Search | Engineering

订阅投稿

首页学术期刊学术焦点学术视频工程成就工程前沿联系我们 English

资源类型

期刊论文 118

年份

2022 4

2021 4

2020 7

2019 7

2017 5

2016 6

2015 7

2014 3

2013 2

2012 5

2011 5

2010 7

2009 10

2008 13

2007 8

2006 3

2005 4

2004 4

2003 7

2002 2

展开︾

关键词

模拟试验 4

模型试验 3

工程水压爆破 2

模态 2

CECE-GC 1

CO 1

K型钢管混凝土节点 1

Lorentz 1

Matlab/Simulink仿真 1

S—N曲线 1

三峡升船机 1

三峡大坝 1

三态组织 1

三星一线 1

下泄水温公式 1

中药 1

中间塔 1

二维插值 1

交通导致振动 1

展开︾

检索范围：

排序：展示方式：

Numerical analysis and experimental investigation of modal properties for the gearbox in wind turbine

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

摘要：

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

HTML PDF 收藏

Multi-objective genetic algorithms based structural optimization and experimental investigation of the planet carrier in wind turbine gearbox

Pengxing YI,Lijian DONG,Tielin SHI

《机械工程前沿（英文）》 2014年第9卷第4期页码 354-367 doi: 10.1007/s11465-014-0319-5

摘要：

To improve the dynamic performance and reduce the weight of the planet carrier in wind turbine gearbox, a multi-objective optimization method, which is driven by the maximum deformation, the maximum stress and the minimum mass of the studied part, is proposed by combining the response surface method and genetic algorithms in this paper. Firstly, the design points’ distribution for the design variables of the planet carrier is established with the central composite design (CCD) method. Then, based on the computing results of finite element analysis (FEA), the response surface analysis is conducted to find out the proper sets of design variable values. And a multi-objective genetic algorithm (MOGA) is applied to determine the direction of optimization. As well, this method is applied to design and optimize the planet carrier in a 1.5 MW wind turbine gearbox, the results of which are validated by an experimental modal test. Compared with the original design, the mass and the stress of the optimized planet carrier are respectively reduced by 9.3% and 40%. Consequently, the cost of planet carrier is greatly reduced and its stability is also improved.

关键词： planet carrier multi-objective optimization genetic algorithms wind turbine gearbox modal experiment

HTML PDF 收藏

Experimental and computational validation of a scaled train tunnel model using modal analysis

Janice B. D’SOUZA, Sangarapillai KANAPATHIPILLAI

《机械工程前沿（英文）》 2013年第8卷第4期页码 420-428 doi: 10.1007/s11465-013-0281-7

摘要：

Acoustic engineers are faced with the challenge of minimising reverberation time in their designs so as to contribute to the health and well-being of those traveling by train and those on the platforms. Although the problem is easy to identify, it is not as simple to solve. The acoustical environment of a train tunnel is complex, with a variety of noise contributing factors such as train announcements, speech of commuters, ventilation systems, electrical equipment and wheel and rail noise. As a result, there is some difficulty in modeling the complete acoustic environment with computational or acoustic first principles. In this study, an experimental rig was constructed to model the acoustic behavior within a tunnel. The modal properties for the 300 Hz to 1500 Hz range, including resonances and mode shapes were identified and were shown to successfully correspond to theoretical results and a computational model created in COMSOL using Finite Element Analysis.

关键词： reverberation time acoustic environment modal properties resonances

HTML PDF 收藏

Variational mode decomposition based modal parameter identification in civil engineering

