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Three-dimensional parametric contact analysis of planetary roller screw mechanism and its application in grouping for selective assembly

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Frontiers of mechanical Engineering 2024年第1期19卷 53-72页

作者： Huilin HE Peitang WEI Huaiju LIU Xuesong DU Rui HU Genshen LIU Yajun WU State key laboratory of mechanical Transmission for Advanced equipment Chongqing UniversityChongqing 400044China Taiyuan Heavy Machinery Group Co. Ltd.Taiyuan 030024China

The planetary roller screw mechanism(PRSM)is a novel precision transmission mechanism that realizes the conversion between linear and rotary *** contact characteristics of helical surfaces directly determine PRSM’s performance in load-carrying capacity and transmission ***,studying the contact characteristics of PRSM forms the fundamental basis for enhancing its transmission *** this study,a three-dimensional parametric analysis method of contact characteristics is proposed based on the PRSM meshing principle and PyVista(a high-level API to the Visualization Toolkit).The proposed method considers the influence of machining errors among various thread *** effects of key machining errors on contact positions and axial clearance,as well as their sensitivities,are *** excellent solution accuracy,this method exhibits higher calculation efficiency and stronger robustness than the analytical and numerical meshing *** influence of nominal diameter and pitch errors of the screw,roller,and nut on the axial clearance follows a linear relationship,whereas flank angle errors have negligible effects on the axial *** corresponding influence coefficients for these three machining errors on the axial clearance are 0.623,0.341,and *** variations in contact positions caused by individual errors are *** angle errors and roller diameter errors result in linear displacements of the contact points,whereas pitch errors cause the contact points to move along the arc of the roller *** on the proposed threedimensional parametric contact characteristics analysis method,the Fuzzy C-Means clustering algorithm considering error sensitivity is utilized to establish a component grouping technique in the selective assembly of critical PRSM components,ensuring the rational and consistent clearances based on the given component’s machining *** study provides effective guidance for analyzing conta

关键词： planetary roller screw mechanism(PRSM) contact position axial clearance machining error grouping for selective assembly

Assessment of Dependent Performance Shaping Factors in SPAR-H Based on Pearson Correlation Coefficient

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Computer Modeling in Engineering & Sciences 2024年第2期138卷 1813-1826页

作者： Xiaoyan Su Shuwen Shang Zhihui Xu Hong Qian Xiaolei Pan School of Automation Engineering Shanghai University of Electric PowerShanghai 200090China State key laboratory of Nuclear Power Safety monitoring Technology and equipment Shenzhen518172China

With the improvement of equipment reliability,human factors have become the most uncertain part in the *** standardized Plant Analysis of Risk-Human Reliability Analysis(SPAR-H)method is a reliable method in the field of human reliability analysis(HRA)to evaluate human reliability and assess risk in large complex ***,the classical SPAR-H method does not consider the dependencies among performance shaping factors(PSFs),whichmay cause overestimation or underestimation of the risk of the actual *** address this issue,this paper proposes a new method to deal with the dependencies among PSFs in SPAR-H based on the Pearson correlation ***,the dependence between every two PSFs is measured by the Pearson correlation ***,the weights of the PSFs are obtained by considering the total dependence ***,PSFs’multipliers are modified based on the weights of corresponding PSFs,and then used in the calculating of human error probability(HEP).A case study is used to illustrate the procedure and effectiveness of the proposed method.

关键词： Reliability evaluation human reliability analysis SPAR-H performance shaping factors dependence pearson correlation analysis

Field-assisted machining of difficult-to-machine materials

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International Journal of Extreme Manufacturing 2024年第3期6卷 39-89页

作者： Jianguo Zhang Zhengding Zheng Kai Huang Chuangting Lin Weiqi Huang Xiao Chen Junfeng Xiao Jianfeng Xu State key laboratory of Intelligent Manufacturing equipment and Technology School of Mechanical Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074People’s Republic of China School of mechanical Engineering Hubei University of TechnologyWuhan 430068People’s Republic of China

