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A deterministic FE contact analysis of 3D rough surfaces with textures and comparison with classic statistical contact models

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Science China(Technological Sciences) 2021年第2期64卷 297-316页

作者： ZHANG Rui MENG XiangHui LYU BuGao SUN Kai School of Mechanical Engineering Shanghai Jiao Tong UniversityShanghai 200240China AECC Commercial aircraft Engine company limited Shanghai 200241China

Accurate contact calculations of real rough surfaces are fundamental but complicated. The model-based methods are convenient and straightforward. But these methods ignore some factors and may lead to less accurate results. This is especially true when considering multi-scale topographic features of engineering rough surfaces. Based on artificially generated rough surfaces, the deterministic contact analysis of two 3D rough surfaces is conducted by the finite element method(FEM). The calculations show that when the separation between surfaces reduces, results of classic model-based methods are quite different from those of this study, especially when the roughness distribution and textures are considered. As friction pairs are working under increasing harsh conditions, the accurate contact calculation in this paper will be of great significance.

关键词： deterministic contact analysis multi-scale topography finite element method(FEM) engineering rough surfaces

Deformation mechanism and dynamic precipitation in a Mg-7Al-2Sn alloy processed by surface mechanical attrition treatment

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Journal of Materials Science & Technology 2019年第7期35卷 1473-1478页

作者： Xiaoying Shi Yangxin Li Xiaoqin Zeng Yong Liu Bin Chen Jian Lu Dejiang Li National Engineering Research Center of Light Alloy Net Forming and State Key Laboratory of Metal Matrix Composite Shanghai Jiao Tong UniversityShanghai200240China Commercial aircraft Engine company limited Aero Engine Corporation of ChinaShanghai200241China Key Laboratory of Near Net Forming of Jiangxi Province Nanchang UniversityNanchang330031China School of Materials Science and Engineering Shanghai Jiao Tong UniversityShanghai200240 Department of Mechanical and Biomedical Engineering City University of Hong KongKow-loonHong Kong999077China

The effect of second phases on the deformation mechanism of as-cast, solution-treated and aged Mg-7Al-2Sn (AT72) alloys during surface mechanical attrition treatment (SMAT) was investigated. Twinning was suppressed in the alloys containing second phases, which can provide nonuniform microstructures and phase boundaries as dislocation sources. Dynamic precipitation in AT72 alloys was studied during SMAT deformation as ***2Sn particles can dynamically precipitate on the surface of all AT72 alloys during SMAT process. The quantity of Mg2Sn particles in the as-cast alloy, which is determined by the initial quantity of second phases, is larger than that of T4 and T6 alloys after the SMAT process.

关键词： Magnesium alloys Surface mechanical attrition treatment Deformation mechanism Dynamic precipitation

Analysis of the buoyancy-induced heat transferin a rotating cavity

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航空动力学报 2012年第3期27卷 566-571页

作者： Tian, Shu-Qing Xue, Hang Gao, Chao Li, Ying Technology Department Aviation Industry Corporation of China Commercial Aircraft Engine Company Limited Shanghai 200241 China Institute of Steam and Gas Turbines Rheinisch-Westfaelische Technische Aachen University Germany Civil aircraft Marketing and Sales Aviation Industry Corporation of China International Holding Corporation Beijing 100101 China School of Jet Propulsion Beijing University of Aeronautics and Astronautics Beijing 100191 China Hekou Oil Production Plant of Shengli Oilfield Sinopec Group Shandong Dongying 257200 China

In order to get a better knowledge of the heat transfer in compressor cavities of aero-engines,the simplified rotating cavity with two-plane discs,a shaft and a cylindrical rim has been investigated numerically and compared with the available *** numerical results in agreement with the available experiments show large-scale *** disk local Nusselt numbers show mainly radial rising distributions for the heated disks with radial rising temperature *** the present work,at the Reynolds number of 20 000,the disk local Nusselt numbers are the correlations of the local Grashof number to the power of 1.89-2.6,and the value of the power is increased as the rotational Reynolds number goes *** the rotational Reynolds number of 800 000,the local Nusselt numbers are the correlations of the local Grashof number to the power of 0.68-2.6,and the value of the power is decreased as Reynolds number goes *** area-averaged disk Nusselt number is the correlation of the Reynolds number to the power of 0.479 and the rotational Grashof number to the power of 0.12.

