检索范围:
排序: 展示方式:
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
ZHANG Shiliang, ZHOU Jie, CHEN Xiaohu
《能源前沿(英文)》 2008年 第2卷 第2期 页码 183-186 doi: 10.1007/s11708-008-0025-2
Dependence of error sensitivity of frequency on bias voltage in force-balanced micro accelerometer
Lili CHEN, Wu ZHOU
《机械工程前沿(英文)》 2013年 第8卷 第2期 页码 146-149 doi: 10.1007/s11465-013-0260-z
To predict more precisely the frequency of force-balanced micro accelerometer with different bias voltages, the effects of bias voltages on error sensitivity of frequency is studied. The resonance frequency of accelerometer under closed loop control is derived according to its operation principle, and its error sensitivity is derived and analyzed under over etching structure according to the characteristics of Deep Reaction Ion Etching (DRIE). Based on the theoretical results, micro accelerometer is fabricated and tested to study the influences of AC bias voltage and DC bias voltage on sensitivity, respectively. Experimental results indicate that the relative errors between test data and theory data are less than 7%, and the fluctuating value of error sensitivity under the range of voltage adjustment is less than 0.01 μm . It is concluded that the error sensitivity with designed parameters of structure, circuit and process error can be used to predict the frequency of accelerometer with no need to consider the influence of bias voltage.
关键词: Micro-Electro-Mechanical Systems (MEMS) micro accelerometer force-balanced micro accelerometer frequency error sensitivity
Fundamental frequency and testing mode of complicated elastic clamped-plate vibration
QI Hongyuan, GUAN Yiduo
《机械工程前沿(英文)》 2008年 第3卷 第4期 页码 360-364 doi: 10.1007/s11465-008-0084-4
关键词: multi-point excitation rectangle-plate single-point processing technology trigonometric interpolation
唐军,沈永明,邱大洪
《中国工程科学》 2007年 第9卷 第4期 页码 70-74
双曲型缓坡方程是研究波浪在近岸缓坡区域传播变形的一种有效波浪数学模型。对Madsen和Larsen 提出的双曲型缓坡方程进行了数值模拟,数值模拟中采用时间层同步空间层交错的有限差分格式对双曲型缓坡 方程进行数值离散,并结合两个典型算例对所采用的数值模型进行验证。数值计算的结果表明,该数值模型可 有效地应用于双曲型缓坡方程的数值求解。
Shaking table testing of hard layered soil-pile-structure interaction system
LI Peizhen, REN Hongmei, LU Xilin, SONG Heping, CHEN Yueqing
《结构与土木工程前沿(英文)》 2007年 第1卷 第3期 页码 346-352 doi: 10.1007/s11709-007-0046-7
关键词: super-structure Generally Magnification frequency different
Development and testing of a wireless smart toolholder with multi-sensor fusion
《机械工程前沿(英文)》 2023年 第18卷 第4期 doi: 10.1007/s11465-023-0774-y
关键词: wireless smart toolholder multi-sensor fusion circular runout dynamic balancing static stiffness dynamic inherent frequency
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
Ali Fadhil NASER, Zonglin WANG
《结构与土木工程前沿(英文)》 2012年 第6卷 第3期 页码 308-320 doi: 10.1007/s11709-012-0140-3
关键词: prestressed concrete box girder monitoring external tendons strain deflection
邴红艳
《中国工程科学》 2004年 第6卷 第2期 页码 82-87
文章在简要回顾路径依赖理论的基础上,运用公司治理路径依赖模型:结构驱动路径依赖和制度驱动的路径依赖模型,揭示了公司治理演进过程中路径依赖的作用机理,并针对中国公司治理演进过程中的路径依赖进行了实证分析。
Model testing of tripod caisson foundations in silty clay subjected to eccentric lateral loads
《结构与土木工程前沿(英文)》 2023年 第17卷 第3期 页码 467-476 doi: 10.1007/s11709-023-0933-6
关键词: tripod caisson foundation silty clay eccentric lateral capacity model tests
Ambient vibration testing and updating of the finite element model of a simply supported beam bridge
Ivan Gomez ARAUJO, Esperanza MALDONADO, Gustavo Chio CHO
《结构与土木工程前沿(英文)》 2011年 第5卷 第3期 页码 344-354 doi: 10.1007/s11709-011-0124-8
关键词: modal analysis parameter identification ambient vibration test Eigensystem Realization Algorithm (ERA) method finite element method
Pengxing YI,Peng HUANG,Tielin SHI
《机械工程前沿(英文)》 2016年 第11卷 第4期 页码 388-402 doi: 10.1007/s11465-016-0404-z
Wind turbine gearbox (WTG), which functions as an accelerator, ensures the performance and service life of wind turbine systems. This paper examines the distinctive modal properties of WTGs through finite element (FE) and experimental modal analyses. The study is performed in two parts. First, a whole system model is developed to investigate the first 10 modal frequencies and mode shapes of WTG using flexible multi-body modeling techniques. Given the complex structure and operating conditions of WTG, this study applies spring elements to the model and quantifies how the bearings and gear pair interactions affect the dynamic characteristics of WTGs. Second, the FE modal results are validated through experimental modal analyses of a 1.5 WM WTG using the frequency response function method of single point excitation and multi-point response. The natural frequencies from the FE and experimental modal analyses show favorable agreement and reveal that the characteristic frequency of the studied gearbox avoids its eigen-frequency very well.
