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Theoretical Model of Dynamic Bulk Modulus for Aerated Hydraulic Fluid

Chinese Journal of Mechanical Engineering 2022年第5期35卷 183-193页

作者： Xiaoming Yuan Weiqi Wang Xuan Zhu Lijie Zhang Hebei Key Laboratory of Heavy Machinery Fluid Power Transmission and Control Yanshan UniversityQinhuangdao 066004China Key Laboratory of Advanced Forging&Stamping Technology and Science Ministry of Education of ChinaYanshan UniversityQinhuangdao 066000China State Key Laboratory of Fluid Power and Mechatronic Systems Zhejiang UniversityHangzhou 310027China

Existing models of bulk modulus for aerated hydraulic fluids primarily focus on the effects of pressure and air fraction,whereas the effect of temperature on bulk modulus is *** on the lumped parameter method and the full cavitation model,combined with the improved Henry’s law and the air polytropic course equation,a theoretical model of dynamic bulk modulus for an aerated hydraulic fluid is *** effects of system pressure,air fraction,and temperature on bulk modulus are investigated using the controlled variable *** results show that the dynamic bulk modulus of the aerated hydraulic fluid is inconsistent during the compression *** the same pressure point,the dynamic bulk modulus during expansion is higher than that during *** the same initial air faction and pressure changing period,a higher temperature results in a lower dynamic bulk *** the pressure is lower,the dynamic bulk modulus of each temperature point is more similar to each *** comparing the theoretical results with the actual dynamic bulk modulus of the Shell Tellus S ISO32 standard air-containing oil,the goodness-of-fit between the theoretical model and experimental value at three temperatures is 0.9726,0.9732,and 0.9675,which validates the theoretical *** this study,a calculation model of dynamic bulk modulus that considers temperature factors is *** predicts the dynamic bulk modulus of aerated hydraulic fluids at different temperatures and provides a theoretical basis for improving the analytical model of bulk modulus.

关键词： Aerated hydraulic fluid Dynamic bulk modulus Theory model Air fraction Pressure

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Design and Analysis of a Novel Ring Truss Deployable Antenna Mechanism 16th

Design and Analysis of a Novel Ring Truss Deployable Antenna...

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16th International Conference on Intelligent Robotics and Applications, ICIRA 2023

作者： Han, Bo Yuan, Zhantu Zhou, Yuanzhi Liu, Feng Yao, Jiantao Zhao, Yongsheng Hebei Provincial Key Laboratory of Parallel Robot and Mechatronic System Yanshan University Qinhuangdao066004 China Key Laboratory of Advanced Forging and Stamping Technology and Science Yanshan University Ministry of Education of China Qinhuangdao066004 China

ISBN: (纸本)9789819965038

With the development of astronautics, satellite antenna as an important communication equipment has also gradually developed to large scale. In this paper, a novel ring truss deployable antenna mechanism is proposed. The mechanism has three layers of installation points with height differences between them, which can be used to ensure that all the installation points will be distributed on the profile of the cable network, and this characteristic ensures the mechanism can be utilized to the maximum. Then the degrees of freedom (DOF) and kinematics of the ring truss deployable mechanism are analyzed using screw theory, where the analysis shows that the DOF of the overall ring truss deployable mechanism is equal to one. Following that, the dynamics model about the mechanism unit is established using the second type of Lagrange equations. Based on this dynamic model, the effect of torsion spring stiffness on the deployment process is discussed and the conclusion is verified by simulation. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

关键词： Trusses

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An End-Traction Lower Extremity Rehabilitation Robot: Structural Design, Motion Analysis, and Experimental Validation 23rd

An End-Traction Lower Extremity Rehabilitation Robot: Struct...