关键词： buoyancy force Coriolis force rotating cavity heat transfer turbine

Trajectory optimisation in electrical discharge machining of three-dimensional curved and twisted channels

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Chinese Journal of Aeronautics 2022年第4期35卷 473-484页

作者： Jianshe ZHAO Yicong QIU Jian YUAN Chao LIU College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China Laboratory of Integrated Electrical Processing Nanjing HANGPU Machinery Technology Company LimitedNanjing 210000China Military Representative Bureau of the Air Force Equipment Department in shanghai and Military Representative Office in Zhuzhou Region Zhuzhou 412002China AECC South Industry company limited Zhuzhou 412002China

Numerical control electrical discharge machining(NC EDM) is one of the most widely used machining technologies for manufacturing a closed blisk flow path, particularly for three-dimensional(3D) curved and twisted flow channels. In this process, tool electrode design and machining trajectory planning are the key factors affecting machining accessibility and efficiency. Herein, to reduce the difficulty in designing the electrode and its motion path in the closed curved and twisted channels, a heuristic search hybrid optimisation strategy based on channel grids is adopted to realise the initial electrode trajectory design search and optimised size reduction. By transferring the trajectory optimisation constraints from the complex free-form surface to numbered grids, the search is found to be more orderly and accurate. The two trajectory indicators, namely argument angle and minimum distance, are analysed separately for the optimised results of the adaptive learning particle swarm optimisation algorithm, demonstrating that they can meet the actual processing *** results of NC EDM indicate that the motion path generated by this design method can meet the machining requirements of 3D curved and twisted flow channels.

关键词： Blisk Electrical discharge machining(EDM) Electrode Objective functions Trajectory generation

Smoothed particle hydrodynamics based numerical study of hydroplaning considering permeability characteristics of runway surface

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Frontiers of Structural and Civil Engineering 2024年第3期18卷 319-333页

作者： Yang YANG Xingyi ZHU Denis JELAGIN Alvaro GUARIN Key Laboratory of Road and Traffic Engineering of Ministry of Education Tongji UniversityShanghai 200092China Auto Engineering Research Institute BYD Auto Industry Company LimitedShenzhen 518118China Department of Civil and Architectural Engineering KTH Royal Institute of TechnologyStockholm 10044Sweden

The presence of water films on a runway surface presents a risk to the landing of *** tire of the aircraft is separated from the runway due to a hydrodynamic force exerted through the water film,a phenomenon called *** a lot of numerical investigations into hydroplaning have been conducted,only a few have considered the impact of the runway ***,computational problems,such as excessive distortion and computing efficiency decay,may arise with such numerical models when dealing with the thin water *** paper presents a numerical model comprising of the tire,water film,and the interaction with the runway,applying a mathematical model using the smoothed particle hydrodynamics and finite element(SPH-FE)*** material properties and geometric features of the tire model were included in the model framework and water film thicknesses from 0.75 mm to 7.5 mm were used in the numerical ***,this work investigated the impacts of both surface texture and the runway *** interaction between tire rubber and the rough runway was analyzed in terms of frictional force between the two *** SPH-FE model was validated with an empirical equation proposed by the National Aeronautics and Space Administration(NASA).Then the computational efficiency of the model was compared with the traditional coupled Eulerian-Lagrangian(CEL)*** on the SPH-FE model,four types of the runway(Flat,SMA-13,AC-13,and OGFC-13)were *** simulation of the asphalt runway shows that the SMA-13,AC-13,and OGFC-13 do not present a hydroplaning risk when the runway permeability coefficient exceeds 6%.

关键词： SPH-FE approach hydroplaning numerical simulation surface texture runway surface reconstruction

A Unified Architecture Model of Web Applications

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Advances in manufacturing 2002年第3期6卷 221-227页

作者：李景峰李琰陈平 Software Engineering Institute of Xidian University Xi’an China Research and Development Division Shanghai Bell Company Limited Shanghai China

With the increasing popularity, scale and complexity of web applications, design and development of web applications are becoming more and more difficult. However, the current state of their design and development is characterized by anarchy and ad hoc methodologies. One of the causes of this chaotic situation is that different researchers and designers have different understanding of web applications. In this paper, based on an explicit understanding of web applications, we present a unified architecture model of web applications, the four view model, which addresses the analysis and design issues of web applications from four perspectives, namely, logical view, data view, navigation view and presentation view, each addressing a specific set of concerns of web applications. The purpose of the model is to provide a clear picture of web applications to alleviate the chaotic situation and facilitate its analysis, design and implementation.