Difficult-to-machine materials (DMMs) are extensively applied in critical fields such as aviation,semiconductor,biomedicine,and other key fields due to their excellent material ***,traditional machining technologies often struggle to achieve ultra-precision with DMMs resulting from poor surface quality and low processing *** recent years,field-assisted machining (FAM) technology has emerged as a new generation of machining technology based on innovative principles such as laser heating,tool vibration,magnetic magnetization,and plasma modification,providing a new solution for improving the machinability of *** technology not only addresses these limitations of traditional machining methods,but also has become a hot topic of research in the domain of ultra-precision machining of *** new methods and principles have been introduced and investigated one after another,yet few studies have presented a comprehensive analysis and *** fill this gap and understand the development trend of FAM,this study provides an important overview of FAM,covering different assisted machining methods,application effects,mechanism analysis,and equipment *** current deficiencies and future challenges of FAM are summarized to lay the foundation for the further development of multi-field hybrid assisted and intelligent FAM technologies.

关键词： field-assisted machining difficult-to-machine materials materials removal mechanism surface integrity

Continuous adaptive gaits manipulation for three-fingered robotic hands via bioinspired fingertip contact events

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Biomimetic Intelligence & Robotics 2024年第1期4卷 59-69页

作者： Xiaolong Ma Jianhua Zhang Binrui Wang Jincheng Huang Guanjun Bao College of mechanical and Electrical Engineering China Jiliang UniversityHangzhou 310018China School of mechanical Engineering University of Science and Technology BeijingBeijing 100083China College of mechanical Engineering Zhejiang University of TechnologyHangzhou 310023China key laboratory of Special Purpose equipment and Advanced Processing Technology Ministry of Education and Zhejiang ProvinceZhejiang University of TechnologyHangzhou 310023China

The remarkable skill of changing its grasp status and relocating its fingers to perform continuous in-hand manipulation is essential for a multifingered anthropomorphic hand.A commonly utilized method of manipulation involves a series of basic movements executed by a high-level ***,it remains unclear how these primitives evolve into sophisticated finger gaits during ***,we propose an adaptive finger gait-based manipulation method that offers real-time regulation by dynamically changing the primitive interval to ensure the force/moment balance of the *** manipulation relies on contact events that act as triggers for real-time online replanning of multifinger *** identify four basic motion primitives of finger gaits and create a heuristic finger gait that enables the continuous object rotation of a round *** experimental results verify the effectiveness of the proposed *** the constant breaking and reengaging of contact between the fingers and the object during manipulation,the robotic hand can reliably manipulate the object without *** when the object is subjected to interfering forces,the proposed method demonstrates robustness in managing *** work has great potential for application to the dexterous operation of anthropomorphic multifingered hands.

关键词： Adaptive switch Contact event Continuous manipulation Multifinger gait Primitive

Research on the mechanism of the two-dimensional ultrasonic surface burnishing process to enhance the wear resistance for aluminum alloy

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Friction 2024年第3期12卷 490-509页

作者： Zhen-Yu ZHOU Qiu-Yang ZHENG Yu LI Cong DING Guang-Jian PENG Zhong-Yu PIAO College of mechanical Engineering Zhejiang University of TechnologyHangzhou 310023China key laboratory of Special Purpose equipment and Advanced Processing Technology Ministry of Education and Zhejiang ProvinceZhejiang University of TechnologyHangzhou 310014China

The gradient nanostructure is machined on the aluminum(Al)alloy by the two-dimensional ultrasonic surface burnishing process(2D-USBP).The mechanism of why the gradient nanostructure enhances wear resistance is *** mechanical properties and microstructure characterization for the gradient nanostructure are performed by operating a nanoindenter,transmission electron microscopy(TEM),and electron backscattered diffraction(EBSD).Dry wear tests are performed on the samples before and after machining to evaluate the wear resistance and *** effect of the gradient nanostructure on the wear resistance is explored by developing the crystal plasticity(CP)finite element and molecular dynamics(MD)*** characterization results show that the 2D-USBP sample prepared a gradient structure of~600μm thick on the aluminum surface,increasing the surface hardness from 1.13 to 1.71 GPa and reducing the elastic modulus from 78.84 to 70.14 *** optimization of the surface microstructure and the increase of the mechanical properties effectively enhance the wear resistance of the sample,with 41.20%,39.07%,and 54.58% of the wear scar areas for the 2D-USBP treated samples to the original samples under 5,10,and 15 N loads,*** gradient nanostructure hinders the slip of dislocations inside the sample during the wear process and reduces the size and scope of plastic deformation;meanwhile,the resistance to deformation,adhesion,and crack initiation and propagation of the sample surface is improved,resulting in enhanced wear resistance.

