资源类型

期刊论文 52

年份

2023 3

2022 2

2021 2

2020 4

2019 6

2018 1

2017 3

2015 1

2014 1

2013 4

2012 1

2011 2

2010 3

2009 2

2008 5

2007 5

2006 2

2005 1

2002 1

2001 3

展开 ︾

关键词

距离 2

BP算法 1

EMD距离 1

LMS 1

MixMax模型 1

一致性 1

三峡升船机 1

上海示范线 1

仿真 1

仿真优化 1

决策树;多类不平衡学习;节点划分准则;海林格距离;一对多技术 1

准则 1

减灾 1

分布 1

加密 1

化工 1

区间关联函数 1

区间可拓评价 1

区间距 1

展开 ︾

检索范围:

排序: 展示方式:

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    

Improved directional-distance filter

JIN Lianghai, LI Dehua

《机械工程前沿(英文)》 2008年 第3卷 第2期   页码 205-211 doi: 10.1007/s11465-008-0025-2

摘要: This paper proposes a new spatial-distance weighting function. By combining the weighting function and the traditional directional-distance filter (DDF) in a novel way, a new vector filter - the adaptive distance-weighted directional-distance filter (ADWDDF) - is presented. The experimental results show that the proposed solution provides better filtering performance and preserves better image chromaticity and edge or detail information compared with the traditional DDF and some other typical vector filters.

关键词: information     distance-weighted directional-distance     ADWDDF     traditional DDF     spatial-distance weighting    

Large deflection behavior effect in reinforced concrete columns exposed to extreme dynamic loads

Masoud ABEDINI, Azrul A. MUTALIB, Chunwei ZHANG, Javad MEHRMASHHADI, Sudharshan Naidu RAMAN, Roozbeh ALIPOUR, Tohid MOMENI, Mohamed H. MUSSA

《结构与土木工程前沿(英文)》 2020年 第14卷 第2期   页码 532-553 doi: 10.1007/s11709-020-0604-9

摘要: Reinforced concretes (RC) have been widely used in constructions. In construction, one of the critical elements carrying a high percentage of the weight is columns which were not used to design to absorb large dynamic load like surface bursts. This study focuses on investigating blast load parameters to design of RC columns to withstand blast detonation. The numerical model is based on finite element analysis using LS-DYNA. Numerical results are validated against blast field tests available in the literature. Couples of simulations are performed with changing blast parameters to study effects of various scaled distances on the nonlinear behavior of RC columns. According to simulation results, the scaled distance has a substantial influence on the blast response of RC columns. With lower scaled distance, higher peak pressure and larger pressure impulse are applied on the RC column. Eventually, keeping the scaled distance unchanged, increasing the charge weight or shorter standoff distance cause more damage to the RC column. Intensive studies are carried out to investigate the effects of scaled distance and charge weight on the damage degree and residual axial load carrying capacity of RC columns with various column width, longitudinal reinforcement ratio and concrete strength. Results of this research will be used to assessment the effect of an explosion on the dynamic behavior of RC columns.

关键词: RC column     scaled distance     blast load     LS-DYNA    

Improved numerical method for time domain dynamic structure-foundation interaction analysis based on scaled

DU Jianguo, LIN Gao

《结构与土木工程前沿(英文)》 2008年 第2卷 第4期   页码 336-342 doi: 10.1007/s11709-008-0054-2

摘要: Based on the reduced set of base function in scaled boundary finite element method (SBFEM), an improved time domain numerical approach for the dynamic structure-foundation interaction analysis was proposed. With reasonable choice of the number of base functions, the degrees of freedom on the structure-foundation interface were reduced and the associated computation for the calculation of convolution integral was greatly reduced. The results of this proposed approach applied to the calculation of a gravity dam and an arch dam. The acceleration frequency response functions were calculated and the influences affected by different reduced set of base functions as well as full set were compared. It was found that a higher degree of reduced set of base functions resulted in a significant increase of computational efficiency but a little bit of loss in accuracy. When the reduced set was decreased by 60%, the efficiency may be increased to up to five times, while the loss of accuracy of peak value of response will be less than 4%. It may be concluded that the proposed approach is suitable for large-scale structure-foundation interaction analysis.