关键词： web application architecture model four view model view.

Hybrid Model of Multi-agent and DEDS for Steelmaking-Continuous Casting-Hot Rolling manufacturing Process Simulation

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Hybrid Model of Multi-agent and DEDS for Steelmaking-Continu...

CableSAM: an efficient automatic segmentation method for aircraft cabin cables

第26届中国控制与决策会议

作者： Duan Xu Chao Lu Wei Zhou Shixin Liu shanghai Baosight Software limited company College of Information Science & Engineering Northeastern University

ISBN: (纸本)9781479937097

The planning and scheduling problems of steelmaking- continuous casting- hot rolling（SCH）manufacturing process are hard to solve with traditional optimization *** for the limitation of human ability,manual plans and schedules can not guarantee quality,robustness and material balance between *** the rapid development of computer simulation theories and virtual reality technologies,computer simulation has been becoming an effective method for solving complex problems and evaluating complex *** simulation system of SCH manufacturing process can be used for evaluating quality and robustness of plans and schedules in order to find the weakness and bottleneck in the manufacturing process before they are *** this paper,a hybrid simulation model of multi-agent and discrete event dynamic system（DEDS） for SCH manufacturing process is *** general simulation procedure and computer simulation system framework based on the hybrid model are *** structure,attributes,functions,interfaces,communication protocols and negotiation mechanism of different types of agent are *** on the hybrid simulation model,a computer simulation system for SCH manufacturing process is developed in C++ *** results of simulation experiments using practical production data of a Chinese steel plant show that the simulation model and the simulation system are valid and efficient.

关键词： Steelmaking-continuous casting-hot rolling simulation hybrid model multi-agents DEDS

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Optoelectronics Letters 2024年

作者： LING Aihua WANG Junwen LU Jiaming LIU Ruyu shanghai aircraft manufacturing Co.，Ltd School of Computer Science and Engineering， Tianjin University of Technology School of Information Science and Technology， Hangzhou Normal University

Cabin cables， as critical components of an aircraft’s electrical system， significantly impact the operational efficiency and safety of the aircraft. The existing cable segmentation methods in civil aviation cabins are limited， especially in automation， being heavily dependent on large amounts of data and resources， lacking the flexibility to adapt to different scenarios. To address these challenges， this paper introduces a novel image segmentation model， CableSAM， specifically designed for automated segmentation of cabin cables. CableSAM improves segmentation efficiency and accuracy using knowledge distillation and employs a context ensemble strategy. It accurately segments cables in various scenarios with minimal input prompts. Comparative experiments on three cable datasets demonstrate that CableSAM surpasses other advanced cable segmentation methods in performance.

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Friction Behavior of Laser Beam Texture Sheets and Shot Blast Sheets

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Advances in manufacturing 2000年第1期4卷 68-71页

作者： Luo-ping Xu Xu-bang Qin Hong-sheng Huang Wen-hua Bao School of Material Science and Engineering Shanghai University Shanghai China shanghai Volkswagen Automotive company limited Shanghai China

The friction behaviors of steel sheets at the corners of die and punch, under different conditions of surface textures (laser beam texture, shot blast texture), steel sheet rolling directions and lubricants, are studied by both SEM micro surface observations and friction coefficients measurement. The results show the friction coefficient at the corner of die is smaller than that at the corner of punch during stamping. The friction coefficient along rolling direction is lower than that along transverse direction, especially at the corner of punch. Differential initial surface texture has different sensitivity of friction coefficient to the lubricants. The sheet surface with laser beam texture (LBT) has shown a stronger adaptation to various lubricants than that with shot blast texture (SBT). After stamping, the surface with laser beam texture is still clear, the shot blast texture is indistinct.

关键词： surface texture laser beam texture shot blast texture friction coefficient