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Analysis of the dynamic hysteresis characteristic of finger seal
LEI Yanni, CHEN Guoding
《机械工程前沿(英文)》 2007年 第2卷 第1期 页码 32-36 doi: 10.1007/s11465-007-0005-y
关键词: FS necessary hysteresis characteristic optimization spring
Flow characteristic and wastewater treatment performance of a pilot-scale airlift oxidation ditch
Hongtao PANG, Hanchang SHI, Huiming SHI,
《环境科学与工程前沿(英文)》 2009年 第3卷 第4期 页码 470-476 doi: 10.1007/s11783-009-0143-z
关键词: airlift oxidation ditch flow characteristic wastewater treatment
Research on applications of piezoelectric materials in smart structures
Jinhao QIU, Hongli JI
《机械工程前沿(英文)》 2011年 第6卷 第1期 页码 99-117 doi: 10.1007/s11465-011-0212-4
Piezoelectric materials have become the most attractive functional materials for sensors and actuators in smart structures because they can directly convert mechanical energy to electrical energy and vise versa. They have excellent electromechanical coupling characteristics and excellent frequency response. In this article, some research activities on the applications of piezoelectric materials in smart structures, including semi-active vibration control based on synchronized switch damping using negative capacitance, energy harvesting using new electronic interfaces, structural health monitoring based on a new type of piezoelectric fibers with metal core, and active hysteresis control based on new modified Prandtl-Ishlinskii model at the Aeronautical Science Key Laboratory for Smart Materials and Structures, Nanjing University of Aeronautics and Astronautics are introduced.
关键词: piezoelectric materials vibration control energy harvesting structural health monitoring piezoelectric hysteresis
Weak characteristic information extraction from early fault of wind turbine generator gearbox
Xiaoli XU, Xiuli LIU
《机械工程前沿(英文)》 2017年 第12卷 第3期 页码 357-366 doi: 10.1007/s11465-017-0423-4
Given the weak early degradation characteristic information during early fault evolution in gearbox of wind turbine generator, traditional singular value decomposition (SVD)-based denoising may result in loss of useful information. A weak characteristic information extraction based on µ-SVD and local mean decomposition (LMD) is developed to address this problem. The basic principle of the method is as follows: Determine the denoising order based on cumulative contribution rate, perform signal reconstruction, extract and subject the noisy part of signal to LMD and µ-SVD denoising, and obtain denoised signal through superposition. Experimental results show that this method can significantly weaken signal noise, effectively extract the weak characteristic information of early fault, and facilitate the early fault warning and dynamic predictive maintenance.
关键词: wind turbine generator gearbox µ-singular value decomposition local mean decomposition weak characteristic information extraction early fault warning
Dynamic characteristics of a magnetorheological pin joint for civil structures
Yancheng LI,Jianchun LI
《机械工程前沿(英文)》 2014年 第9卷 第1期 页码 15-33 doi: 10.1007/s11465-014-0283-0
Magnetorheological (MR) pin joint is a novel device in which its joint moment resistance can be controlled in real-time by altering the applied magnetic field. The smart pin joint is intended to be used as a controllable connector between the columns and beams of a civil structure to instantaneously shift the structural natural frequencies in order to avoid resonance and therefore to reduce unwanted vibrations and hence prevent structural damage. As an intrinsically nonlinear device, modelling of this MR fluid based device is a challenging task and makes the design of a suitable control algorithm a cumbersome situation. Aimed at its application in civil structure, the main purpose of this paper is to test and characterise the hysteretic behaviour of MR pin joint. A test scheme is designed to obtain the dynamic performance of MR pin joint in the dominant earthquake frequency range. Some unique phenomena different from those of MR damper are observed through the experimental testing. A computationally-efficient model is proposed by introducing a hyperbolic element to accurately reproduce its dynamic behaviour and to further facilitate the design of a suitable control algorithm. Comprehensive investigations on the model accuracy and dependences of the proposed model on loading condition (frequency and amplitude) and input current level are reported in the last section of this paper.