Mingjie ZHANG, Fuyou XU

《结构与土木工程前沿（英文）》 2019年第13卷第5期页码 1082-1094 doi: 10.1007/s11709-019-0537-3

摘要： An out-put only modal parameter identification method based on variational mode decomposition (VMD) is developed for civil structure identifications. The recently developed VMD technique is utilized to decompose the free decay response (FDR) of a structure into to modal responses. A novel procedure is developed to calculate the instantaneous modal frequencies and instantaneous modal damping ratios. The proposed identification method can straightforwardly extract the mode shape vectors using the modal responses extracted from the FDRs at all available sensors on the structure. A series of numerical and experimental case studies are conducted to demonstrate the efficiency and highlight the superiority of the proposed method in modal parameter identification using both free vibration and ambient vibration data. The results of the present method are compared with those of the empirical mode decomposition-based method, and the superiorities of the present method are verified. The proposed method is proved to be efficient and accurate in modal parameter identification for both linear and nonlinear civil structures, including structures with closely spaced modes, sudden modal parameter variation, and amplitude-dependent modal parameters, etc.

关键词： modal parameter identification variational mode decomposition civil structure nonlinear system closely spaced modes

HTML PDF 收藏

Experimental study of structural damage identification based on modal parameters and decay ratio of acceleration

Zhigen WU, Guohua LIU, Zihua ZHANG

《结构与土木工程前沿（英文）》 2011年第5卷第1期页码 112-120 doi: 10.1007/s11709-010-0069-3

摘要： A novel damage assessment method based on the decay ratio of acceleration signals (DRAS) was proposed. Two experimental tests were used to show the efficiency. Three beams were gradually damaged, and then the changes of dynamic parameters were monitored from initial to failure state. In addition, a new method was compared with the linear modal-based damage assessment using wavelet transform (WT). The results clearly show that DRAS increases in linear elasticity state and microcrack propagation state, while DRAS decreases in macrocrack propagation state. Preliminary analysis was developed considering the beat phenomenon in the nonlinear state to explain the turn point of DRAS. With better sensibility of damage than modal parameters, probably DRAS is a promising damage indicator in damage assessment.

关键词： damage assessment decay ratio of acceleration signals (DRAS) wavelet transform (WT) modal analysis reinforced concrete beam beat phenomenon

HTML PDF 收藏

network for damage detection in functionally graded carbon nanotube-reinforced composite plates using modal

《结构与土木工程前沿（英文）》 2021年第15卷第6期页码 1453-1479 doi: 10.1007/s11709-021-0767-z

摘要： This paper proposes a new Deep Feed-forward Neural Network (DFNN) approach for damage detection in functionally graded carbon nanotube-reinforced composite (FG-CNTRC) plates. In the proposed approach, the DFNN model is developed based on a data set containing 20 000 samples of damage scenarios, obtained via finite element (FE) simulation, of the FG-CNTRC plates. The elemental modal kinetic energy (MKE) values, calculated from natural frequencies and translational nodal displacements of the structures, are utilized as input of the DFNN model while the damage locations and corresponding severities are considered as output. The state-of-the art Exponential Linear Units (ELU) activation function and the Adamax algorithm are employed to train the DFNN model. Additionally, in order to enhance the performance of the DFNN model, the mini-batch and early-stopping techniques are applied to the training process. A trial-and-error procedure is implemented to determine suitable parameters of the network such as the number of hidden layers and the number of neurons in each layer. The accuracy and capability of the proposed DFNN model are illustrated through two distinct configurations of the CNT-fibers constituting the FG-CNTRC plates including uniform distribution (UD) and functionally graded-V distribution (FG-VD). Furthermore, the performance and stability of the DFNN model with the consideration of noise effects on the input data are also investigated. Obtained results indicate that the proposed DFNN model is able to give sufficiently accurate damage detection outcomes for the FG-CNTRC plates for both cases of noise-free and noise-influenced data.

关键词： damage detection deep feed-forward neural networks functionally graded carbon nanotube-reinforced composite plates modal kinetic energy

HTML PDF 收藏

Control mode selection for modal control of long-span arch bridge

Zhengying LI, Zhengliang LI,

《结构与土木工程前沿（英文）》 2009年第3卷第4期页码 401-406 doi: 10.1007/s11709-009-0052-z

摘要： For seismic control of arch bridge, a model reduction of long-span arch bridge was implemented based on modal analysis. As for the critical mode selection, an approach based on the maximum modal displacement was presented. This approach takes into consideration the effect of external seismic excitation and is more reasonable than only considering dynamic bridge characteristics based on a modal contribution ratio. The time domain and frequency domain analysis method were used to verify the simplified model of the Nimu arch bridge in Tibet as an example. The numerical results show that the method of maximal modal displacement better analyze long-span arch bridge when multisupport seismic excitation must be considered. The reduced-order system also is more in line with the performance of the original model.