关键词: structure-foundation interface     computational efficiency     different     suitable     numerical approach    

investigation of circle defining curve for two-dimensional problem with general boundaries using the scaled

Chung Nguyen VAN

《结构与土木工程前沿(英文)》 2019年 第13卷 第1期   页码 92-102 doi: 10.1007/s11709-018-0472-8

摘要: The scaled boundary finite element method (SBFEM) is applied to the static analysis of two dimensional elasticity problem, boundary value problems domain with the domain completely described by a circular defining curve. The scaled boundary finite element equations is formulated within a general framework integrating the influence of the distributed body force, general boundary conditions, and bounded and unbounded domain. This paper investigates the possibility of using exact geometry to form the exact description of the circular defining curve and the standard finite element shape function to approximate the defining curve. Three linear elasticity problems are presented to verify the proposed method with the analytical solution. Numerical examples show the accuracy and efficiency of the proposed method, and the performance is found to be better than using standard linear element for the approximation defining curve on the scaled boundary method.

关键词: exact geometry     circular defining curve     general boundaries     SBFEM    

Application and evaluation of optical distance measurements in geometrical quality testing of microgears

Albert ALBERS, Duotai PAN, Leif MARXEN, Claudia BECKE,

《机械工程前沿(英文)》 2010年 第5卷 第3期   页码 261-269 doi: 10.1007/s11465-010-0100-3

摘要: Microgears are increasingly important in industry. Compared to normal gears, the quality assurance of microgears needs more accurately measured data and simple but feasible measurement methods because of their dimension particula

关键词: microgear     optical distance measurement     profile deviation     CWL sensor     micromechanical technology (MMT)    

Thermal and hydraulic characteristics of a large-scaled parabolic trough solar field (PTSF) under cloud

Linrui MA, Zhifeng WANG, Ershu XU, Li XU

《能源前沿(英文)》 2020年 第14卷 第2期   页码 283-297 doi: 10.1007/s11708-019-0649-4

摘要: To better understand the characteristics of a large-scaled parabolic trough solar field (PTSF) under cloud passages, a novel method which combines a closed-loop thermal hydraulic model (CLTHM) and cloud vector (CV) is developed. Besides, the CLTHM is established and validated based on a pilot plant. Moreover, some key parameters which are used to characterize a typical PTSF and CV are presented for further simulation. Furthermore, two sets of results simulated by the CLTHM are compared and discussed. One set deals with cloud passages by the CV, while the other by the traditionally distributed weather stations (DWSs). Because of considering the solar irradiance distribution in a more detailed and realistically way, compared with the distributed weather station (DWS) simulation, all essential parameters, such as the total flowrate, flow distribution, outlet temperature, thermal and exergetic efficiency, and exergetic destruction tend to be more precise and smoother in the CV simulation. For example, for the runner outlet temperature, which is the most crucial parameter for a running PTSF, the maximum relative error reaches −15% in the comparison. In addition, the mechanism of thermal and hydraulic unbalance caused by cloud passages are explained based on the simulation.

关键词: parabolic trough solar field (PTSF)     thermal hydraulic model     cloud passages     transients    

New method of fault diagnosis of rotating machinery based on distance of information entropy

Houjun SU, Tielin SHI, Fei CHEN, Shuhong HUANG

《机械工程前沿(英文)》 2011年 第6卷 第2期   页码 249-253 doi: 10.1007/s11465-011-0124-3

摘要:

This paper introduces the basic conception of information fusion and some fusion diagnosis methods commonly used nowadays in rotating machinery. From the thought of the information fusion, a new quantitative feature index monitoring and diagnosing the vibration fault of rotating machinery, which is called distance of information entropy, is put forward on the basis of the singular spectrum entropy in time domain, power spectrum entropy in frequency domain, wavelet energy spectrum entropy, and wavelet space feature entropy in time-frequency domain. The mathematic deduction suggests that the conception of distance of information entropy is accordant with the maximum subordination principle in the fuzzy theory. Through calculation it has been proved that this method can effectively distinguish different fault types. Then, the accuracy of rotor fault diagnosis can be improved through the curve chart of the distance of information entropy at multi-speed.

