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电力系统；脆弱性；连锁故障；多图卷积网络；加权线图 1

迷宫式泄洪道 1

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Assessment of fatigue life of remanufactured impeller based on FEA

Lei XU,Huajun CAO,Hailong LIU,Yubo ZHANG

《机械工程前沿（英文）》 2016年第11卷第3期页码 219-226 doi: 10.1007/s11465-016-0394-x

摘要：

Predicting the fatigue life of remanufactured centrifugal compressor impellers is a critical problem. In this paper, the S-N curve data were obtained by combining experimentation and theory deduction. The load spectrum was compiled by the rain-flow counting method based on the comprehensive consideration of the centrifugal force, residual stress, and aerodynamic loads in the repair region. A fatigue life simulation model was built, and fatigue life was analyzed based on the fatigue cumulative damage rule. Although incapable of providing a high-precision prediction, the simulation results were useful for the analysis of fatigue life impact factors and fatigue fracture areas. Results showed that the load amplitude greatly affected fatigue life, the impeller was protected from running at over-speed, and the predicted fatigue life was satisfied within the next service cycle safely at the rated speed.

关键词： remanufactured impeller fatigue life impeller failures finite element analysis (FEA)

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Mesoscale fabrication of a complex surface for integral impeller blades

Xibin WANG,Tianfeng ZHOU,Lijing XIE,Li JIAO,Zhibing LIU,Zhiqiang LIANG,Pei YAN

《机械工程前沿（英文）》 2017年第12卷第1期页码 116-131 doi: 10.1007/s11465-017-0426-1

摘要：

Integral impeller is the most important component of a mini-engine. However, the machining of a mesoscale impeller with a complex integral surface is difficult because of its compact size and high accuracy requirement. A mesoscale component is usually manufactured by milling. However, a conventional milling tool cannot meet the machining requirements because of its size and stiffness. For the fabrication of a complex integral impeller, a micro-ball-end mill is designed in accordance with the non-instantaneous-pole envelope principle and manufactured by grinding based on the profile model of the helical groove and the mathematical model of the cutting edge curve. Subsequently, fractal theory is applied to characterize the surface quality of the integral impeller. The fractal theory-based characterization shows that the completed mesoscale integral impeller exhibits a favorable performance in terms of mechanical properties and morphological accuracy.

关键词： mesoscale fabrication micro-milling tool mesoscale milling impeller blade

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Damage mechanism and evaluation model of compressor impeller remanufacturing blanks: A review

Haiyang LU, Yanle LI, Fangyi LI, Xingyi ZHANG, Chuanwei ZHANG, Jiyu DU, Zhen LI, Xueju RAN, Jianfeng LI, Weiqiang WANG

《机械工程前沿（英文）》 2019年第14卷第4期页码 402-411 doi: 10.1007/s11465-019-0548-8

摘要： The theoretical and technological achievements in the damage mechanism and evaluation model obtained through the national basic research program “Key Fundamental Scientific Problems on Mechanical Equipment Remanufacturing” are reviewed in this work. Large centrifugal compressor impeller blanks were used as the study object. The materials of the blanks were FV520B and KMN. The mechanism and evaluation model of ultra-high cycle fatigue, erosion wear, and corrosion damage were studied via theoretical calculation, finite element simulation, and experimentation. For ultra-high cycle fatigue damage, the characteristics of ultra-high cycle fatigue of the impeller material were clarified, and prediction models of ultra-high cycle fatigue strength were established. A residual life evaluation technique based on the “ - - ” (where was the nonlinear parameter, was the Vickers hardness, and was the fatigue life) double criterion method was proposed. For erosion wear, the flow field of gas-solid two-phase flow inside the impeller was simulated, and the erosion wear law was clarified. Two models for erosion rate and erosion depth calculation were established. For corrosion damage, the electrochemical and stress corrosion behaviors of the impeller material and welded joints in H S/CO environment were investigated. (critical stress intensity factor) and d /d (crack growth rate, where is the total crack length and is time) varied with H S concentration and temperature, and their variation laws were revealed. Through this research, the key scientific problems of the damage behavior and mechanism of remanufacturing objects in the multi-strength field and cross-scale were solved. The findings provide theoretical and evaluation model support for the analysis and evaluation of large centrifugal compressor impellers before remanufacturing.