关键词： selection reduced-order excitation long-span simplified

HTML PDF 收藏

Experimental study of modal parameter identification in a simulated ambient-excited structure

JI Xiaodong, QIAN Jiaru, XU Longhe

《结构与土木工程前沿（英文）》 2007年第1卷第3期页码 281-285 doi: 10.1007/s11709-007-0036-9

摘要： Structure modal parameter online identification was used to monitor the structural health as evidenced by changes in the vibration characteristics. The natural excitation technique and the eigensystem realization algorithm were combined to identify the modal parameters in the time domain of a structure excited by simulated ambient vibrations. The mass-normalized mode shapes were obtained from the eigen-sensitivity analysis. The experimental modal analysis was performed on a two-story steel braced frame model excited by simulated ambient vibrations and hammer impacts. The mass-normalized mode shapes were acquired by changing the structural mass and by eigen-sensitivity analy sis. From finite element analysis results and the experimental data, it is shown that this method is effective.

关键词： eigensystem realization eigen-sensitivity analysis realization algorithm vibration effective

HTML PDF 收藏

A method of analysis for modal aero-damping of vibrating blade in incompressible flow

Jun XING, Lin LI,

《能源前沿（英文）》 2009年第3卷第4期页码 465-471 doi: 10.1007/s11708-009-0037-6

摘要： By establishing a research model for aero-damping in a uniform incoming flow, the three-dimension analytical algorithm of the modal aero-damping based on the equivalent viscous damping principle was established. The algorithm, which is suited for low-speed flow, to compute aero-damping is based on classical lift line theory in aerodynamics, according to the analytical solution of unsteady aerodynamic force. According to the analytical equations, the modal aero-damping ratio for different nature frequencies of blades in various fluid field conditions can be solved, and the factors to affect the aero-damping can be determined.The first bend and the first torsion’s modal aero-damping ratios of a compressor blade are calculated by using the above algorithms. The results show that the aero-damping cannot be neglected comparing with the structure damping. It reflects the coupling degree between the flow field and the structure field, so the aero-damping is significant to compute the stress and life of blade.

关键词： compressor different three-dimension analytical classical low-speed

HTML PDF 收藏

近β锻造推翻陈旧理论发展了三态组织

周义刚,曾卫东,俞汉清

《中国工程科学》 2001年第3卷第5期页码 61-66

摘要：

将坯料置于相变的临界点附近10～15℃加热、锻造、锻后水冷，随后，不是采用时效处理，而是先进行高温韧化再低温强化处理。近β锻造的组织不再是等轴α量过多，或是为零的网篮条状α的结构模式；而是约含20%等轴α、50%～60%条状α构成的网篮和β转变基体组成的三态组织。这种结构不仅丰富和发展了国际上钛合金已有的4种组织类塑（等轴、双态、网篮和并列），而且将等轴和网篮组织的性能优势集于一身，由此带来的力学性能超过了国内外相关技术的性能水平：能在不降低塑性，不丧失热稳定性的条件下，提高材料的高温性能、低周疲劳性能和断裂韧性，在改善性能的同时提高使用温度。近β锻造适用于（α+β)型合金，还可应用于α、近α和近β型合金，其研究成果已用于制造了多种发动机盘件、飞机和导弹等重要结构件。

