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Performance of elastic ball screen-cleaning device based on DEM-MBD coupling simulation

PARTICUOLOGY 2024年第10期93卷 247-263页

作者： Bi, Yubin Song, Qingbin Zhu, Jingyu Feng, Jintao dong, jianxin Zhao, Pengfei Huang, Yuxiang Fu, Zuoli Zhou, Jixing Northwest A&F Univ Coll Mech & Elect Engn Yangling 712100 Peoples R China Shaanxi Engn Res Ctr Agr Equipment Yangling 712100 Peoples R China Henan Napu Biotechnol Co Ltd Zhengzhou 450000 Peoples R China

In seed breeding, the vibrating screen used for pre-sowing grading parental seeds often has the problem of poor self-purification rate. Using elastic balls to clean the plugging seeds and ensure the selfpurification of the screen is a viable technical solution. To clarify and improve the operating performance of the elastic ball particles, a DEM-MBD coupling simulation model of the elastic ball screencleaning device was established in this study, and a numerical simulation analysis of the complex motion process was carried out. The mechanism of action of the elastic ball was explained more completely from the aspects of excitation force and energy transfer. Through the Plackett-Burman test, it was determined that the vibration frequency has the most significant effect on the excitation force. Multiple linear regression analysis was performed on each factor and the mathematical relationship equation. It was found that when the maximum excitation force was greater than 7 N and the average excitation force was greater than 2 N, the self-purification rate was greater than 95%. The self-purification rate was then increased to 99.81% by variable frequency tests. The variable frequency achieved better selfpurification effect. (c) 2024 Chinese Society of Particuology and Institute of Process Engineering, Chinese Academy of Sciences. Published by Elsevier B.V. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

关键词： Seed breeding Grading Vibrating screen Self-purification Coupling simulation Variable frequency AGRICULTURAL PARTICLES DISCRETE SEPARATION DESIGN FLOW EFFICIENCY KINEMATICS

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碳化物特征对GH3536合金冷变形损伤的影响及控制

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金属学报 2024年第4期60卷 464-472页

作者：余华李昕江河姚志浩董建新北京科技大学材料科学与工程学院北京100083

为了研究碳化物对GH3536合金冷变形损伤的影响并加以控制,通过薄带材的冷轧变形和圆柱试样的压缩变形,观察了碳化物破裂以及基体局部开裂的现象,并结合有限元模拟结果,进一步探讨了碳化物形貌与分布特征对组织损伤的影响。结果表明,当... 详细信息

为了研究碳化物对GH3536合金冷变形损伤的影响并加以控制,通过薄带材的冷轧变形和圆柱试样的压缩变形,观察了碳化物破裂以及基体局部开裂的现象,并结合有限元模拟结果,进一步探讨了碳化物形貌与分布特征对组织损伤的影响。结果表明,当碳化物尺寸较大、形状不规则且呈团聚分布时,其内部应力与破裂倾向较大,而小尺寸圆形碳化物的情况与之相反。碳化物的团聚与条带状分布是引起基体应力和开裂倾向增加的主要原因。热处理结果表明,通过将热处理温度提高到1150℃以上,可以明显改善小尺寸碳化物的团聚和条带状分布特征,但对于10μm以上的大尺寸碳化物改善效果不明显。

关键词： GH3536合金冷变形热处理碳化物破裂

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玉米亲本种子变幅振动式分级装置研制

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农业工程学报 2024年第12期40卷 23-32页

作者：毕于彬宋庆斌赵鹏飞董建鑫黄玉祥付作立周济兴西北农林科技大学机械与电子工程学院杨凌712100 陕西省农业装备工程研究中心杨凌712100 郑州度风科技有限公司郑州450000

针对玉米繁种阶段亲本种子播前分级效率低、筛面自净效果差的问题,该研究提出一种变幅振动筛分方法,并设计了种子分级振动筛装置,对驱动机构和自净清筛装置进行设计与分析。在喂入量2.5 kg/s的条件下,以京科968玉米种子为试验对象,以分... 详细信息

针对玉米繁种阶段亲本种子播前分级效率低、筛面自净效果差的问题,该研究提出一种变幅振动筛分方法,并设计了种子分级振动筛装置,对驱动机构和自净清筛装置进行设计与分析。在喂入量2.5 kg/s的条件下,以京科968玉米种子为试验对象,以分级合格率、作业时间和卡种数量为试验指标,通过四因素(进料口高度、振幅、振动频率和筛面倾角)三水平Box-Behnken试验,建立各因素与试验指标间的回归模型,并对参数进行优化。结果表明,影响变幅振动式分级装置分级合格率的主次因素顺序为振动频率、筛面倾角、振幅和进料口高度,影响作业时间的主次因素顺序为振动频率、振幅、筛面倾角和进料口高度;卡种数量具有较大的随机性,当振幅和振动频率都较低时,筛面卡种数量急剧增多,自净效果极差。最优参数组合为进料口高度19 mm、振幅5 mm、振动频率8.25 Hz、筛面倾角7°,模型优化预测结果为分级合格率88.04%,作业时间40 s。在最优条件下的验证试验结果为分级合格率89.55%、作业时间39 s,平均卡种数量8粒,与预测结果基本一致,较等幅振动式分级装置的分级合格率提高3.25个百分点,作业时间减少4 s,平均卡种数量减少2粒,作业性能优于等幅振动式分级装置。分级装置分级效率达0.33 t/h,各项指标均满足相关设计要求。研究结果可为繁种阶段种子分级装备的设计提供参考。

