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Research of The Influence Mechanism of Multi Gradient Printing on Sand Mold Performance

Journal of Physics: Conference Series 2021年第1期1965卷

作者： LI Zheng Shan Zhongde Liu Feng Ran Yuelong State Key Laboratory of Advanced Forming Technology and Equipment Beijing National Innovation Institute of Lightweight Ltd. Beijing 100044 China Nanjing University of Aeronautics and Astronautics Nan jing 211106 China

In this paper, multi gradient sand mold sample printing was carried out based on the gray printing technology of sand mold 3D printing, and the influence of gradient distribution of resin addition in sand mold on the property of sand mold was studied. The results showed that the increase of resin addition gradient in sand mold would result in the decrease of tensile strength of sand mold with the constant total resin addition. The bending strength and air permeability of sand mold were mainly affected by the surface resin addition and gradient distribution. With increase of surface resin addition, The bending strength of sand mold decreased, and of which the air permeability increased at the same time. And the increase of gradient spacing between adjacent resin addition gradients in sand mold would lead to the increase of sand mold air permeability and the decrease of tensile strength and bending strength. The result also showed that The surface hardness of the sand mold increased with the increase of the resin content of the surface layer, and had nothing to do with the gradient distribution of the resin content.

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Reliability evaluation of bladder accumulator with no failure data

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High technology Letters 2018年第3期24卷 322-329页

作者：郭锐 Zhang Rongbing Zhao Jingyi Zhou Jinsheng Zhang Zhenmiao Hebei Provincial Key Laboratory of Heavy Machinery Fluid Power Transmission and Control Yanshan UniversityKey Laboratory of Advanced Forging & Stamping Technology and Science (Yanshan University) College of Mechanical Engineering (Yanshan University) Qinhuangdao YSU -Yihua Electrical and Mechanical Engineering Technology Research Institute Co. Ltd.

As a bladder accumulator is a high reliable and long life component in a hydraulic system,its cost is high and it takes a lot of time to test its reliability,therefore,a reliability test with small sample is performed,and no failure data is obtained using the method of fixed time truncation. In the case of Weibull distribution,a life reliability model of bladder energy storage is established by Bayesian method using the optimal confidence intervals method,a model of one-sided lower confidence intervals of the reliability and one-sided lower confidence intervals model of the reliability life are established. Results of experiments show that the evaluation method of no failure data under Weibull distribution is a good way to evaluate the reliability of the accumulator,which is convenient for engineering application,and the reliability of the accumulator has theoretical and practical significance.

关键词： bladder accumulator Weibull distribution fixed time truncation no failure data reliability assessment

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Type Synthesis of Ring Truss Deployable Antenna Mechanism Based on Screw Theory

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Yuhang Xuebao/Journal of Astronautics 2019年第7期40卷 831-841页

作者： Han, Bo Xu, Yun-Dou Han, Yuan-Yuan Yao, Jian-Tao Zhao, Yong-Sheng Parallel Robot and Mechatronic System Laboratory of Hebei Province Yanshan University Qinhuangdao066004 China Key Laboratory of Advanced Forging & Stamping Technology and Science of Ministry of Education Yanshan University Qinhuangdao066004 China Department of Mathematics and Computer Science Hengshui University Hengshui053000 China

Based on the screw theory, the type synthesis of the ring truss deployable antenna mechanism is studied. Firstly, the constrained synthesis method based on the screw theory is briefly introduced, and the deployment principle of the ring truss deployable antenna mechanism is analyzed. Then, the ring truss mechanism is divided into two parts, the upper ring edge and the lower ring edge, the ring truss mechanism can be obtained by constructing the ring edge mechanisms and connecting the upper and lower ring edges. Furthermore, the prismatic joint (P) ARE used to describe the movement characteristics of each node, the analysis and synthesis of the ring edge mechanisms are carried out by the constraint synthesis method based on the screw theory, 16 kinds of constraint branch mechanisms are obtained, and two kinds of constraint branch mechanisms are selected through analysis and optimization. The ring edge link mechanisms are obtained by combining the constraint branch mechanisms, and four ring truss deployable mechanisms are obtained through different connection combinations. Finally, three-dimensional models are built in Solidworks software for the four kinds of ring truss deployable mechanisms, and the deployable features of the four mechanisms are verified by the movement simulation. The research provides a new idea for the synthesis of the deployable antenna mechanisms, and the ring truss mechanisms obtained have a good application prospect in the field of space deployable antenna. © 2019, Editorial Dept. of JA. All right reserved.

关键词： Computer software

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Recurrence Plot Quantitative Analysis-Based Fault Recognition Method of Rolling Bearing

Recurrence Plot Quantitative Analysis-Based Fault Recognitio...

