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Die design for cold precision forging of bevel gear based on finite element method

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Journal of Central South University 2009年第4期16卷 546-551页

作者：金俊松夏巨谌王新云胡国安刘华 State Key Laboratory of Material Process and Die & Mould Technology Huazhong University of Science and Technology Metal Forming Division Zhengzhou Research Institute of Mechanical Engineering

The finite element analysis （FEA） software Ansys was employed to study the stress state of the dies of both plane and non-plane parting face structures with uniform interference and the die of plane parting face structure with non-uniform interference. Considering the symmetry of the die, a half gear tooth model of the two-ring assembled die with 2.5 GPa inner pressure was constructed. Four paths were defined to investigate the stress state at the bottom comer of the die where stress concentration was serious. FEA results show that the change of parting face from non-plane to plane can greatly reduce the stress at the teeth tips of the die so that the tip fracture is avoided. The interference structure of the die is the most important influencing factor for the stress concentration at the bottom comer. When non-uniform interference is adopted the first principal stress at the comer on the defined paths of the die is much lower than that with uniform interference. The bottom hole radius is another important influencing factor for the comer stress concentration. The first principal stress at the comer of the plane parting face die with non-uniform interference is reduced from 2.3 to 1.9 GPa when the hole radius increases from 12.5 to 16.0 mm. The optimization of the die structure increases the life of the die from 100 to 6 000 hits.

关键词： die gear precision forging finite element analysis optimized design

Improved design and test of flexible cotton stalks puller

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International Journal of Agricultural and Biological Engineering 2023年第3期16卷 78-84页

作者： Jialin Cai Jiaxi Zhang Gang Guo Zebin Gao Xiaoxuan Wang College of Mechanical and Electrical Engineering Xinjiang Agricultural UniversityUrumqi 830052China

In Xinjiang,in the process of whole stalk harvesting of cotton stalks,there is a problem that the cotton stalks are easily pulled off,and there is an urgent need to develop flexible stalk-pulling *** literature,patent summary,and field research,it is found that domestic researchers have designed many kinds of machines for the problem of easy breaking of cotton stalks,but there is no flexible cotton stalk-pulling machine for the time *** this study,two flexible cotton stalk-pulling machines were intended to address the problem of easy breakage of cotton *** the basis of the first-generation machine,the design of the second-generation machine was *** order to further improve the operational performance of the flexible cotton stalks pulling tools,the operational mechanism of the core working parts of the tools was analyzed and a comparative test was done in a large *** and the comparative tests proved that improving the clamping working stroke s of the stalk-pulling components can effectively reduce the cotton stalks leakage *** using a flexible clamping process,a part of the deformation of cotton stalks can be transferred to the flexible *** a certain extent,the deformation length L of the contact surface between the cotton stalk and the stalk pulling part is reduced,and the deformation displacementΔy is correspondingly *** toughness of the cotton stalk is not significantly decreased and the cotton stalk does not break *** improved second-generation machine has a 3.67% to 3.79% lower cotton stalks leakage rate and a 5.65% to 6.30% lower cotton stalks breakage rate than the first-generation *** the land in Xinjiang is clay soil,soil bonding to cotton stalks pulling force F2 is larger,resulting in cotton stalks being more difficult to be pulled out of the machine at *** test proved that the improved second-generation implements had a significant improvement in the cotton stalk-pulling effect

关键词： agricultural machinery flexible material optimized design verification test cotton stalks puller

Series design of Large-Scale NC Machine Tool

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Journal of China University of Mining and Technology 2007年第2期17卷 272-276页

作者： TANG Zhi Engineering and Mechanical Institute Donghua University Shanghai 201620 China

Product system design is a mature concept in western developed countries. It has been applied in war industry during the last century. However,up until now,functional combination is still the main method for product system de-sign in China. Therefore,in terms of a concept of product generation and product interaction we are in a weak position compared with the requirements of global markets. Today,the idea of serial product design has attracted much attention in the design field and the definition of product generation as well as its parameters has already become the standard in serial product designs. Although the design of a large-scale NC machine tool is complicated,it can be further optimized by the precise exercise of object design by placing the concept of platform establishment firmly into serial product de-sign. The essence of a serial product design has been demonstrated by the design process of a large-scale NC machine tool.