关键词： structural superlubricity lattice registry elastic deformation strained solitons crystal plasticity molecular dynamics simulations

Thermal fatigue and wear of compacted graphite iron brake discs with various thermomechanical properties

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China Foundry 2024年第3期21卷 248-256页

作者： Gui-quan Wang Zhuo Xu Zhong-li Liu Xiang Chen Yan-xiang Li School of Nuclear equipment and Nuclear Engineering Yantai UniversityYantai 264005ShandongChina School of Materials Science and Engineering Tsinghua UniversityBeijing 100084China key laboratory for Advanced Materials Processing Technology Ministry of EducationBeijing 100084China

The increase in payload capacity of trucks has heightened the demand for cost-effective yet high performance brake *** this work,the thermal fatigue and wear of compacted graphite iron brake discs were investigated,aiming to provide an experimental foundation for achieving a balance between their thermal and mechanical *** graphite iron brake discs with different tensile strengths,macrohardnesses,specific heat capacities and thermal diffusion coefficients were produced by changing the proportion and strength of *** peak temperature,pressure load and friction coefficient of compacted graphite iron brake discs were analyzed through inertia friction *** morphology of thermal cracks and 3D profiles of the worn surfaces were also *** is found that the thermal fatigue of compacted graphite iron discs is determined by their thermal properties.A compacted graphite iron with the highest specific heat capacity and thermal diffusion coefficient exhibits optimal thermal fatigue *** of the matrix at low temperatures significantly weakens the function of alloy strengthening in hindering the propagation of thermal *** the reduced hardness,increasing the ferrite proportion can mitigate wear loss resulting from low disc temperatures and the absence of abrasive wear.

关键词： compacted graphite iron brake disc thermomechanical properties thermal fatigue wear

Influence of layer thickness on formation quality,microstructure,mechanical properties,and corrosion resistance of WE43 magnesium alloy fabricated by laser powder bed fusion

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Journal of Magnesium and Alloys 2024年第4期12卷 1367-1385页

作者： Bangzhao Yin Jinge Liu Bo Peng Mengran Zhou Bingchuan Liu Xiaolin Ma Caimei Wang Peng Wen Yun Tian Yufeng Zheng State key laboratory of Tribology in Advanced equipment Beijing100084China Department of mechanical Engineering Tsinghua UniversityBeijing 100084China Institute for Precision Medicine Tsinghua UniversityBeijing102218China Department of Orthopaedics Peking University Third HospitalBeijing 100191China beijing AKEC Medical Co. Ltd.Beijing 102200China School of Materials Science and Engineering Peking UniversityBeijing 100871China Engineering Research Center of Bone and Joint Precision Medicine Ministry of EducationBeijing 100191China

Laser powder bed fusion(L-PBF)of Mg alloys has provided tremendous opportunities for customized production of aeronautical and medical *** thickness(LT)is of great significance to the L-PBF process but has not been studied for Mg *** this study,WE43 Mg alloy bulk cubes,porous scaffolds,and thin walls with layer thicknesses of 10,20,30,and 40μm were *** required laser energy input increased with increasing layer thickness and was different for the bulk cubes and porous *** tended to occur at the connection joints in porous scaffolds for LT40 and could be eliminated by reducing the laser energy *** thin wall parts,a large overhang angle or a small wall thickness resulted in porosity when a large layer thicknesses was used,and the porosity disappeared by reducing the layer thickness or laser energy input.A deeper keyhole penetration was found in all occasions with porosity,explaining the influence of layer thickness,geometrical structure,and laser energy input on the *** the samples achieved a high fusion quality with a relative density of over 99.5%using the optimized laser energy *** increased layer thickness resulted to more precipitation phases,finer grain sizes and decreased grain *** the similar high fusion quality,the tensile strength and elongation of bulk samples were significantly improved from 257 MPa and 1.41%with the 10μm layer to 287 MPa and 15.12%with the 40μm layer,in accordance with the microstructural *** effect of layer thickness on the compressive properties of porous scaffolds was ***,the corrosion rate of bulk samples accelerated with increasing the layer thickness,mainly attributed to the increased number of precipitation phases.