关键词：农业机械种子分级振动筛玉米

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Microsegregation and Rayleigh number variation during the solidification of superalloy Inconel 718

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Journal of University of Science and Technology Beijing 2008年第5期15卷 594-599页

作者： Ling Wang jianxin dong Yuliang Tian Lei Zhang School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China College of Mathematics and Physics Nanjing University of Information Science and Technology Nanjing 210044 China

The microstructure and composition of the residual liquid at different temperatures were investigated by scanning electron microscopy （SEM） and energy dispersive X-ray spectrometer （EDX） associated with the Thermo-calc software calculation of the equilibrium phase diagrams of Inconel 718 and segregated liquid. The liquid density difference and Rayleigh number variation during solidification were estimated as well. It is found that the heavy segregation of Nb in liquid prompts the precipitation of δ and Laves phase directly from liquid and the resultant quenched liquid microstructure consists of pro-eutectic γ＋eutectic,or complete eutectic according to the content of Nb from low to high. The liquid density increases with decreasing temperature during the solidification of Inconel 718 and the liquid density difference is positive. The largest relative Rayleigh number occurs at 1320°C when the liquid fraction is about 40vol%.

关键词： superalloy Inconel 718 microsegregation liquid density difference Rayleigh number

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Phenomenon and Mechanism of High Temperature Low Plasticity in High-Cr Nickel-based Superalloy

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Journal of Materials Science & Technology 2013年第2期29卷 187-192页

作者： Zhongnan Bi jianxin dong Lei Zheng Xishan Xie University of Science and Technology Beijing Beijing Key Laboratory of Advanced High Temperature Materials Central Iron and Steel Research Institute

Cr is the most important element in nickel-based alloys to prevent high temperature oxidation and corrosion. However, high-Cr content will lead to a decline of hot workability which limits the addition of Cr for most nickel-based superalloys. In order to add more Cr into Ni-based alloy for improving high temperature oxidation and corrosion resistance, the poor hot workability of high-Cr alloy must be first solved. Deformation characteristic of a high-Cr nickel-based alloy （40 wt% Cr） under hot compression conditions at 800-1200 ℃ has been investigated by using a Gleeble 3500 machine, and the microstructural evolution during hot working process has been observed by optical microscopy and scanning electron microscopy. The results show that a high-temperature low-plasticity （HTLP） region exists in this high-Cr nickel-based alloy. This phenomenon can be attributed to its non-uniform interdendritic microstructure at high temperatures. These results can explain the poor hot workability of high-Cr nickel-based alloy.

关键词： High-Cr nickel-based superaUoy Hot workability Forging α-Cr phase High temperature low plasticity

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镍基高温合金中S元素对基体与热障涂层界面稳定性的影响

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金属学报 2024年第9期60卷 1250-1264页

作者：王京京姚志浩张鹏赵杰张迈王蕾董建新陈迎北京科技大学材料科学与工程学院北京100083 北京科技大学物理系北京100083 Fracture and Reliability Research Institute Tohoku University6-6-11 Aramakiaza-AobaAoba-kuSendai 980-8579Japan

镍基高温合金中的S元素会对合金性能产生负面影响,在服役过程中含S体系的界面处会发生氧化膜剥落等现象,进而导致合金发生失效。本工作利用第一性原理计算,围绕S元素在镍基高温合金及其涂层的偏聚现象,研究了S元素对合金及NiAl涂层的影... 详细信息

镍基高温合金中的S元素会对合金性能产生负面影响,在服役过程中含S体系的界面处会发生氧化膜剥落等现象,进而导致合金发生失效。本工作利用第一性原理计算,围绕S元素在镍基高温合金及其涂层的偏聚现象,研究了S元素对合金及NiAl涂层的影响机制。分析了Ni_(3)Al/NiAl、NiAl/Al_(2)O_(3)的纯净界面和含S元素界面2种模型的界面黏附功、偏聚能及界面电荷情况。结果表明,合金中含S元素的体系界面黏附功变小,进而降低了界面稳定性;S元素在各自的体系内均有向界面偏聚的倾向。通过分析其界面电子结构(如二次差分电荷密度、Bader电荷、局域电子密度、态密度等)的演变,发现S元素的存在会减弱界面附近的键合,进而降低局部连接的紧密性。最后揭示了S元素对体系界面稳定性的影响机制。