关键词: wind turbine gearbox modal analysis finite element analysis modal frequency bearing equivalence
《环境科学与工程前沿(英文)》 2023年 第17卷 第3期 doi: 10.1007/s11783-023-1636-x
● Environmental parameters affected functional bacteria and network associations.
关键词: Activated sludge Bacterial community Tank-dependence Network association Functional bacteria
Alexey FILIPPOV, Maria KUZNETSOVA, Alexander ROGOZHIN, Olga IAKUSHEVA, Valentina DEMIDOVA, Natalia STATSYUK
《农业科学与工程前沿(英文)》 2018年 第5卷 第4期 页码 462-468 doi: 10.15302/J-FASE-2018239
Late blight is one of the most important potato diseases. To minimize yield losses, various protective measures are used including fungicide application. Active use of fungicides results in a contamination of the environment. Therefore, crop protection strategies optimizing the number of treatments are of great interest. Using information about late blight development in an experimental potato field recorded over 30 seasons, a simulator to forecast yield losses caused by the disease was developed based on the number of 5-d periods favorable for reinfection of plants during a vegetation season. The simulator was successfully verified using independent data on the disease development from nine unprotected potato fields in the Netherlands and Germany. The average difference between the calculated and real yield losses did not exceed 5%. Using the simulator and weather data for a period of 2007-2017, yield losses were calculated for several areas of the Bryansk, Tambov, and Orenburg Regions of Russia. The results revealed differences in disease development between these regions and may be used to develop recommendations for a frequency of fungicide applications according to the regional risk of epidemics, leading to a significant reduction in fungicide use.
关键词: potato late blight Phytophthora infestans yield losses retrospective analysis mathematical model
标题 作者 时间 类型 操作
Dynamic characteristics of a magnetorheological pin joint for civil structures
Yancheng LI,Jianchun LI
期刊论文
Experimental study on the temperature dependence of ultraviolet absorption cross-sections of sulfur dioxide
ZHANG Shiliang, ZHOU Jie, CHEN Xiaohu
期刊论文
Dependence of error sensitivity of frequency on bias voltage in force-balanced micro accelerometer
Lili CHEN, Wu ZHOU
期刊论文
Fundamental frequency and testing mode of complicated elastic clamped-plate vibration
QI Hongyuan, GUAN Yiduo
期刊论文
Shaking table testing of hard layered soil-pile-structure interaction system
LI Peizhen, REN Hongmei, LU Xilin, SONG Heping, CHEN Yueqing
期刊论文
Experimental monitoring of the strengthening construction of a segmental box girder bridge and fieldtesting of external prestressing tendons anchorage
Ali Fadhil NASER, Zonglin WANG
期刊论文
Ambient vibration testing and updating of the finite element model of a simply supported beam bridge
Ivan Gomez ARAUJO, Esperanza MALDONADO, Gustavo Chio CHO
期刊论文
Numerical analysis and experimental investigation of modal properties for the gearbox in wind turbine
Pengxing YI,Peng HUANG,Tielin SHI
期刊论文
Tank-dependence of the functionality and network differentiation of activated sludge community in a full-scale
期刊论文