effects of geometric parameters on the characteristics of negative stiffness and damping are then elucidated in detail based on the analytical model,and the design procedure is proposed to provide guidelines for the performance optimization of the ***,static and dynamic experiments are conducted on the *** experimental results demonstrate the proposed analytical model can be effectively utilized in the optimal design of the MQZS-VI,and the optimized MQZS-VI broadened greatly the isolation frequency band and suppressed the resonance peak simultaneously,which presented a substantial potential for application in vibration isolation for dynamic loaded equipment.

关键词： vibration isolation quasi-zero stiffness damping magnetic spring integrated design

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Application of ultrasonic fatigue technology in very-high-cycle fatigue testing of aviation gas turbine engine blade materials:A review

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Science China(Technological Sciences) 2024年第5期67卷 1317-1363页

作者： ZHAO JiuCheng WAN Jie ZHANG ShiZhong YAN ChuLiang ZHAO HongWei key laboratory of CNC equipment Reliability Ministry of Education Jilin UniversityChangchun 130025China School of mechanical&Aerospace Engineering Jilin UniversityChangchun 130025China Chongqing Research Institute of Jilin University Chongqing401120China School of Aeronautic Science and Engineering Beihang UniversityBeijing 102206China

The need for very-high-cycle fatigue(VHCF)testing up to 1010cycles of aviation gas turbine engine blade materials under combined mechanical loads and complex environments has encouraged the development of VHCF testing instrumentation and *** article begins with a comprehensive review of the existing available techniques that enable VHCF *** advances in ultrasonic fatigue testing(UFT)techniques are highlighted,containing their new capabilities and methods for single load,multiaxial load,variable amplitude fatigue,and combined cycle *** techniques for conducting UFT in high-temperature,humid environments,and corrosive environments are *** developments in mechanical loading and environmental building techniques provide the possibility of laboratory construction for real service conditions of blade *** techniques that can be used for in situ monitoring of VHCF damage are *** issues in the UFT field are presented,and countermeasures are ***,the existing problems and future trends in the field are briefly described.

关键词： aviation gas turbine engine blade materials ultrasonic fatigue very-high-cycle fatigue high-temperature complex stress in situ testing

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Discrete element modeling and parameter calibration of safflower biomechanical properties

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International Journal of Agricultural and Biological Engineering 2024年第2期17卷 37-46页

作者： Zhenguo Zhang Chao Zeng Zhenyu Xing Peng Xu Quanfeng Guo Ruimeng Shi Yunze Wang College of mechanical and Electrical Engineering Xinjiang Agricultural UniversityUrumqi 830052China key laboratory of Xinjiang Intelligent Agricultural equipment Xinjiang Agricultural UniversityUrumqi 830052China

Understanding the biomechanical properties of safflowers is essential for appropriately designing harvesting machinery and optimizing the harvesting *** is a flexible crop that lacks a basis for relevant simulation parameters,which causes difficulties in designing harvesting *** this study,a calibration method for safflowers was ***,a discrete element model was established by measuring the intrinsic parameters of a safflower,such as its geometric parameters,density,Poisson’s ratio,and modulus of ***,the contact and bonding parameters were calibrated using a combination of physical and simulation *** the contact parameter tests,the Hertz-Mindlin(no-slip)model was implemented for the stacking angle tests conducted regarding the safflower filament.A regular two-level factorial design was used to determine the important factors and perform the steepest climb ***,the Box-Behnken design was adopted to obtain the optimal contact *** the bonding parameter tests,the Hertz-Mindlin model with bonding contact was applied for the safflower shear simulation tests;moreover,the optimum bonding parameters were obtained through the central composite design *** results demonstrated that the relative errors between the simulated and measured stacking angles and maximum shear were 3.19%and 5.29%,*** a result,the safflower simulation parameters were accurately calibrated,providing a reference for appropriately setting the simulation parameters and designing key mechanical components.