关键词： Magnesium alloy WE43 Laser powder bed fusion Layer thickness Process optimization

Experimental study and simulation on the creep characteristics of machineharvested seed cotton

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International Journal of Agricultural and Biological Engineering 2024年第1期17卷 241-250页

作者： Ximei Wei Hongwen Zhang Jun Wang Shufeng Li Lei Wang Xintian Du College of mechanical and Electrical Engineering Shihezi UniversityShihezi 832003XinjiangChina key laboratory of Northwest Agricultural equipment Ministry of AgricultureShihezi 832003XinjiangChina

In view of the unclear understanding of the basic scientific problems such as the rheological mechanism of seed cotton,especially the lack of research on the creep characteristics of seed cotton,the machine-harvested seed cotton in the Xinjiang region was taken as the research object to find out the compression creep *** universal material testing machine was used to carry out a one-factor creep test,taking moisture content,feed quality,compression times,and trash content as test factors and instantaneous elastic modulus,hysteretic elastic modulus,viscosity coefficient,and delay time as test *** ANOVA and correlation were analyzed by SPSS,and the creep process of the seed cotton was simulated by *** show that moisture content significantly affects the instantaneous elastic modulus,hysteretic elastic modulus,and viscosity coefficient(p<0.01).In addition,each value of which decreases with the increase in moisture *** quality significantly affects the hysteretic elastic modulus and viscosity coefficient(p<0.05).Moreover,the hysteretic elastic modulus and viscosity coefficient increase with the increase in feed *** compression times significantly influence the instantaneous elastic modulus,hysteretic elastic modulus,and viscosity coefficient(p<0.01),each value of which increases with the increase of compression ***,the trash content significantly influenced the hysteretic elastic modulus and viscosity coefficient(p<0.05).The absolute error between the simulated and experimental values ek is within−0.011-0.030 mm,and the relative errorφk is less than 7%.The experimental results can provide theoretical and data support for the study of rheological characteristics of machine-harvested seed cotton,the design of seed cotton packing devices,and the molding quality of cotton bale(mold).

关键词： creep characteristics machine-harvested seed cotton analysis of ANOVA one-factor tests ADAMS

Research on intelligent search-and-secure technology in accelerator hazardous areas based on machine vision

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Nuclear Science and Techniques 2024年第4期35卷 96-107页

作者： Ying-Lin Ma Yao Wang Hong-Mei Shi Hui-Jie Zhang School of Traffic and Transportation Beijing Jiaotong UniversityBeijing 100044China School of mechanical Electronic and Control EngineeringBeijing Jiaotong UniversityBeijing 100044China Institute of high Energy Physics Chinese Academy of SciencesBeijing 100049China

Prompt radiation emitted during accelerator operation poses a significant health risk,necessitating a thorough search and securing of hazardous areas prior to ***,manual sweep methods are ***,the limitations of manual sweeps have become increasingly evident with the implementation of large-scale *** leveraging advancements in machine vision technology,the automatic identification of stranded personnel in controlled areas through camera imagery presents a viable solution for efficient search and *** the criticality of personal safety for stranded individuals,search and security processes must be sufficiently *** ensure comprehensive coverage,180°camera groups were strategically positioned on both sides of the accelerator tunnel to eliminate blind spots within the monitoring *** YOLOV8 network model was modified to enable the detection of small targets,such as hands and feet,as well as larger targets formed by individuals near the ***,the system incorporates a pedestrian recognition model that detects human body parts,and an information fusion strategy is used to integrate the detected head,hands,and feet with the identified pedestrians as a cohesive *** strategy enhanced the capability of the model to identify pedestrians obstructed by equipment,resulting in a notable improvement in the recall ***,recall rates of 0.915 and 0.82were obtained for Datasets 1 and 2,*** there was a slight decrease in accuracy,it aligned with the intended purpose of the search-and-secure software *** tests conducted within an accelerator tunnel demonstrated the effectiveness of this approach in achieving reliable recognition outcomes.

关键词： Search and secure Machine vision Camera Human body parts recognition Particle accelerator Hazardous area