关键词：镍基高温合金 S元素界面体系电子结构第一性原理计算

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基于实体交互的老幼共娱产品设计研究

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设计 2024年第8期37卷 48-51页

作者：张路董建昕张济时大连理工大学建筑与艺术学院

充分研究老年人和儿童这两类人群对老幼共娱产品的需求,利用实体交互理论指导老幼共娱产品设计研究,训练用户的认知能力,促进老幼两代之间的情感交流。本文以实体交互理论为指导,综合运用文献分析法、问卷调查法、用户访谈法、观察法等... 详细信息

充分研究老年人和儿童这两类人群对老幼共娱产品的需求,利用实体交互理论指导老幼共娱产品设计研究,训练用户的认知能力,促进老幼两代之间的情感交流。本文以实体交互理论为指导,综合运用文献分析法、问卷调查法、用户访谈法、观察法等,对老幼互动行为、实体交互介入老幼共娱产品的设计策略进行了着重研究。结合实体交互理论,提出了以讲述中国传统故事为主题,积木为实体产品,平板电脑为移动终端的老幼共娱产品设计策略。为当代城市隔代教育家庭出现的现实问题提供全新的解决途径。

关键词：实体交互隔代教育老幼共娱 KANO模型产品设计

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Microstructure-based hot extrusion process control principles for nickel-base superalloy pipes

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Progress in Natural Science:Materials International 2018年第3期28卷 391-398页

作者： He Jiang Linhan Li jianxin dong Xishan Xie School of Materials Science and Engineering University of Science and Technology Beijing

The properties of nickel-base superalloy pipes are determined by microstructure, and the microstructure can be tuned by hot extrusion process. There are two major questions in hot extrusion: one is how to successfully extrude pipes without apparent defects, the other is how to make the microstructure under control. However, up to now, there is no systematical report about hot extrusion process and microstructure control for nickel-base superalloys. In present study, a series of technical control principles for hot extrusion are proposed basing on practical manufacture facts, large amounts of experimental studies and finite element simulation of several typical nickel-base superalloys. The common used technical control principles can be applied for hot extrusion parameters determination to maintain safety hot extrusion and microstructure control. In the investigation of microstructure control based hot extrusion principles, the action rules of different working parameters on hot extrusion field quantities were established. The upper and lower limits of different principles were obtained in consideration of materials characteristics and extruder conditions. The limitations were overlapped on the action rules to determine the optimized hot extrusion parameters. The microstructure-based control principle proposed in present work can provide theoretical guidance for hot extrusion parameter determination and optimization.

关键词： Nickel-base superalloy Hot extrusion Microstructure evolution Control principle

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Constitutive relationship of IN690 superalloy by using uniaxial compression tests

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Rare Metals 2011年第1期30卷 81-86页

作者： SUN Chaoyang LIU Jinrong LI Rui ZHANG Qingdong dong jianxin School of Mechanical Engineering University of Science and Technology Beijing Beijing 100083China School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China

The hot deformation behavior of IN690 superalloy was characterized in a temperature range of 1273-1473 K and a strain rate range of 0.01-10 s^-1 using uniaxial compression tests on process annealed *** constitutive relations between flow stress and effective strain,effective strain rate as well as deformation temperature were *** can be concluded that the flow stress significantly reduces with the deformation temperature of IN690 superalloy ***,there is a significant increase of flow stress when the strain rate increases from 0.1 s^-1 to 10 s^-*** on the hyperbolic-sine Arrhenius-type equation,a constitutive equation considering compensation of strain was *** activation energy and the material constants（Q,n and ln A） decrease as the deformation strain *** strain dependent term is successfully incorporated in the constitutive equation through a quartic equation.A good agreement between the experimental data and the predicted results has been achieved,indicating that the proposed constitutive equation and the methods of determing the material constants are suitable to model the high temperature deformation behavior of IN690 superalloy.

关键词： superalloys compression testing constitutive equations activation energy

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Crack initiation and propagation induced by inclusions in a nickel-base P/M superalloy under fatigue load

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Rare Metals 2005年第3期24卷 298-300页

作者： ZENG Yanping ZHANG Maicang dong jianxin ZHANG Lina XIE Xishan High Temperature Materials Research Laboratory University of Science and Technology Beijing Beijing 100083 China School of Materials Science and Engineering Tsinghua University Beijing 100084 China

In situ fatigue tests in special designed SEM were conducted to trace the whole process of crack initiation and propagation fill to fracture in mckel-base P/M superalloy seeded inclusions. The experimental results show that non-metallic inclusions can induce crack initiation. When the inclusion size is larger than the critical one, the crack can propagate as the main crack that induces the specimen to fracture. As a result, the LCF life of the specimen decreases.

关键词： nickel-base P/M superalloy inclusion crack initiation and propagation fracture

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