关键词： safflower DEM parameter calibration shear test biomechanical properties

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Nano-scale Reinforcements and Properties of Al-Si-Cu Alloy Processed by high-Pressure Torsion

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Journal of Wuhan University of Technology(Materials Science) 2024年第5期39卷 1253-1259页

作者： DONG Ying WU Siyuan HE Ziyang LIANG Chen CHENG Feng HE Zuwei QIAN Chenhao School of mechanical Engineering Jiangnan UniversityWuxi 214122China Jiangsu key laboratory of Advanced Food Manufacturing equipment and Technology Wuxi 214122China School of International Studies Renmin University of ChinaBeijing 100872China School of Engineering University of LiverpoolLiverpool L693GHUnited Kingdom

To improve the comprehensive mechanical properties of Al-Si-Cu alloy,it was treated by a high-pressure torsion process,and the effect of the deformation degree on the microstructure and properties of the Al-Si-Cu alloy was *** results show that the reinforcements(β-Si andθ-CuAl_(2)phases)of the Al-Si-Cu alloy are dispersed in theα-Al matrix phase with finer phase size after the *** processed samples exhibit grain sizes in the submicron or even nanometer range,which effectively improves the mechanical properties of the *** hardness and strength of the deformed alloy are both significantly raised to 268 HV and 390.04 MPa by 10 turns HPT process,and the fracture morphology shows that the material gradually transits from brittle to plastic before and after *** elements interdiffusion at the interface between the phases has also been effectively *** addition,it is found that the severe plastic deformation at room temperature induces a ternary eutectic reaction,resulting in the formation of ternary Al+Si+CuAl_(2)eutectic.

关键词： Al-Si-Cu alloy high-pressure torsion nano-scale reinforcements ternary eutectic

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Parameter calibration and experimental verification of discrete element simulation model for Protaetia brevitarsis larvae bioconversion mixture

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International Journal of Agricultural and Biological Engineering 2024年第4期17卷 35-44页

作者： Yuanze Li Jianhua Xie Jia Zhang Yong Yue Qinghe Meng Yakun Du Deying Ma College of mechanical and Electrical Engineering Xinjiang Agricultural UniversityUrumqi 830052China key laboratory of Xinjiang Intelligent Agricultural equipment Xinjiang Agricultural UniversityUrumqi 830052China

To improve the survival rate of larvae during material separation after biotransformation of existing residual film mixtures of Protaetia brevitarsis larvae,this paper adopts the method of combining physical test and EDEM simulation test,and selects Hertz Mindlin with JKR contact model to calibrate the discrete element simulation contact parameters of the Protaetia brevitarsis larvae and the frass ***,the cylinder lifting method was used to determine the actual repose angle of the mixture of larvae and *** collision recovery coefficients between larvae-frass and steel,static friction coefficient,kinetic friction coefficient and the collision recovery coefficient between larvae were measured through physical tests such as the inclined plane *** Plackett-Burman test was then used to screen out the factors that have a significant impact on the repose angle:Poisson’s ratio of frass,frass-frass rolling friction coefficient,frass JKR surface energy,frass-larvae JKR surface *** optimal value intervals of four significant factors were determined based on the steepest climb test,Based on the Box-Behnken response surface analysis test,the second-order regression model between the repose angle and four significant factors was determined,and variance and interaction effects were *** with the actual repose angle as the goal,the significant factors were optimized and the optimal parameter combination of the four significant factors was *** simulation test of material repose angle and screening was carried out with the optimal parameter combination,and compared with the physical *** was found that the maximum relative errors of the two tests were 1.48%and 3.79%respectively,indicating that the calibrated parameter values are true and reliable,It can provide a reference for the discrete element simulation of the transportation and separation of the Protaetia brevitarsis larvae-frass mixture.

关键词： Protaetia brevitarsis larvae-frass mixture repose angle parameter calibration discrete element model

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Design and parameters optimization of the curved sieve for an air suction jujube harvester

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International Journal of Agricultural and Biological Engineering 2024年第2期17卷 132-139页

作者： Shenghe Bai Yanwei Yuan Kang Niu Liming Zhou Bo Zhao Liguo Wei Lijing Liu Xuejun Zhang College of Engineering China Agricultural UniversityBeijing 100083China National key laboratory of Agricultural equipment Technology Chinese Academy of Agricultural Mechanization Sciences Group Co.Ltd.Beijing 100083China College of mechanical and Electrical Engineering Xinjiang Agricultural UniversityUrumqi 830052China