关键词: rotating machinery     information fusion     fault diagnosis     Information entropy     distance of the information entropy    

Validation of polymer-based nano-iron oxide in further phosphorus removal from bioeffluent: laboratory and scaled-up

Ming HUA, Lili XIAO, Bingcai PAN, Quanxing ZHANG

《环境科学与工程前沿(英文)》 2013年 第7卷 第3期   页码 435-441 doi: 10.1007/s11783-013-0508-1

摘要: The efficient removal of phosphorous from water is an important but challenging task. In this study, we validated the applicability of a new commercially available nanocomposite adsorbent, i.e., a polymer-based hydrated ferric oxide nanocomposite (HFO-201), for the further removal of phosphorous from the bioeffluent discharged from a municipal wastewater treatment plant, and the operating parameters such as the flow rate, temperature and composition of the regenerants were optimized. Laboratory-scale results indicate that phosphorous in real bioeffluent can be effectively removed from 0.92 mg·L to<0.5 mg·L (or even<0.1 mg·L as desired) by the new adsorbent at a flow rate of 50 bed volume (BV) per hour and treatable volume of 3500–4000 BV per run. Phosphorous removal is independent of the ambient temperature in the range of 15°C–40°C. Moreover, the exhausted HFO-201 can be regenerated by a 2% NaOH+ 5% NaCl binary solution for repeated use without significant capacity loss. A scaled-up study further indicated that even though the initial total phosphorus (TP) was as high as 2 mg·L , it could be reduced to<0.5 mg·L , with a working capacity of 4.4–4.8 g·L HFO-201. In general, HFO-201 adsorption is a choice method for the efficient removal of phosphate from biotreated waste effluent.

关键词: bioeffluent     phosphorus removal     nanocomposite adsorbent     hydrated ferric oxide    

influence of hand hole on the ultimate strength and crack pattern of shield tunnel segment joints by scaled

Shaochun WANG, Xi JIANG, Yun BAI

《结构与土木工程前沿(英文)》 2019年 第13卷 第5期   页码 1200-1213 doi: 10.1007/s11709-019-0546-2

摘要: With the shield tunnel going deeper and deeper, the circumferential axial force becomes the governing factor rather than the bending moment. The hand hole acts as a weak point and initial damage in the segment joint especially when the circumferential axial force is extremely high. Despite the wide application of steel fiber or synthetic fiber in the tunneling, limited researches focus on the structural responses of segment joint with macro structural synthetic fiber (MSSF). In this paper, a 1:2 reduced-scale experiment was conducted to study the structural performance of the segment joint with different types of hand holes under ultra-high axial force. Special attention is paid to failure mode and structural performance (bearing capacity, deformation, cracking, and toughness). Moreover, segment joints with MSSF are also tested to evaluate the effects of MSSF on the failure mode and structural performance of the segment joints. The experiment results show that the hand hole becomes the weakest point of the segment joint under ultra-high axial force. A \ /-type crack pattern is always observed before the final failure of the segment joints. Different types and sizes of the hand hole have different degree of influences on the structural behavior of segment joints. The segment joint with MSSF shows higher ultimate bearing capacity and toughness compared to segment joint with common concrete. Besides, the MSSF improves the initial cracking load and anti-spallling resistance of the segment joint.

关键词: shield tunneling     structural synthetic fiber concrete     hand hole     segment joint     ultimate bearing capacity     crack pattern    

Efficient utilization of wind power: Long-distance transmission or local consumption?