关键词： remanufacturing centrifugal compressor impeller remanufacturing blank damage mechanism evaluation model

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连锁故障中电力系统脆弱性的多图卷积网络分析 Research Article

Supaporn LONAPALAWONG1,陈长胜2,王灿3,陈为1

《信息与电子工程前沿（英文）》 2022年第23卷第12期页码 1848-1861 doi: 10.1631/FITEE.2200035

摘要：分析电力系统在连锁故障中的薄弱环节是电力系统分析领域极具挑战的难题。电力系统领域的传统分析方法虽能发现一些简单的传播规律，但却难以捕捉不同运行条件下的复杂细节。近年来的研究引入了深度学习算法来解决这一难题。然而，现有基于深度学习的方法大多仅从拓扑层面考虑电力系统的网架结构，未能充分考虑空间信息（如电距离）以提高图卷积过程的精确度。鉴于此，本文提出一种新型电力系统加权线图，综合考虑电力系统拓扑结构和空间信息，大幅优化线图的边权分配。此外，本文提出一种基于图分类任务的多图卷积网络（MGCN），在保留电力系统空间相关性的同时有效捕获物理元件之间的关联。经验证，该模型能够在具有额外拓扑特征的建模系统中保持理想精度，从而更好地分析存在并行输电线路的复杂连锁故障。最后，本文采用逐层相关传播方法解释MGCN，并量化了模型分类的贡献因子，有效提升模型的可解释性。

关键词：电力系统；脆弱性；连锁故障；多图卷积网络；加权线图

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大坝和洪水

F. Lempérière

《工程（英文）》 2017年第3卷第1期页码 144-149 doi: 10.1016/J.ENG.2017.01.018

摘要：

大坝对洪水的削弱作用和大坝面对洪水时的风险是本文讨论的两个主题。中国成功和高效地进行了大坝建设，正在引领世界上该领域的发展。本文致力于研究其他国家的相关经验、从数个世纪以来的事故中获得的教训以及新的解决方案。按照坝高、库容、筑坝材料和泄洪数据对洪水灾害进行分析，结果表明，多数重大事故发生于库容超过10 hm³的土石坝。新的解决方案对大坝安全和防洪来说都具有良好的前景。

关键词：洪水防洪泄洪道迷宫式泄洪道溃坝

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Optimal ratio of bend channel in centrifugal compressor

WEN Suping, HU Xiaowen, LI Tingbin, ZHANG Yong, WANG Jun

《能源前沿（英文）》 2008年第2卷第4期页码 381-385 doi: 10.1007/s11708-008-0084-4

摘要： A numerical investigation on the flow in a bend channel by coupling the impeller with the vaneless diffuser in a centrifugal compressor with different ratios (bend radius to bend channel width ) is presented. The jet-wake effect of the impeller outlet is considered and flow pattern in the bend channel and the performance of the centrifugal compressor stage are investigated. The results indicate that there is an optimal ratio for increasing the stage efficiency to the highest for a specific compressor stage. The change in ratio significantly affects the flow angle of the bend channel outlet. The prime reason for the total pressure loss in the bend channel is the wall friction in the bend channel.