关键词：钛合金近β锻造三态组织

HTML PDF 收藏

Biaxial tensile-compressive experiment of concrete at high temperatures

SONG Yupu, ZHANG Zhong, QING Likun, YU Changjiang

《结构与土木工程前沿（英文）》 2007年第1卷第1期页码 94-98 doi: 10.1007/s11709-007-0009-z

摘要： Biaxial tension-compression experiments of concrete of five stress ratios at high temperatures were carried out using the large static-dynamic triaxial test system in the State Key Laboratory of Coastal and Offshore Engineering, Dalian University of Technology. The stress ratios s1/s3 are 0, 0.1, 0.25, 0.50, and 0.75. The temperatures are 20vH, 200vH, 300vH, 500vH, 600vH. The mechanical behavior of concrete under biaxial tension-compression at high temperatures is analyzed. It is found that both the tensile strength and strain diminished with the increase in temperature under each stress ratio. Based on the test results, the relationship between tensile strengths and stress ratios and temperature is proposed. In addition, the failure criterion of concrete under biaxial stress state of tension-compression at high temperatures is established.

关键词： increase Offshore Engineering temperature relationship addition

HTML PDF 收藏

Numerical simulation and experiment research of radiation performance in a dish solar collector system

Yong SHUAI, Xinlin XIA, Heping TAN

《能源前沿（英文）》 2010年第4卷第4期页码 488-495 doi: 10.1007/s11708-010-0007-z

摘要： The Monte Carlo ray-tracing method is applied and coupled with optical properties to predict the radiation performance of solar concentrator/cavity receiver systems. Several different cavity geometries are compared on the radiation performance. A flux density distribution measurement system for dish parabolic concentrators is developed. The contours of the flux distribution for target placements at different distances from the dish vertex of a solar concentrator are taken by using an indirect method with a Lambert and a charge coupled device (CCD) camera. Further, the measured flux distributions are compared with a Monte Carlo-predicted distribution. The results can be a valuable reference for the design and assemblage of the solar collector system.

关键词： Monte Carlo method solar energy radiation performance cavity receiver

HTML PDF 收藏

Centrifuge experiment and numerical analysis of an air-backed plate subjected to underwater shock loading

Zhijie HUANG, Xiaodan REN, Zuyu CHEN, Daosheng LING

《结构与土木工程前沿（英文）》 2019年第13卷第6期页码 1350-1362 doi: 10.1007/s11709-019-0559-x

摘要： In this study, systematic centrifuge experiments and numerical studies are conducted to investigate the effect of shock loads due to an underwater explosion on the dynamic responses of an air-backed steel plate. Numerical simulations with three different models of pressure time history generated by underwater explosion were carried out. The first model of pressure time history was measured in test. The second model to predict the time history of shock wave pressure from an underwater explosion was created by Cole in 1948. Coefficients of Cole’s formulas are determined experimentally. The third model was developed by Zamyshlyaev and Yakovlev in 1973. All of them are implemented into the numerical model to calculate the shock responses of the plate. Simulated peak strains obtained from the three models are compared with the experimental results, yielding average relative differences of 21.39%, 45.73%, and 13.92%, respectively. The Russell error technique is used to quantitatively analyze the correlation between the numerical and experimental results. Quantitative analysis shows that the simulated strains for most measurement points on the steel plate are acceptable. By changing the scaled distances, different shock impulses were obtained and exerted on the steel plate. Systematic numerical studies are performed to investigate the effect of the accumulated shock impulse on the peak strains. The numerical and experimental results suggest that the peak strains are strongly dependent on the accumulated shock impulse.

关键词： underwater explosion centrifuge experiment shock load dynamic response accumulated shock impulse

HTML PDF 收藏

Parameter for judging reactivity of coal and coke

HE Hongzhou, LUO Zhongyang, CEN Kefa

《能源前沿（英文）》 2008年第2卷第3期页码 354-358 doi: 10.1007/s11708-008-0052-z

摘要： To eliminate the judgment error of char reactivity arising from different carbon content of samples, a new parameter called specific maximum weight loss rate was introduced. It is defined as the quotient of the maximum weight loss rate in non-isothermal thermogravimetric analysis (TGA) experiment to the carbon content of the corresponding sample. The reactivity of different kinds of coal, the reactivity of the same coal type with different lithotype, and the reactivity of the char with different carbon conversion rates were checked by using the specific maximum weight loss rate, and the results were analyzed and compared with those obtained by using other criteria. The results show that the specific maximum weight loss rate can be used as a commonality parameter to evaluate and distinguish the reactivity of different coal and char. The heating rate selected in TGA experiment has no effect on the judgment.

