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

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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Deep drawing of cup shell by powder cavity flexible forming technology

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Journal of Central South University 2017年第4期24卷 766-772页

作者： XUE Ya-hong CHEN Ke FAN Cun-jie LUO Jun-ting Education Ministry Key Laboratory of Advanced Forging and Stamping Technology and Science Yanshan UniversityQinhuangdao 066004China State Key Laboratory of Metastable Materials Science and Technology Yanshan UniversityQinhuangdao 066004China

A forming method named powder cavity flexible forming was proposed. It is a forming technology which uses powder medium instead of rigid punch or die to form sheet metals. Cup shells were successfully obtained by this technology. The theoretical calculation equation of forming load was obtained through mechanical analysis and the stress state in cup shells was analyzed by finite element simulation. The results show that powder cavity flexible forming technology can improve the forming limit of sheet metal. Compared with rigid die forming process, the thickness reduction in the punch fillet area significantly decreases and the drawing ratio increases from 1.8 to 2.2. The thinning compressive stress in the bottom of cup shell emerges, which makes the bottom of the cup shell in three-dimensional stress state and the stress in punch fillet region decrease due to powder reaction force, which can effectively inhibit the sever thinning of the sheet and prevent the generation of fracture defects.

关键词： cup shell powder cavity flexible forming drawing finite element simulation

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High temperature stress–strain curves of MnS and their applications in finite element simulation

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Transactions of Nonferrous Metals Society of China 2018年第10期28卷 2082-2093页

作者： Miao JIN Lin-lin YU Xin-gang LIU Bao-feng GUO Key Laboratory of Advanced Forging&Stamping Technology and Science Ministry of EducationYanshan UniversityQinhuangdao 066004China School of Mechanical Engineering Yanshan UniversityQinhuangdao 066004China

A novel method for testing stress–strain curves of non-metallic materials was *** high temperature stress-strain curves of MnS were preliminarily obtained and corrected to account for the influence of *** the finite element method,the influence of deformation parameters on the deformation evolution of MnS inclusions was investigated based on the experimental reference *** corresponding physical experiment was designed for comparative *** results indicate that the experimental high-temperature deformation data of MnS are highly *** the process of matrix deformation,the shapes of MnS inclusions change from spherical to ellipsoidal and even to *** are some differences in the morphological deformation of MnS inclusions located at different *** the increase in the initial size of MnS inclusions,the risk of failing the inclusion-flaw inspection increases and the forging quality further deteriorates.

关键词： inclusion MnS stress-strain curve finite element method morphology

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Effects of structural parameters on hydraulic performance of flow regulator

Effects of structural parameters on hydraulic performance of...

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CSAA/IET International Conference on Aircraft Utility Systems, AUS 2018

作者： Li, Yong Zong, Xuemei Yuan, Xiaoming Zhao, Shiyi State Key Laboratory of Intelligent Manufacturing of Advanced Construction Machinery Jiangsu Xuzhou Construction Machinery Research Institute Xuzhou Construction Machinery Group Co. Ltd. Xuzhou China Hebei Key Laboratory of Heavy Machinery Fluid Power Transmission and Control Key Laboratory of Advanced Forging and Stamping Technology and Science Yanshan University Qinhuangdao Hebei China

ISBN: (纸本)9781785617911

In order to evaluate the hydraulic performance of a regulator, the pressure loss and the stabilization performance of the regulator installed in the fire water monitor were introduced. The effects of structures on a regulator were investigated by the structural model made in UG and the flow simulation conducted in ANSYS. The hydraulic performance of a star-shaped regulator was analyzed with different structure parameters, such as the blade number, axial length and rounded-corner. The effects of structure parameters on the regulator were revealed, based on which the hydraulic performance of the improved regulator with different blade numbers was analyzed. The results show that the improved regulator with two cross-sections in dislocation and six even-distributed blades has the better hydraulic performance. The preliminary experimental results show that the improved regulator can improve the jet range of a fire water monitor. © 2018 IET Conference Publications. All rights reserved.