Yuanzhang SUN, Xiyuan MA, Jian XU, Yi BAO, Siyang LIAO

《机械工程前沿(英文)》 2017年 第12卷 第3期   页码 440-455 doi: 10.1007/s11465-017-0440-3

摘要:

Excess wind power produced in wind-intensive areas is normally delivered to remote load centers via long-distance transmission lines. This paper presents a comparison between long-distance transmission, which has gained popularity, and local energy consumption, in which a fraction of the generated wind power can be locally consumed by energy-intensive industries. First, the challenges and solutions to the long-distance transmission and local consumption of wind power are presented. Then, the two approaches to the utilization of wind power are compared in terms of system security, reliability, cost, and capability to utilize wind energy. Finally, the economic feasibility and technical feasibility of the local consumption of wind power are demonstrated by a large and isolated industrial power system, or supermicrogrid, in China. The coal-fired generators together with the short-term interruptible electrolytic aluminum load in the supermicrogrid are able to compensate for the intermittency of wind power. In the long term, the transfer of high-energy-consumption industries to wind-rich areas and their local consumption of the available wind power are beneficial.

关键词: wind power     long-distance transmission     local consumption     supermicrogrid    

Cracking resistance performance of super vertical-distance pumped SFRC

JIANG Jinyang, SUN Wei, ZHANG Yunsheng, CHEN Cuicui, WANG Jing

《结构与土木工程前沿(英文)》 2008年 第2卷 第2期   页码 179-183 doi: 10.1007/s11709-008-0018-6

摘要: The mix ratio of steel fiber reinforced concrete (SFRC) was optimized using the principles that workability must meet the pumping demand and anti-cracking performance should be optimal. The effect of SFRC on the initial cracking load, the ultimate load and the crack width of the reinforced concrete (RC) member were analyzed in this paper. It was found that the admixture had good preservation of moisture and adhesion and the fibers distributed homogeneously in one hour out of the machine. According to the pumping results, the SFRC could be pumped vertically up to 306 m. Based on the standard computation formula of cracks, the maximum crack width of an RC member with 0.8% steel fiber (by volume) is about 32% lower than that of standard RC member. Through an experimental research on full-scale model tests for the steel and concrete composite anchorage zone on a pylon, the SFRC not only remarkably increases the crack resistance and the ultimate load, but the initial load also improves 33% approximately. It is also indicated that plastic shrinkage cracking of SFRC in which volume fraction of steel fibers is 0.8% can be restrained obviously and the unrestrained drying shrinkage can be diminished by about 50% at early age. The results confirmed that the SFRC can lessen the shrinkage crack of concrete and enhance markedly the direct tensile strength. Therefore, the SFRC can solve the key question of crack resistance for the anchorage zone of a bridge tower.

Variable eccentric distance-based tool path generation for orthogonal turn-milling

Fangyu PENG,Wei WANG,Rong YAN,Xianyin DUAN,Bin LI

《机械工程前沿(英文)》 2015年 第10卷 第4期   页码 352-366 doi: 10.1007/s11465-015-0361-y

摘要:

This study proposes an algorithm for maximizing strip width in orthogonal turn-milling based on variable eccentric distance. The machining error model is first established based on the local cutting profile at the contact line. The influencing factors of the strip width are then investigated to analyze their features and determine an optimizing strategy. The optimized model for maximum machining strip width is formulated by adopting a variable eccentric distance. Hausdorff distance and Fréchet distance are introduced in this study to implement the constraint function of the machining error in the optimized model. The computing procedure is subsequently provided. Simulations and experiments have been conducted to verify the effectiveness of the proposed algorithm.