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Prognostics and System Health Management Conference (PHM-Qingdao)

作者： Wanlu Jiang Zhenbao Li Anqi Jiang Yafei Lei Haonan Wang Hebei Provincial Key Laboratory of Heavy Machinery Fluid Power Transmission and Control Yanshan University Qinhuangdao China Key Laboratory of Advanced Forging & Stamping Technology and Science (Yanshan University) Ministry of Education of China Qinhuangdao China

Aiming at the problem that rolling bearings are widely used but have high failure rate. A fault diagnosis method combined with local projective noise reduction method and recurrence plots quantification analysis for rolling bearings is presented. The fault vibration signals of rolling bearings are taken as the analysis objects. Firstly, the vibration signal is denoised by local projective noise reduction method. Then, the recurrence plots of denoised vibration signals are drawn. The system dynamic behavior reflected in the recurrence plots is extracted by recurrence quantification analysis. The determinism (DET) and entropy (ENTR) are selected to form the characteristic vectors. Finally, the characteristic vectors of the training samples are clustered by kernel fuzzy C-means (KFCM) clustering method. The minimum Euclidean distance principle is used to identify the test samples. Comparing the recurrence plot quantification analysis method with the quantitative feature method of phase space complex network. The results show that the recurrence plots quantification analysis-based fault diagnosis method of rolling bearings has a higher diagnosis rate.

关键词： Time series analysis Rolling bearings Complex networks Noise reduction Fault diagnosis Kernel Machinery

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Study on forming technology of Composite Micro-wire Made From AF and PLA

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Journal of Physics: Conference Series 2021年第1期1986卷

作者： ZOU Ailing SHAN Zhongde CHEN Yiwei WANG Shaozong LIU Xiaojun State Key Laboratory of Advanced Forming Technology and Equipment of China Academy of Machinery Science and Technology Beijing China Beijing National Innovation Institute of Lightweight ltd. Beijing China Nanjing University of Aeronautics and Astronautics Nanjing China

In order to improve the interlaminar shear property of the composites manufactured by the additive of aramid fiber (AF) reinforced with polylactic acid (PLA), the preparation process of AF reinforced thermoplastic resin composite micro-wires has been optimized, which could promote impregnated and toughness. The influence of different water bath temperatures on the interlaminar shear properties of the composites was studied. And the results showed that the largest interlaminar shear strength (ILSS) of AF/PLA composite material was 12.0 MPa, which had confirmed in the water bath temperature of 30°C. As the bath temperature increased, the interlaminar shear performance decreased, and the ILSS of composite micro-wires in 70°C water bath was 74.67% of that in 30°C water bath. The composite fiber with high impregnation degree and good toughness has laid a foundation for further research on additive manufacturing of AF/PLA composite.

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Dynamics Parameter Identification and Control of a Spherical 2-DOF Redundant Driven Parallel Robot System

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Zhongguo Jixie Gongcheng/China Mechanical Engineering 2019年第16期30卷 1967-1975页

作者： Li, Yongquan Wu, Pengtao Zhang, Yang Zhang, Lijie Parallel Robot and Mechatronic System Laboratory of Hebei Province Yanshan University QinhuangdaoHebei066004 China Key Laboratory of Advanced Forging & Stamping Technology and Science Ministry of Education Yanshan University QinhuangdaoHebei066004 China Hebei Provincial Key Laboratory of Heavy Machinery Fluid Power Transmission and Control Yanshan University QinhuangdaoHebei066004 China

A spherical 2-DOF redundant drive parallel robot driven by servo motor was the research ***, the inertia parameter identification model of the mechanisms was established, and the inertial parameter identification trajectory was ***, the friction parameter identification model of the mechanism pairs and the friction parameter identification model of the driving system were established, and their identification principles were analyzed *** trajectory of friction parameter identification was also ***, through the identification experiments, the mechanism inertia parameters, the mechanism rotation pair friction parameters and the driving system friction parameter identification results were obtained, the original mechanism parameters were modified by the identification results, a more accurate robot system dynamics model was obtained, and the identification results were validated by the trajectory test ***, a feed forward control strategy was developed based on the dynamics model of the robot system and compared with the traditional mechanism kinematics closed-loop control *** feasibility of this control strategy was proved. © 2019, China Mechanical Engineering Magazine Office. All right reserved.

关键词： Mechanisms

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Characterization of spherical AlSi10Mg powder produced by double-nozzle gas atomization using different parameters

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Transactions of Nonferrous Metals Society of China 2019年第2期29卷 374-384页

作者： Chao-feng GAO Zhi-yu XIAO Hai-ping ZOU Zhong-qiang LIU Jin CHEN Shang-kui LI Da-tong ZHANG National Engineering Research Center of Near-Net Shape Forming for Metallic Materials South China University of TechnologyGuangzhou 510640China Guangdong Provincial Key Laboratory for Processing and Forming of Advanced Metallic Materials South China University of TechnologyGuangzhou 510640China Jiangxi Yuean Superfine Metal Co. Ltd.Ganzhou 341000China Foshan Suizhibo Novel Materials Co. Ltd.Foshan 528000China

A self-developed double-nozzle gas atomization technique was used to produce AlSi10Mg *** of delivery tube diameter,gas pressure,and melt superheat on powder characteristics were *** concepts of bluntness and outgrowth were introduced to analyze powder sphericity and satellite index *** results showed that the median diameters of all atomized powders ranged from 25 to 33μ*** highest yield rate(72.13%)of fine powder(<50μm)was obtained at a superheat of 350 *** powder size decreased with increasing melt superheat but increased with increasing delivery tube *** with bluntness values between 96%and 98%accounted for over 60%.The outgrowth values demonstrated that 70%-85%of all powders did not contain satellite particles,with few powders adhered two or three *** only Al and Si phases were present but also a metastable Al9Si phase was detected.