In order to improve the screening performance and cleaning effect of the jujube harvesting machinery cleaning device,a vibrating curved screen device was designed in this *** analyzing the structure mechanism of the curved sieve body,it was obtained that the arc-shaped mesh hole spacing S was 15-25 mm and the curved mesh hole curvature U was 90°-150°.By exploring the movement state and stress of jujube and impurities on the curved sieve body,it was determined that the horizontal spacing L of the curved layer sieve was 30 mm and the vertical spacing H was 45-65 *** the vertical spacing H of the curved layer sieve,the curvature U of the curved mesh hole,and the spacing S of the curved mesh hole as the experimental factors,considering the screening efficiencyαand the impurity contentβof the jujube as the response values,the three-factor three-level quadratic regression orthogonal experiment was designed,establishing the regression mathematical model of each factor and response value,and the multiple target optimization algorithm of Design-expert software was used to optimize various *** results showed that the influence factors on the screening efficiency were in the descending order as:the arc screen spacing,the vertical spacing of the curved layer screen,and the curved screen hole curvature;The significant factors affecting the impurity content of jujube were in the descending order as:the arc screen spacing,the curved screen hole curvature,and the vertical spacing of the curved layer *** experimental results were verified by the optimized combination of parameters:when the vertical spacing H of the curved layer screen was 65 mm,the curved screen hole curvature U was 110°,and the arc screen spacing S was 23 mm,the average screening efficiencyαin the test was 91.09%.The relative error between the experimental verification value and the theoretical optimization value was 1.36%,which was less than 5%.The impurity content of jujubeβin the test w

关键词： jujube harvesting cleaning device curved sieve sieve structure conveying pipe mathematical model

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Multi-Material magnetic field-assisted additive manufacturing system for flexible actuators with programmable magnetic arrangements

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Frontiers of mechanical Engineering 2024年第2期19卷 109-120页

作者： Yujie HUANG Haonan SUN Chengqian ZHANG Ruoxiang GAO Hongyao SHEN Peng ZHAO The State key laboratory of Fluid Power and Mechatronic Systems College of Mechanical EngineeringZhejiang UniversityHangzhou 310027China The key laboratory of 3D Printing Process and equipment of Zhejiang Province College of Mechanical EngineeringZhejiang UniversityHangzhou 310027China Center for X-Mechanics Department of Engineering MechanicsZhejiang UniversityHangzhou 310027China

Manufacturing flexible magnetic-driven actuators with complex structures and magnetic arrangements to achieve diverse functionalities is becoming a popular *** various manufacturing technologies,magnetic-assisted digital light processing(DLP)stands out because it enables precise manufacturing of macro-scale structures and micro-scale distributions with the assistance of an external magnetic *** research on manufacturing magnetic flexible actuators mostly employs single materials,which limits the magnetic driving performance to some *** on these characterizations,we propose a multi-material magnetic field-assisted DLP technology to produce flexible actuators with an accuracy of 200μ*** flexible actuators are printed using two materials with different mechanical and magnetic *** the interface connectivity of multi-material printing,the effect of interfaces on mechanical properties is also *** results indicate good chemical affinity between the two materials we *** overlap or connection length of the interface moderately improves the tensile strength of multi-material *** addition,we investigate the influence of the volume fraction of the magnetic part on *** and experimental results indicate that increasing the volume ratio(20%to 50%)of the magnetic structure can enhance the responsiveness of the actuator(more than 50%).Finally,we successfully manufacture two multi-material flexible actuators with specific magnetic arrangements:a multi-legged crawling robot and a flexible gripper capable of crawling and grasping *** results confirm that this method will pave the way for further research on the precise fabrication of magnetic flexible actuators with diverse functionalities.

关键词： multi-material magnetic field-assisted manufacturing digital light processing flexible actuators magnetic arrangement

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An M-VCUT level set-based data-driven model of microstructures and optimization of two-scale structures

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Frontiers of mechanical Engineering 2024年第4期19卷 73-86页

作者： Minjie SHAO Tielin SHI Qi XIA State key laboratory of Intelligent Manufacturing equipment and Technology Huazhong University of Science and TechnologyWuhan 430074China

The optimization of two-scale structures can adapt to the different needs of materials in various regions by reasonably arranging different microstructures at the macro scale,thereby considerably improving structural ***,a multiple variable cutting(M-VCUT)level set-based data-driven model of microstructures is presented,and a method based on this model is proposed for the optimal design of two-scale *** geometry of the microstructure is described using the M-VCUT level set method,and the effective mechanical properties of microstructures are computed by the homogenization ***,a database of microstructures containing their geometric and mechanical parameters is *** two sets of parameters are adopted as input and output datasets,and a mapping relationship between the two datasets is established to build the data-driven model of *** the optimization of two-scale structures,the data-driven model is used for macroscale finite element and sensitivity *** efficiency of the analysis and optimization of two-scale structures is improved because the computational costs of invoking such a data-driven model are much smaller than those of homogenization.

关键词： two-scale structure structural optimization M-VCUT level set homogenization radial basis function data-driven

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