关键词: orthogonal turn-milling     variable eccentric distance     local cutting profile     machining strip-width maximization    

论减灾系统的远程公平化

姚清林

《中国工程科学》 2009年 第11卷 第6期   页码 153-158

摘要:

远程公平化是偏向于远程的公平,旨在寻求系统整体的优化。在一定的约束条件下,通过域的分隔、变形,中心的定位与相应的远程运作机制,可消减不利因素对系统的干扰,扩大结构瓶颈,调优技术性弱点、难点、远点、易忽视点的指标期望与实现值,抑小扬大,隐近就远,弥补系统缺陷,或于不完备的条件下构建 完备系统,保障全局利益与远效,推进减灾管理的科学化,改善各个方面的减灾工作。

关键词: 远程公平化     减灾     管理     地震    

中心节点距离对树状网络一致性的影响

李达权,孙伟刚,胡鸿翔

《信息与电子工程前沿(英文)》 2023年 第24卷 第9期   页码 1349-1356 doi: 10.1631/FITEE.2200400

摘要: 本文研究了两个中心节点之间的距离对网络一致性的影响。网络一致性由拉普拉斯特征值所量化,可用来衡量线性系统对外部噪声的一致性程度。为获得网络一致性关于距离的精确表达式,选取一类由网络参数控制的具有两个中心节点的树状网络。利用其规则的拓扑结构,得到一致性关于网络参数和网络规模的解析表达式。证明两个中心节点距离越短,度的差异性越大,网络一致性越好。在相同网络规模和距离下,最大的中心节点度差异会导致最优的一致性。最后,建立了网络一致性与平均路径长度之间的联系,发现它们呈线性关系。

关键词: 一致性     距离     平均路径长度    

标题 作者 时间 类型 操作

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

Janice B. D’SOUZA, Sangarapillai KANAPATHIPILLAI

期刊论文

Improved directional-distance filter

JIN Lianghai, LI Dehua

期刊论文

Large deflection behavior effect in reinforced concrete columns exposed to extreme dynamic loads

Masoud ABEDINI, Azrul A. MUTALIB, Chunwei ZHANG, Javad MEHRMASHHADI, Sudharshan Naidu RAMAN, Roozbeh ALIPOUR, Tohid MOMENI, Mohamed H. MUSSA

期刊论文

Improved numerical method for time domain dynamic structure-foundation interaction analysis based on scaled

DU Jianguo, LIN Gao

期刊论文

investigation of circle defining curve for two-dimensional problem with general boundaries using the scaled

Chung Nguyen VAN

期刊论文

Application and evaluation of optical distance measurements in geometrical quality testing of microgears

Albert ALBERS, Duotai PAN, Leif MARXEN, Claudia BECKE,

期刊论文

Thermal and hydraulic characteristics of a large-scaled parabolic trough solar field (PTSF) under cloud

Linrui MA, Zhifeng WANG, Ershu XU, Li XU

期刊论文

New method of fault diagnosis of rotating machinery based on distance of information entropy

Houjun SU, Tielin SHI, Fei CHEN, Shuhong HUANG

期刊论文

Validation of polymer-based nano-iron oxide in further phosphorus removal from bioeffluent: laboratory and scaled-up

Ming HUA, Lili XIAO, Bingcai PAN, Quanxing ZHANG

期刊论文

influence of hand hole on the ultimate strength and crack pattern of shield tunnel segment joints by scaled

Shaochun WANG, Xi JIANG, Yun BAI

期刊论文

Efficient utilization of wind power: Long-distance transmission or local consumption?

Yuanzhang SUN, Xiyuan MA, Jian XU, Yi BAO, Siyang LIAO

期刊论文

Cracking resistance performance of super vertical-distance pumped SFRC

JIANG Jinyang, SUN Wei, ZHANG Yunsheng, CHEN Cuicui, WANG Jing

期刊论文

Variable eccentric distance-based tool path generation for orthogonal turn-milling

Fangyu PENG,Wei WANG,Rong YAN,Xianyin DUAN,Bin LI

期刊论文

论减灾系统的远程公平化

姚清林

期刊论文

中心节点距离对树状网络一致性的影响

李达权,孙伟刚,胡鸿翔

期刊论文