关键词： gas atomization AlSi10Mg powder particle size particle shape bluntness outgrowth

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Design and Structure Simulation Analysis of Sand-mold Inkjet Printing Device

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Journal of Physics: Conference Series 2021年第5期1885卷

作者： Yifei Wang Zhongde Shan Shuangfeng Wu Zhi Guo Shijie Dong shan Hu State Key Laboratory of Advanced Forming Technology and Equipment Beijing 100083 China Beijing National Innovation Institute of Lightweight Ltd Beijing 100083 China College of Material science and Technology Nanjing University of Aeronautics and Astronautics Nanjing 210016 China

Ink-jet printing technology is a digital high-efficiency forming technology that can realize the rapid manufacturing of sand mold for foundry. This paper designs a low-cost, high-reliability ink-jet printing device based on the sand-mold inkjet printing process, and uses ANSYS finite element analysis software to carry out static analysis and modal analysis for its main frame. The analysis results show that the main frame has good rigidity and high strength, there will be no large deformation and resonance in frame under the working conditions, which can meet the requirements of sand-type inkjet printing devices.

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Deployable antenna mechanism with class of modular truss based on tetrahedral combination unit

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Hangkong Xuebao/Acta Aeronautica et Astronautica Sinica 2020年第3期41卷 423219页

作者： Guo, Jinwei Huang, Zhirong Xu, Yundou Guo, Luyao Yao, Jiantao Zhao, Yongsheng Parallel Robot and Mechatronic System Laboratory of Hebei Province Yanshan University Qinhuangdao066004 China Xi'an710100 China Key Laboratory of Advanced Forging & Stamping Technology and Science of Ministry of National Education Yanshan University Qinhuangdao066004 China

To solve the complex structure, the low folding rate, and the large number of motion pairs of the existing tetrahedral-based truss antenna mechanism, a class of new modular deployable structure is proposed based on the 3RR-3RRR tetrahedral combination unit and the 3RR-3URU tetrahedral symmetric combination unit. The modular structure consisting of three combination units is selected as the analysis object. First, the composition of the modular structure and the axis arrangement of the Hook hinges are introduced in detail, and the number and property of the Degree of Freedom (DOF) of the combination unit itself are obtained by applying the idea of link-demolishing-equivalent-restoration, the screw theory and the G-K formula. Second, the motion simulation of the two modular structures is carried out by using Adams dynamics simulation software. The simulation results verified the correctness of the DOF analysis. The folding rate of the mechanism is characterized by the ratio of the space volume occupied by the mechanism when fully unfolding and fully folding. The folding rates of the existing non-modular mechanisms and modular mechanisms based on tetrahedral unit are calculated. Finally, the number of DOF and motion pairs, the folding rate of non-modular mechanisms and modular mechanisms are compared and analyzed. The analysis results show that the modular structure based on the 3RR-3URU tetrahedral symmetrical combination unit can achieve a large folding rate, and the number of degree of freedom and motion pairs are also relatively reduced. In addition, fewer types of links are use when forming large antennas. The research results provide a theoretical basis for the design and analysis of such modular truss deployable antenna structures. © 2020, Press of Chinese Journal of Aeronautics. All right reserved.

关键词： Trusses

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Hydraulic bulging process with axial feedings and strain field of U-shaped metal bellows

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Journal of Central South University 2018年第11期25卷 2712-2721页

作者： HAO Zeng-liang XI Chen-yang HUANG Zhi-heng ZHANG Chun-xiang LUO Jun-ting Education Ministry Key Laboratory of Advanced Forging&Stamping Technology and Science Yanshan UniversityQinhuangdao 066004China State Key Laboratory of Metastable Materials Science and Technology Yanshan UniversityQinhuangdao 066004China

Based on the traditional hydraulic bulging process,an improved hydraulic bulging process with axial feeding in the bulging process was *** finite element simulation and experiment of bellows formed by the traditional and improved hydraulic bulging processes were *** grid strain measurement system analysis results of strain and wall thickness distribution of the metal bellows,obtained from simulation and experiment,show that the maximum thinning rates of the wall thickness under the traditional and improved processes were 15%and 10%,*** the wall thickness distribution of the metal bellows formed with improved process was more *** strain values from the root to crown of the waveform increased ***,the strain values were smaller than those of traditional process due to the axial feeding of the improved process in bulging process.

关键词： hydraulic bulging process finite element simulation thinning rate of wall thickness grid strain measurement system

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