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Research on double differential pressure dynamic flowmeter

High technology Letters 2019年第4期25卷 378-385页

作者： Liu Tao Zuo Zhibing Yin Zhigang Hebei Province Laboratory of Heavy Machinery Fluid Power Transmission and Control Yanshan UniversityQinhuangdao 066004P.R.China Key Laboratory of Education Ministry for Advanced Forging Press Technology and Science Yanshan UniversityQinhuangdao 066004P.R.China

When testing an electrohydraulic proportional valve,it is necessary to test the high frequency dynamic flow with *** of the limitation of the piston stroke,a no-load hydraulic cylinder is only suitable for a reciprocating symmetrical dynamic flow *** the traditional differential pressure flowmeter is affected by viscosity and inertia of the fluid,it is only suitable for measuring steady ***,a new type of double pressure differential dynamic flowmeter is designed to improve the traditional differential pressure *** influence of fluid viscosity and inertia in the flow process are negated by subtracting the differential pressure in section expansion from the differential pressure in section *** double differential pressure flowmeter is modeled and a flow meter prototype is ***,the flow coefficients are identified and corrected by a practical ***,the dynamic performance and steady-state precision of the flowmeter are verified by comparing with the test results of the no-load hydraulic *** double differential pressure dynamic flowmeter is proven to measure dynamic flow accurately,especially at higher dynamic frequencies.

关键词： dynamic flowmeter double differential pressure contrast experiment coefficient correction

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Deformation behavior and micro-twins mechanisms of a cast & wrought FGH4096 superalloy during hot compression

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Journal of Alloys and Compounds 2025年 1033卷

作者： Kai Chang Yi Tan Chenxi Ma Rusheng Bai Pengting Li Chi Zhang Yinong Wang Key Laboratory of Materials Modification by Laser Ion and Electron Beams (Dalian University of Technology) Ministry of Education School of Materials Science and Engineering Dalian 116024 China Key Laboratory for Energy Beam Metallurgy and Advanced Materials Preparation of Liaoning Province Dalian 116024 China

Deformation micro-twinning, as a key deformation mechanism during plastic deformation, significantly enhances the high-temperature deformation plasticity of alloys. In this study, FGH4096 alloy with a strong texture was prepared using electron beam directional solidification (EBDS) technology. By altering the deformation direction of the columnar grains to introduce micro-twin structures, the deformation capability of the FGH4096 alloy was coordinated, significantly enhancing its hot deformation plasticity, and the microstructure evolution and micro-twin formation during hot compression of the cast and forged FGH4096 alloy were investigated. Clear micro-twin structures were observed only in the 0° deformation samples, which is attributed to the suppression of cross-slip and the evolution of the texture type, which facilitates the formation of micro-twin structures. The study also provides a detailed discussion of the influence of deformation behavior, load direction, texture type, and Schmid factor on the micro-twin formation mechanism. These findings enhance the understanding of the complex interactions between crystal orientation, texture evolution, the Schmid factor, and the micro-twinning deformation mechanism. The results offer valuable insights into improving the high-temperature formability of cast & wrought FGH4096 superalloy, providing a pathway for substituting powder metallurgy with casting and forging techniques in producing turbine disk materials.

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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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Study on principles and characteristics of new type digital hydraulic transformation 8

Study on principles and characteristics of new type digital ...

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8th IEEE International Conference on Fluid Power and Mechatronics, FPM 2019

作者： Tao, Liu Yang, Zhao Renfu, Sun Weijian, Li Xinyu, Zhang Hebei Province Laboratory of Heavy Machinery Fluid Power Transmission and Control Qinhuangdao China Key Laboratory of Ministry of Education for Advanced Forging Press Forming Technology and Science Qinhuangdao China