关键词： thermogravimetric analysis specific maximum different lithotype experiment TGA experiment

HTML PDF 收藏

陆空协同多模态智能机器人系统发展战略研究

黄强,孟非,余张国,林德福,徐彬,朵英贤

《中国工程科学》 2021年第23卷第5期页码 116-121 doi: 10.15302/J-SSCAE-2021.05.015

摘要：

陆空协同多模态智能机器人系统能够适应陆空环境，具有多模态特征，具有高级智能，能够协同完成复杂任务。该系统在社会各领域具有广泛应用前景，是促进全球科技、社会、经济发展的新动能。本文针对发展我国陆空协同多模态智能机器人系统的重大需求，全面分析了该领域的国内外发展现状和我国目前存在的问题，我国的地面、空中机器人及智能系统与国外存在较大差距，但是陆空协同机器人系统各国都还处于起步阶段，具有超越可能。本文提出了贯穿理论与关键技术、核心部件与单元、平台与系统装备，以及系统应用的发展目标、发展布局、发展路线图和政策建议等，从而形成相关技术体系、核心部件产业体系、智能机器人装备体系以及社会应用。研究表明陆空协同多模态智能机器人系统未来能够全方位融入智慧社会，应用于智慧医疗、教育、家居、交通、制造等领域，服务国计民生。

关键词：智能机器人陆空协同多模态人工智能

HTML PDF 收藏

标题作者时间类型操作

Numerical analysis and experimental investigation of modal properties for the gearbox in wind turbine

Pengxing YI,Peng HUANG,Tielin SHI

期刊论文

Multi-objective genetic algorithms based structural optimization and experimental investigation of the planet carrier in wind turbine gearbox

Pengxing YI,Lijian DONG,Tielin SHI

期刊论文

Experimental and computational validation of a scaled train tunnel model using modal analysis

Janice B. D’SOUZA, Sangarapillai KANAPATHIPILLAI

期刊论文

Variational mode decomposition based modal parameter identification in civil engineering

Mingjie ZHANG, Fuyou XU

期刊论文

Experimental study of structural damage identification based on modal parameters and decay ratio of acceleration

Zhigen WU, Guohua LIU, Zihua ZHANG

期刊论文

network for damage detection in functionally graded carbon nanotube-reinforced composite plates using modal

期刊论文

Control mode selection for modal control of long-span arch bridge

Zhengying LI, Zhengliang LI,

期刊论文

Experimental study of modal parameter identification in a simulated ambient-excited structure

JI Xiaodong, QIAN Jiaru, XU Longhe

期刊论文

A method of analysis for modal aero-damping of vibrating blade in incompressible flow

Jun XING, Lin LI,

期刊论文

近β锻造推翻陈旧理论发展了三态组织

周义刚,曾卫东,俞汉清

期刊论文

Biaxial tensile-compressive experiment of concrete at high temperatures

SONG Yupu, ZHANG Zhong, QING Likun, YU Changjiang

期刊论文

Numerical simulation and experiment research of radiation performance in a dish solar collector system

Yong SHUAI, Xinlin XIA, Heping TAN

期刊论文

Centrifuge experiment and numerical analysis of an air-backed plate subjected to underwater shock loading

Zhijie HUANG, Xiaodan REN, Zuyu CHEN, Daosheng LING

期刊论文

Parameter for judging reactivity of coal and coke

HE Hongzhou, LUO Zhongyang, CEN Kefa

期刊论文

陆空协同多模态智能机器人系统发展战略研究

黄强,孟非,余张国,林德福,徐彬,朵英贤

期刊论文

京公网安备 11010502051620号京ICP备11030251号-2

关注我们