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23rd IFToMM China International Conference on Mechanism and Machine science and Engineering, IFToMM CCMMS 2022

作者： Bian, Hui Yang, Fan Sun, Zhaoliang Li, Jiachen Ding, Jiebin Li, Shuai Hebei Provincial Key Laboratory of Parallel Robot and Mechatronic System Yanshan University Hebei Qinhuangdao066004 China Key Laboratory of Advanced Forging & Stamping Technology and Science Yanshan University Ministry of Education of China Hebei Qinhuangdao066004 China

ISBN: (纸本)9789811993978

An end-traction lower extremity rehabilitation robot named ETLER is designed to meet the rehabilitation needs of patients with lower extremity dysfunction at all stages of recovery, while taking into account the ease of operation for the patient. A single robot can meet the needs of a hemiplegic patient on either side for the designed end-change structure. The robots can also be used in pairs for patients with spinal cord injuries. Meanwhile, the adjustable ankle joint limit design provides customized training programs for the ankle joint. To carry out the trajectory planning of the rehabilitation robot, kinematic analysis and control strategy modeling of the robot and human–machine system are carried out. The functionality and universality of the rehabilitation robot are verified through comparative tests. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

关键词： Machine design

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Kinematics Analysis of a New Parallel Mechanism with Complete Separation of Constraints and Drives 16th

Kinematics Analysis of a New Parallel Mechanism with Complet...

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16th International Conference on Intelligent Robotics and Applications, ICIRA 2023

作者： Qiu, Can Wang, Yu Wu, Jiabin He, Xiaoyu Ma, Xuejian Xu, Yundou Zhao, Yongsheng Parallel Robot and Mechatronic System Laboratory of Hebei Province Yanshan University Qinhuangdao066004 China Key Laboratory of Advanced Forging and Stamping Technology and Science of Ministry of National Education Yanshan University Qinhuangdao066004 China

ISBN: (纸本)9789819964888

At present, there is a growing demand for parallel mechanisms with fewer inputs and more outputs. These mechanisms are highly sought after in industries such as aerospace, antenna, and entertainment facilities, among others. Therefore, this paper proposes a new parallel mechanism (PM) that utilizes separation of constraints and drives, resulting in centralized drive management. Thereby achieving a small amount of driving to drive multiple parallel moving platforms. For example, 3nRRS/PPPS parallel mechanism. In this study, we utilize the closed-loop vector method to obtain the inverse solution for the 3RRS/PPPS parallel mechanism. To perform a static analysis, we construct a complete Jacobian matrix for the mechanism. Under the premise of satisfying the workspace, the key dimensional parameters of the mechanism were optimized with the objective of improving the load-carrying capacity of the mechanism and minimizing the driving force. The method of complete separation of constraints and drives is easier to centrally manage drives, greatly improving energy utilization and work efficiency, and having a wide range of application scenarios in antenna, entertainment facilities, and other situations. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2023.

关键词： Inverse problems

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Microstructure evolution of 7050 aluminum forgings during surface cumulative plastic deformation

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Transactions of Nonferrous Metals Society of China 2025年第1期35卷 45-59页

作者： Jian-liang HU Ze-xiong ZHANG Cheng XING Xiu-jiang WU Shi-quan HUANG Hong BO Key Laboratory of Advanced Forging&Stamping Technology and Science Ministry of EducationYanshan UniversityQinhuangdao 066004China State Key Laboratory of Precision Manufacturing for Extreme Service Performance Central South UniversityChangsha 410083China College of Mechanical Engineering Yanshan UniversityQinhuangdao 066004China Hebei Engineering Technology Research Center of Metal Precision Plastic Processing Yanshan UniversityQinhuangdao 066004China State Key Laboratory of Metastable Materials Science and Technology Yanshan UniversityQinhuangdao 066004China

To elucidate the mechanisms of regulating the microstructure uniformity in 7050 aluminum forgings through surface cumulative plastic deformation(SCPD),the microstructure under different solution treatments was investigated using metallographic observation(OM),electron backscatter diffraction(EBSD),transmission electron microscopy(TEM),and X-ray diffraction(XRD).The findings demonstrate that the most uniform microstructure in the forgings is achieved with a solution treatment at 470℃for 30 *** SCPD process generates a significant number of needle-shaped precipitates,resulting in a higher dislocation density and stored *** treatments alleviate the pinning effect of second-phase particles and facilitate static recrystallization(SRX)in forgings,leading to a reduction in grain ***,mechanical testing results demonstrate 7%−13%increase in tensile strength and more uniform elongation of the forgings in different directions.