关键词： specific compressor different centrifugal compressor pressure impeller

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Fragility assessment of wood sheathing panels and roof-to-wall connections subjected to wind loading

《结构与土木工程前沿（英文）》 2021年第15卷第4期页码 867-876 doi: 10.1007/s11709-021-0745-5

摘要： The performance of the wood-frame buildings after tornadoes has shown that the majority of the wind damage resulted from building envelope failure most typically due to the loss of the roof. To assess the performance and the reliability of low-rise wood-frame residential buildings with a focus on the roofs, fragility analysis can be used to estimate the probability of failure of a roof when constructed with specified nails and sheathing sizes. Thus, this paper examines the fragility of specific types of nails, roof-to-wall (RW) connection details, and sheathing sizes based on the damaged roofs that were previously assessed in the Dunrobin area in Ottawa (Ontario) that was hit with an Enhanced Fujita (EF3) tornado on September 21, 2018. The presented fragility analysis considers four scenarios, including different sheathing and nail sizes. Dead loads, wind loads, and resistance on the sheathing panels were compiled and analyzed to determine the failure of the examined roofs. The eight fragility models suggest that the safest roof sheathing (RS) is the 1.22 m × 1.22 m sheathing panel with 8 d nails, and the safest RW connections is achieved by using H2.5 hurricane clips.

关键词： tornadoes wind loads low-rise buildings fragility analysis risk assessment structural failures

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Five-axis rough machining for impellers

Ruolong QI, Weijun LIU, Hongyou BIAN, Lun LI

《机械工程前沿（英文）》 2009年第4卷第1期页码 71-76 doi: 10.1007/s11465-009-0010-4

摘要： The most important components used in aerospace, ships, and automobiles are designed with free form surfaces. An impeller is one of the most important components that is difficult to machine because of its twisted blades. Rough machining is recognized as the most crucial procedure influencing machining efficiency and is critical for the finishing process. An integrated rough machining course with detailed algorithms is presented in this paper. An algorithm for determining the minimum distance between two surfaces is applied to estimate the tool size. The space between two blades that will be cleared from the roughcast is divided to generate CC points. The tool axis vector is confirmed based on flank milling using a simple method that could eliminate global interference between the tool and the blades. The result proves that the machining methodology presented in this paper is useful and successful.

关键词： five-axis impeller tool-path planning flank milling ruled surface

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Noise reduction for centrifugal fan with non-isometric forward-swept blade impeller

MA Jianfeng, QI Datong, MAO Yijun

《能源前沿（英文）》 2008年第2卷第4期页码 433-437 doi: 10.1007/s11708-008-0082-6

摘要： To reduce the noise of the T9-19No.4A centrifugal fan, whose impeller has equidistant forward-swept blades, two new impellers with different blade spacing were designed and an experimental study was conducted. Both the fan’s aerodynamic performance and noise were measured when the two redesigned impellers were compared with the original ones. The test results are discussed in detail and the effect of the noise reduction method for a centrifugal fan using impellers with non-isometric forward-swept blades was analyzed, which can serve as a reference for researches on reduction of fan noise.

关键词： different reference aerodynamic performance centrifugal impeller

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Cavitation in semi-open centrifugal impellers for a miniature pump

LUO Xianwu, LIU Shuhong, ZHANG Yao, XU Hongyuan

《能源前沿（英文）》 2008年第2卷第1期页码 31-35 doi: 10.1007/s11708-008-0011-8

摘要： Cavitation in miniature pumps was investigated experimentally for two semi-open centrifugal impellers. Although both impellers had the same blade cross-section, one impeller had a two-dimensional blade, while the other had a leaned blade. The flows were also analyzed using a numerical model of the three-dimensional turbulent flow in the pumps near the peak efficiency point using the -? turbulence model and the VOF cavitation model. The average cavitation performance of each impeller was satisfactorily predicted by the numerical simulations. The results show that the miniature pumps have similar cavitation performances as an ordinary-size pump, with the cavitation performance of the semi-open impeller reduced by increased axial tip clearances. Also, both the hydraulic and cavitation performance of the semi-open impeller were improved by the leaned blade. The results also show that uniform flow upstream of the impeller inlet will improve the cavitation performance of a miniature pump.

关键词： cavitation performance semi-open impeller increased two-dimensional efficiency