关键词： large-scale NC machine tool series product design optimized design

Making Effective Decisions in Computer Architects' Real-World:Lessons and Experiences with Godson-2 Processor designs

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Journal of Computer Science & Technology 2008年第4期23卷 620-632页

作者：胡伟武王剑 Institute of Computing Technology Chinese Academy of Sciences

Although the design of many kinds of microprocessors has been under developing for several decades, the computer architecture R＆D community lacks well documented lessons and experiences about design decisions in the research literature. In this paper, we systematically present the design decisions we made during the designing and prototyping of Godson-2 series processors. The 250MHz Godson-2B, 450MHz Godson-2C, and 1GHz Godson-2E processors that implement 64-bit, four-issue, out-of-order architecture were taped out in 2003, 2004, and 2005, respectively. Each processor triples its predecessor in the SPEC CPU2000 rates. Our first-hand experiences and lessons gained from these designs would provide unique perspectives and insights that are not available in any existing text books and/or published papers. We summarize 10 critical lessons and experiences based on hundreds of our attempts at architectural and design optimizations for performance improvement of Godson-2 series processors. The issues include silicon-simulation correlation, design balancing, performance optimizing, and pico-architecture tuning. We conclude that persistent improvement, attitude towards work-on-silicon design, and insightful understanding of software and fabrication process are the three most important factors for designing a high performance processor with low energy consumption.

关键词： superscalar architecture correlation design balanced design optimized design Pico-architecture design work-on-silicon

optimized damping for LCL filters in three-phase voltage source inverters coupled by power grid

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Journal of Modern Power Systems and Clean Energy 2017年第4期5卷 642-651页

作者： Meng HUANG Jianjun SUN Yu PENG Xiaoming ZHA Wuhan University WuhanChina Wuhan Electric Power Technical College WuhanChina

The application of LCL filters has become popular for inverters connected to the power grid due to their advantages in harmonic current reductions. However,the power grid in a distribution system is non-ideal, presenting itself as a voltage source with significant impedance. This means that an inverter using an LCL filter may interact with other grid-connected inverters via the nonideal grid. In this paper, damping optimization of LCLfilters to reduce this interaction is studied for a three-phase voltage source inverter(VSI). Simulation results show that resonant oscillation occurs in a distributed power grid, even if the VSI with an LCL filter is well designed for standalone applications. A small-signal analysis is performed to predict this stability problem and to locate the boundary of the instability using an impedance approach. Based on these analytical results, optimized damping of the LCLfilter can be designed. The oscillation phenomena and optimized damping design are verified by simulations and experimental measurements.

关键词： LCL filter Three-phase voltage source inverter Non-ideal power grid optimized design Interacting converters

A new anchor-siphon drainage combined method used for slope stabilization

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Journal of Mountain Science 2023年第11期20卷 3295-3311页

作者： SUN Hong-yue WANG Xu YU Yang SHU Jun-wei WANG Tian-long LUO Rui CHU Zhao-wei Ocean College Zhejiang UniversityZhejiang ProvinceZhoushan 316021China College of Civil Engineering and Architecture Zhejiang UniversityHangzhou 310058China

A new anchor-siphon drainage combined method used for slope stabilization is proposed in this *** includes an anchoring section and a siphon drainage *** novelty of the anchor-siphon drainage combined method is the realization of the drainage and anchoring in the one inclined *** engineering cost of drilling and the resulting disturbance to the slope is *** validate the feasibility of the proposed method,a numerical method that combines the pore water pressure distribution after siphon drainage and the anchoring force of the anchoring section is used to evaluate the safety of the slope with the anchor-siphon drainage *** proposed method was illustrated and validated with the Hongpu Village landslide,in Tonglu County,Zhejiang Province,in *** with the common anchor bar with the same length in the anchoring section,the factor of safety(FOS)for Hongpu Village slope with anchorsiphon drainage is increased by *** calculation method of the optimal length ratio between the drainage section and the anchoring section and its influencing factors were *** the different design parameters,there is always an optimal length ratio of the drainage *** with the siphon drainage and full-length anchor bar with the same borehole length,the anchor-siphon drainage combined method shows better landslide prevention ***,when the optimized parameters with a bond strength of 560kPa,a borehole inclination of 35°,and no reduction in length are used,the calculated safety factor is 1.316,which is significantly higher than the FOS of 1.131 for the slope with siphon drainage.