关键词： microstructure homogeneity surface cumulative plastic deformation(SCPD) static recrystallization(SRX) dislocation density

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Design and analysis of truss deployable antenna mechanism based on a novel symmetric hexagonal profile division method

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Chinese Journal of Aeronautics 2021年第8期34卷 87-100页

作者： Jinwei GUO Yongsheng ZHAO Yundou XU Yongjie LI Jiantao YAO Parallel Robot and Mechatronic System Laboratory of Hebei Province Yanshan UniversityQinhuangdao 066004China Key Laboratory of Advanced Forging&Stamping Technology and Science of Ministry of National Education Yanshan UniversityQinhuangdao 066004China

As the deployment,supporting,and stability mechanisms of satellite antennas,space-deployable mechanisms play a key role in the field of *** order to design truss deployable antenna supporting mechanisms with large folding rate,high accuracy,easy deployment and strong stability,aiming at the geometric division of the parabolic reflector,a novel method based on symmetric hexagonal division and its corresponding modular truss deployable antenna mechanism is proposed,and the original method based on asymmetric triangular division and its corresponding mechanisms are presented for comparative ***,the screw theory is employed to analyze the mobility of different ***,the improved three-dimensional mesh method is used to divide the reflector surface of a large parabolic antenna designed by the two different methods,and the profile accuracy and the type of links are taken as the evaluation indexes to quantitatively analyze the division ***,a three-dimensional model of the modular deployable mechanism based on the symmetric hexagonal design is developed,and the deployable mechanisms with different configurations based on the two design methods are compared and analyzed from the mechanical *** research results provide a good theoretical reference for the design of deployable truss antenna mechanisms and their application in the aerospace field.

关键词： Mobility Modular mechanism Profile division Screw theory Truss deployable antenna

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Optimal Design of Frame Structure of Center Axle Trailer Under Heavy Load Conditions 8th

Optimal Design of Frame Structure of Center Axle Trailer Und...

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8th International Conference on Advances in Construction Machinery and Vehicle Engineering, ICACMVE 2023

作者： Gao, Dongyu Ma, Jinyu Zheng, Huisai Zhang, Menzhe Zhao, Jingyi China Academy of Launch Vehicle Technology Beijing100076 China Beijing Institute of Precision Mechatronics and Controls Beijing100076 China Hebei Key Laboratory of Special Delivery Equipment Yunshan University Qinhuangdao066004 China Hebei Provincial Key Laboratory of Heavy Machinery Fluid Power Transmission and Control Yanshan University Qinhuangdao066004 China Key Laboratory of Advanced Forging and Stamping Technology and Science Yanshan University Qinhuangdao066004 China

ISBN: (纸本)9789819718757

In recent years, the mid axle train has gradually entered the transportation market because of its large loading capacity and flexible steering. The static simulation of full load bending, full load torsion and full load braking were carried out for the upper and lower platforms of the trailer frame, and the stress and deformation were obtained. Through the topology optimization design, the pseudo density cloud image with material removal as the optimization objective was obtained. The response surface optimization method was used to adjust the main optimization parameters of the frame platform, and the sensitivity value of its influence on the strength, stiffness and mass of the lightweight frame was analyzed. Finally, the actual value of the optimization parameters was determined. The results showed that the strength, stiffness, and stability of the lightweight frame met the requirements, and the total weight loss of the lightweight frame is 437.07 kg, and the weight loss ratio reached 14.51%. Finally, the static strength test of the lightweight frame was carried out, and the results showed that the lightweight frame met the use requirements. © The Author(s) 2024.

关键词： Stiffness

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Analysis of a Five-Degree-of-Freedom Hybrid Robot RPR/RP + RR + P 23rd

Analysis of a Five-Degree-of-Freedom Hybrid Robot RPR/RP + R...