关键词: Magnetorheological pin joint hyperbolic hysteresis model experimental testing frequency dependence
Fractal characteristic evaluation and interpolation reconstruction for surface topography of drilled
《机械工程前沿(英文)》 2021年 第16卷 第4期 页码 840-854 doi: 10.1007/s11465-021-0643-5
关键词: surface topography fractal evaluation fractal interpolation reconstruction composite
Operating characteristic analysis on the ultra-thin low temperature floor-heating system
Hualing ZHANG, Xiaopeng SONG
《结构与土木工程前沿(英文)》 2013年 第7卷 第2期 页码 127-132 doi: 10.1007/s11709-013-0200-3
关键词: ultra-thin floor heating panel the preheating time thermal comfort energy saving
《机械工程前沿(英文)》 2023年 第18卷 第2期 doi: 10.1007/s11465-022-0735-x
关键词: electromechanical-hydraulic hybrid actuator (EMHA) integration transmission mechanisms power assistance energy efficiency working characteristics
Mesh relationship modeling and dynamic characteristic analysis of external spur gears with gear wear
《机械工程前沿(英文)》 2022年 第17卷 第1期 页码 9-9 doi: 10.1007/s11465-021-0665-z
关键词: gear wear mesh relationship mesh stiffness transmission error vibration characteristics
Macro-architectured cellular materials: Properties, characteristic modes, and prediction methods
Zheng-Dong MA
《机械工程前沿(英文)》 2018年 第13卷 第3期 页码 442-459 doi: 10.1007/s11465-018-0488-8
Macro-architectured cellular (MAC) material is defined as a class of engineered materials having configurable cells of relatively large (i.e., visible) size that can be architecturally designed to achieve various desired material properties. Two types of novel MAC materials, negative Poisson’s ratio material and biomimetic tendon reinforced material, were introduced in this study. To estimate the effective material properties for structural analyses and to optimally design such materials, a set of suitable homogenization methods was developed that provided an effective means for the multiscale modeling of MAC materials. First, a strain-based homogenization method was developed using an approach that separated the strain field into a homogenized strain field and a strain variation field in the local cellular domain superposed on the homogenized strain field. The principle of virtual displacements for the relationship between the strain variation field and the homogenized strain field was then used to condense the strain variation field onto the homogenized strain field. The new method was then extended to a stress-based homogenization process based on the principle of virtual forces and further applied to address the discrete systems represented by the beam or frame structures of the aforementioned MAC materials. The characteristic modes and the stress recovery process used to predict the stress distribution inside the cellular domain and thus determine the material strengths and failures at the local level are also discussed.
关键词: architectured material cellular materials multi-scale modeling homogenization method effective material properties computational method
Gas dynamic characteristic of displacer in Stirling cryocoolers
LIU Xinguang, LIU Dongyu, WANG Yong, WU Yinong
《能源前沿(英文)》 2008年 第2卷 第4期 页码 499-503 doi: 10.1007/s11708-008-0090-6
张福学
《中国工程科学》 2002年 第4卷 第8期 页码 50-53
根据自然对流气体具有摆的特性,从而提出气体摆新概念。分析了密闭腔中自然对流气体的浮升力,给出浮升力与温度变化的关系式。试验结果表明,与固体摆、液体摆一样,利用气体摆原理亦能检测加速度和倾角。
孟心斋,杨建玺,孟昭焱
《中国工程科学》 2002年 第4卷 第5期 页码 63-66
文章分析了液体静压支承传统的静态性能表达式存在的严重缺陷及其产生原因,提出了新的静态性能表达式。这种新的静态性能表达式精确地表达了外加载荷与轴承间隙之间的非线性关系,真实地反映了支承的静态性能。新的静态性能通用表达式可表达各种传统节流器与新型可变节流器节流时支承的主要静态性能,很有应用价值。新的静态性能表达式只有一个变量即外加载荷与油垫推力比,故可在支承节流与尺寸参数未确定之前知道支承的主要静态性能,它有利于事先选择与确定支承在应用时的主要性能,为正确应用液体静压支承提供了可靠的技术基础。
Evaluation of site response characteristic using nonlinear method (Case study: Babol, Iran)
Asskar Janalizadeh CHOOBBASTI, Sadegh REZAEI, Farzad FARROKHZAD, Pedram Haidarzaeh AZAR
《结构与土木工程前沿(英文)》 2014年 第8卷 第1期 页码 69-82 doi: 10.1007/s11709-014-0231-4
关键词: fully nonlinear method site effect dynamic analysis response spectra
Electromagnetic modeling and control of switched reluctance motor using finite elements
Ali ARIF,Abderrazak GUETTAF,Ahmed Chaouki MEGHERBI,Said BENRAMACHE,Fateh BENC HABANE
《能源前沿(英文)》 2014年 第8卷 第3期 页码 355-363 doi: 10.1007/s11708-014-0319-5
关键词: switched reluctance motor (SRM) hysteresis control finite element analysis
标题 作者 时间 类型 操作
Flow characteristic and wastewater treatment performance of a pilot-scale airlift oxidation ditch
Hongtao PANG, Hanchang SHI, Huiming SHI,
期刊论文
Weak characteristic information extraction from early fault of wind turbine generator gearbox
Xiaoli XU, Xiuli LIU
期刊论文
Dynamic characteristics of a magnetorheological pin joint for civil structures
Yancheng LI,Jianchun LI
期刊论文
Fractal characteristic evaluation and interpolation reconstruction for surface topography of drilled
期刊论文
Operating characteristic analysis on the ultra-thin low temperature floor-heating system
Hualing ZHANG, Xiaopeng SONG
期刊论文
Design and characteristic research of a novel electromechanical-hydraulic hybrid actuator with two transmission
期刊论文
Mesh relationship modeling and dynamic characteristic analysis of external spur gears with gear wear
期刊论文
Macro-architectured cellular materials: Properties, characteristic modes, and prediction methods
Zheng-Dong MA
期刊论文
Gas dynamic characteristic of displacer in Stirling cryocoolers
LIU Xinguang, LIU Dongyu, WANG Yong, WU Yinong
期刊论文
Evaluation of site response characteristic using nonlinear method (Case study: Babol, Iran)
Asskar Janalizadeh CHOOBBASTI, Sadegh REZAEI, Farzad FARROKHZAD, Pedram Haidarzaeh AZAR
期刊论文