关键词： Landslide Safety factor optimized design Siphon drainage Anchor New structure

Optimization of DC Resistance Divider Up to 1200 kV Using Thermal and Electric Field Analysis

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Energy Engineering 2023年第11期120卷 2611-2628页

作者： Dengyun Li Baiwen Du Kai Zhu Jicheng Yu Siyuan Liang Changxi Yue Department of Metrology China Electric Power Research InstituteWuhan430074China

Self-heating and electric field distribution are the primary factors affecting the accuracy of the Ultra High Voltage Direct Current(UHVDC)resistive *** the internal temperature rise of the voltage divider caused by self-heating,reducing the maximum electric field strength of the voltage divider,and uniform electric field distribution can effectively improve the UHVDC resistive divider’s *** this paper,thermal analysis and electric field distribution optimization design of 1200 kV UHVDC resistive divider are carried out:(1)Using the proposed iterative algorithm,the heat dissipation and temperature distribution of the high voltage DC resistive divider are studied,and the influence of the ambient temperature and the power of the divider on the temperature of the insulating medium of the divider is analyzed;(2)Established the finite element models of 1200 kV and 2×600 kV DC resistive dividers,analyzed the influence of the size of the grading ring and the installation position on the maximum electric field strength of the voltage divider,and calculated the impact of the shielding resistor layer on the vicinity of the measuring resistor *** research indicates that:(1)The temperature of the insulating medium is linearly related to the horsepower of the voltage divider and the ambient temperature;(2)After the optimized design of the electric field,the maximum electric field strength of the 1200 kV DC resistive divider is reduced to 1471 V/mm,which is about 24% lower than that of the unoptimized design;(3)Installing the shielding resistor layer can significantly improve the electric field near the measuring resistor *** paper has an important reference function for improving the accuracy of the UHVDC resistive divider.

关键词： DC voltage divider heat transfer electric field grading ring shielding resistor layer optimized design

Steam Flooding after Steam Soak in Heavy Oil Reservoirs through Extended-reach Horizontal Wells

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Petroleum Science 2007年第2期4卷 71-74页

作者： Ning Zhengfu Liu Huiqing Zhang Hongling Department of Science and Technology China University of Petroleum Beijing 102249 China MOE Key Laboratory of Petroleum Engineering China University of Petroleum Beijing 102249 China

This paper presents a new development scheme of simultaneous injection and production in a single horizontal well drilled for developing small block reservoirs or offshore reservoirs. It is possible to set special packers within the long completion horizontal interval to establish an injection zone and a production zone. This method can also be used in steam flooding after steam soak through a horizontal well. Simulation results showed that it was desirable to start steam flooding after six steam soaking cycles and at this time the oil/steam ratio was 0.25 and oil recovery efficiency was 23.48%. Steam flooding performance was affected by separation interval and steam injection rate. Reservoir numerical simulation indicated that maximum oil recovery would be achieved at a separation section of 40-50 m at steam injection rate of 100-180 t/d; and the larger the steam injection rate, the greater the water cut and pressure difference between injection zone and production zone. A steam injection rate of 120 t/d was suitable for steam flooding under practical injection-production conditions. All the results could be useful for the guidance of steam flooding projects.

关键词： Heavy oil horizontal well steam soak steam flooding single well injection and production optimized design

Improved method and case study of ground-coupled heat pump system design

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Improved method and case study of ground-coupled heat pump s...