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23rd IFToMM China International Conference on Mechanism and Machine science and Engineering, IFToMM CCMMS 2022

作者： Ma, Xuejian Xu, Yundou Wang, Yu Yang, Fan Zhao, Yongsheng Yao, Jiantao Zhou, Yulin Laboratory of Parallel Robot and Mechatronic System of Hebei Province Yanshan University Qinhuangdao066004 China Key Laboratory of Advanced Forging and Stamping Technology and Science Yanshan University Qinhuangdao066004 China School of Mechanical Engineering Yanshan University Qinhuangdao066004 China

ISBN: (纸本)9789811993978

This work proposes a hybrid machining robot RPR/RP + RR + P based on a planar parallel mechanism. Based on the screw theory, the characteristics of the degree of freedom of the hybrid robot are analyzed, and then the inverse and forward kinematics are solved by geometric methods. And size optimization is carried out by taking the workspace and driving forces as the objects. Then the working space of the hybrid robot is calculated by the Monte Carlo method. Finally, the three-dimensional model of the mechanism is established, and through ADAMS simulation, the accuracy of the inverse kinematics solution was verified. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

关键词： Inverse kinematics

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Research on the Process-based Generation Method of Multi-ships Collision Avoidance Test Scenarios Database for Maritime Autonomous Surface Ships 33rd

Research on the Process-based Generation Method of Multi-shi...

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33rd International Ocean and Polar Engineering Conference, ISOPE 2023

作者： Wang, Xinyu Wang, Yihang Bian, Hui Ma, Jilin Zhao, Xuan Qinhuangdao Branch China Classification Society Hebei China School of Mechanical Engineering Yanshan University Hebei China Parallel Robot and Mechatronic System Laboratory Hebei Province Hebei China Key Laboratory of Advanced Forging & Stamping Technology and Science Hebei China Science & Technology Innovation and Test Center Beijing China

ISBN: (纸本)9781880653807

This paper proposes a process-based method for generating virtual test scenarios for near-shore maritime autonomous surface ships (MASS) collision avoidance tests. The method includes a scenario complexity index to provide different difficulty levels of virtual test scenarios for different test requirements, reducing the test volume while ensuring coverage and reliability requirements. The scenario database generated by this method reflects the frequency of real-world scenarios and meets the requirements of virtual test realism. This method can improve the efficiency and reliability of MASS testing, with potential future improvements in the complexity evaluation matrix and statistical analysis of vessel maneuvering ability. © 2023 by the International Society of Offshore and Polar Engineers (ISOPE).

关键词： Ships

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Kinematic,Workspace and Force Analysis of A Five-DOF Hybrid Manipulator R(2RPR)R/SP+RR

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Chinese Journal of Mechanical Engineering 2022年第5期35卷 232-243页

作者： Yundou Xu Fan Yang Youen Mei Dongsheng Zhang Yulin Zhou Yongsheng Zhao Laboratory of Parallel Robot and Mechatronic System of Hebei Province Yanshan UniversityQinhuangdao 066004China Key Laboratory of Advanced Forging&Stamping Technology and Science of Ministry of National Education Yanshan UniversityQinhuangdao 006004China School of Mechanical Engineering Yanshan UniversityQinhuangdao 066004China Tencent Robotics X Tencent HoldingsShenzhen 518057China

In the present study,the over-constrained hybrid manipulator R(2RPR)R/SP+RR is considered as the research *** this paper,kinematics of the hybrid manipulator,including the forward and inverse position,are ***,the workspace is checked based on the inverse position solution to evaluate whether the workspace of the hybrid manipulator meets the requirements,and the actual workspace of the hybrid robot is *** that,the force analysis of the over-constrained parallel mechanism is carried out,and an ADAMS-ANSYS rigid-flexible hybrid body model is established to verify the *** on the obtained results from the force analysis,the manipulator structure is ***,the structure optimization is carried out to improve the robot ***,calibration and workspace verification experiments are performed on the prototype,cutting experiment of an S-shaped aluminum alloy workpiece is completed,and the experiment verifies the machining ability of the *** work conducts kinematics,workspace,force analyses,structural optimization design and experiments on the over-constrained hybrid manipulator R(2RPR)R/SP+RR,providing design basis and technical support for the development of the novel hybrid manipulator in practical engineering.

关键词： Hybrid manipulator Over-constrained Kinematic analysis Stiffness analysis

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