关键词： Flow simulation

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Analysis on performance and test of a new type of ultra-high pressure pipe joint

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High technology Letters 2018年第2期24卷 203-207页

作者： Zhai Fugang Kong Xiangdong Sun Yugang Wang Zhong Hao Xiaobei College of Mechanical Engineering Yanshan University Qinhuangdao 066004 P. R. Chin Key Laboratory of Advanced Forging ＆ Stamping Technology and Science （Yanshan University） Ministry of Education of China Qinhuangdao 066004 P. R. Chin Huaye Power Technology Co. Foshan 528300 P. R. China

Analysis as well as application of ultra-high pressure hydraulic system and elements has become a trend. The structure and operation principle of a new type of ultra-high pressure pipe joint is introduced. The structure of the new type of ultra-high pressure pipe joint is simple and is easy to be produced. The finite element model on two working conditions( preload condition with 30 N·m torque and static-loading condition with 70 MPa pressure) is built and computed. The width of contact area,the equivalent stress status,as well as the contact pressure status are plotted and analyzed. According to the national standard,test on air-tightness,blasting,and cyclic endurance is conducted and the results show that the new type of ultra-high pressure pipe joint has the sealability for ultra-high pressure up to 70 MPa,and the DN6 ultra-high pressure pipe joint can provide effective seal under70 MPa fluid pressure. The research can provide a thinking and method on designing ultra-high pressure pipe joint and push forward the development of ultra-high pressure hydraulic system.

关键词： pipe joint ultra-high pressure sealing performance hydraulic system

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Model-based Synchronous Control of Redundantly Actuated Parallel Manipulator with Neural Network

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Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery 2018年第2期49卷 367-375页

作者： Liu, Xiaofei Yao, Jiantao Zhao, Yongsheng Key Laboratory of Advanced Forging and Stamping Technology and Science Ministry of Education Yanshan University Qinhuangdao066004 China Key Laboratory of Parallel Robot and Mechatronic System of Hebei Province Yanshan University Qinhuangdao066004 China

Redundantly actuated parallel manipulator demands higher actuation coordination than the non-redundantly actuated one, thanks to its degree of actuation exceeding its degree of freedom. To improve the actuation coordination of redundantly actuated parallel manipulator, a novel model-based driving force synchronous control method with neural network was proposed. With 6PUS+UPU parallel manipulator as object, dynamic model was derived based on virtual work principle. To improve the actuation coordination of redundantly actuated parallel manipulator, a novel driving force synchronous control method was proposed on basis of force-position hybrid actuation. The synchronous control method was based on the driving force error of actuated joints and driving force adjustment was calculated by the synchronous controller. The synchronous controller was designed with neural network. What's more, the learning law of neural network controller was derived with manipulator's dynamic model to improve the learning efficiency. Model simulation and prototype experiment were carried out, and a performance comparison analysis with traditional force-position hybrid actuation method was made to verify the proposed control method. Comparison analysis revealed that, comparing with the traditional force-position hybrid actuation method, driving force synchronous control with neural network proposed could effectively improve the actuation coordination of redundantly actuated parallel manipulator. The results revealed that the synchronous control method reduced the driving force errors of whole manipulator by properly magnifying the control error of force actuated joint. © 2018, Chinese Society of Agricultural Machinery. All right reserved.

关键词： Dynamic models

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Driving force synchronous control of redundantly actuated parallel manipulator

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Jisuanji Jicheng Zhizao Xitong/Computer Integrated Manufacturing Systems, CIMS 2018年第9期24卷 2140-2149页

To improve the actuation coordination of redundantly actuated parallel manipulator, a novel model-based driving force synchronous control method was proposed. With 6PUS+UPU parallel manipulator as the research object, the dynamics model was deduced based on virtual work principle, and the coordination mechanism of driving force under scheduled motion was analyzed. On the basis of force-position hybrid actuation, a driving force synchronous control method was proposed, and the control algorithm was designed with coordination mechanism. Simulation and prototype experiment were used to verify the proposed control method. © 2018, Editorial Department of CIMS. All right reserved.

关键词： Manipulators

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Heat treatment and granule medium internal highpressure forming of AA6061 tube

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Journal of Central South University 2017年第5期24卷 1040-1049页

作者： BI Jiang ZHAO Chang-cai BI Meng-meng DU Bing CHEN Xiao-hua DONG Guo-jiang Key Laboratory of Advanced Forging&Stamping Technology and Science of Ministry of Education of China Yanshan UniversityQinhuangdao 066004China State Key Laboratory of Advanced Welding and Joining Harbin Institute of TechnologyHarbin 150001China College of Vehicles and Energy Yanshan UniversityQinhuangdao 066004China

The new forming process of AA6061 alloy tube, including solution treatment, granule medium internal high-pressure forming and aging treatment, was developed. The AA6061 alloy tube via heat treatment satisfied the forming requirement, and the granule medium internal high pressure forming method for AA6061 alloy tube was also realized by using convenient implementation with low requirement of equipment and flexible design of product. At a solution temperature of 560℃ and time of 120 min, the elongation of the AA6061 extruded tube increases by 300% and the strength and the hardness dramatically decrease too. Therefore, the AA6061 alloy tube meets the requirement of internal high-pressure forming because of the improvement of formability. The experiments shows that the strength and hardness of AA6061 alloy workpiece recover to that of the as-received alloy at an aging temperature of 180℃ and time of 360 min, and the strength of AA6061 alloy workpiece is equal to the base alloy. The typical parts of convex ring tube, stepped shaft tube and hexagonal tube were successfully produced in lab by using the present forming method. The forming tests show that the maximum expansion ratio(MER) of the AA6061 extruded tube increases by 25.5% and the material properties of formed AA6061 alloy tube reached the performance of as-received alloy.

关键词： aluminum alloy tube solution treatment aging treatment granule medium internal high pressure forming

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Embodied water analysis for Hebei Province, China by input-output modelling

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Frontiers of Earth science 2018年第1期12卷 72-85页

作者： Siyuan LIU Mengyao HAN Xudong WU Xiaofang WU Zhi LI Xiaohua XIA Xi JI Hebei Provincial Key Laboratory of Heavy Machinery Fluid Power Transmission and Control Yanshan University Qinhuangdao 066004 China Key Laboratory of Advanced Forging & Stamping Technology and Science Ministry of Education of China Yanshan University Qinhuangdao 066004 China Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China College of Engineering Peking University Beijing 100871 China School of Economics Renmin University of China Beijing 100872 China School of Economics Peking University Beijing 100871 China

With the accelerating coordinated development of the Beijing-Tianjin-Hebei region, regional eco- nomic integration is recognized as a national strategy. As water scarcity places Hebei Province in a dilemma, it is of critical importance for Hebei Province to balance water resources as well as make full use of its unique advantages in the transition to sustainable development. To our knowledge, related embodied water accounting analysis has been conducted for Beijing and Tianjin, while similar works with the focus on Hebei are not found. In this paper, using the most complete and recent statistics available for Hebei Province, the embodied water use in Hebei Province is analyzed in detail. Based on input-output analysis, it presents a complete set of systems accounting framework for water resources. In addition, a database of embodied water intensity is proposed which is applicable to both intermediate inputs and final demand. The result suggests that the total amount of embodied water in final demand is 10.62 billion m3, of which the water embodied in urban household consumption accounts for more than half. As a net embodied water importer, the water embodied in the commodity trade in Hebei Province is 17.20 billion m3. The outcome of this work implies that it is particularly urgent to adjust industrial structure and trade policies for water conservation, to upgrade technology and to improve water utilization. As a result, to relieve water shortages in Hebei Province, it is of crucial importance to regulate the balance of water use within the province, thus balancing water distribution in the various industrial sectors.

关键词： input-output analysis Hebei Province embo-died water embodied water intensity

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Effects of physical parameters of multiphase flow on fire water monitor based on Fluent

Effects of physical parameters of multiphase flow on fire wa...

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CSAA/IET International Conference on Aircraft Utility Systems (AUS 2018)

作者： Xiaoming Yuan Shiyi Zhao Chu Wang Lijie Zhang Hebei Key Laboratory of Heavy Machinery Fluid Power Transmission and Control with the Key Laboratory of Advanced Forging & Stamping Technology and Science Yanshan University Qinhuangdao China

ISBN: (纸本)9781510872745

To improve the jet performance of a fire water monitor, the monitor head with three different inner contour lines were designed. Based on FLUENT, the calculation domain was defined geometrically and then the cloud pictures of the flow velocity, pressure, turbulence kinetic energy and multiphase flow of the fluid field in the nozzle and jet were obtained, based on which the optimal structure of each model can be selected. The simulation result can provide the theoretical reference for the design of a monitor head.

关键词： Fire water monitor Jet performance Fluent

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