ISBN: (纸本)9781728103112

The hydraulic transformer is usually composed of a pair of pump-motor units. When inlet pressure is stable, the outlet pressure can be controlled by changing the displacement ratio between the pump unit and motor unit. Theoretically, there is no throttling and overflow loss, so it attracts much attention in fluid transmission field. However, most of the existing hydraulic transformers are controlled by the displacement-varying mechanism, with slow response and small range of transformer ratio. Therefore, a new type of digital hydraulic transformer was proposed. The main body is a group of gear pump motor units, which are installed in coaxial direction, and the displacement ratios between these units is arranged according to 2n in every inlet and outlet of these gear pump motor units, there are digital switch valves to realize the digital control of pressure change. Using simulation software AMESIM, the conversion process of digital hydraulic transformer is simulated and analyzed, the characteristics of pressure, flow and transformation ratio are verified during the working process. The characteristics of transformer under constant voltage network were tested by building an experimental platform. By changing the pressure and load of constant voltage network, the working characteristics of digital hydraulic transformer under different working conditions are studied. The feasibility of the variable pressure principle is verified, and the energy saving characteristics of the digital hydraulic transformer are proved. © 2019 IEEE.

关键词： Energy conservation

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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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Instability analysis of free deformation zone of cylindrical parts based on hot-granule medium-pressure forming technology

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Transactions of Nonferrous Metals Society of China 2016年第8期26卷 2188-2196页

作者： Miao-yan CAO Chang-cai ZHAO Guo-jiang DONG Sheng-fu YANG College of Mechanical Engineering Yanshan University Qinhuangdao 066004 China Key Laboratory of Advanced Forging & Stamping Technology and Science Ministry of Education Yanshan University Qinhuangdao 066004 China College of Vehicles and Energy Yanshan University Qinhuangdao 066004 China

The cylindrical part of sheet metal based on hot-granule medium-pressure forming (HGMF) technology was *** stress functions of the free deformation zone and the fracture instability theory were combined to establish the analytical expression of the critical pressure of punch. The results show that the active friction between the granule medium and the sheet metal, as well as the non-uniform internal pressure presented by the solid granule medium, can obviously improve the forming performance of the sheet metal. The critical pressure of punch increases with the increment of the friction coefficient between the granule medium and sheet metal, as well as the plastic strain ratio, whereas it decreases with the increase of the material-hardening exponent. Furthermore, the impact on the critical pressure from high to low order is the plastic strain ratio, the friction coefficient,and material-hardening exponent. The deep-drawing experiment with HGMF technology on AZ31B magnesium alloy sheet verified the instability *** words: hot-granule

关键词： hot-granule medium-pressure forming deep-drawing instability cylindrical part

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Influence of liquid film thickness on bearing characteristics of magnetic-liquid suspension guide-way

Influence of liquid film thickness on bearing characteristic...

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19th International Conference of Fluid Power and Mechatronic Control Engineering 2018

作者： Zhao, Jianhua Zhang, Bin Chen, Tao Wang, Qiang Gao, Dianrong Key Laboratory of Advanced Forging and Stamping Technology and Science Hebei Provincial Key Laboratory of Heavy Machinery Fluid Power Transmission and Control Yanshan University Qinhuangdao066004 China

The magnetic-liquid suspension guide-way (MLSG) adopts the double support form of permanent magnetic suspension and hydrostatic pressure. It can greatly enhance the bearing capacity and rigidity of the guide-way system. The liquid film thickness is the main influencing factor on both the bearing capacity of the hydrostatic system and the permanent magnetic force. This paper analysed the effect of liquid film thickness on the static, dynamic and vibration index of MLSG. Firstly, this paper introduced the structural characteristics and supporting mechanism of MLSG. Secondly, based on flow equation, the static pressure equation, the permanent magnetic force equation and the force balance equation, the transfer function of single DOF supporting system of MLSG in constant flow supply mode is presented, and analysed the influence of the thickness of liquid film on single DOF supporting performance of MLSG. The results show that with the increase of the thickness of the liquid film, the bearing capacity of guide-way, the static stiffness, the dynamic stiffness and the natural frequency decrease, and the adjust time, the total power loss, the amplitude amplification coefficient increases, the phase margin is almost unchanged. The study can provide a theoretical basis for the design of MLGS in engineering practice. © 2019 Institution of Engineering and technology. All rights reserved.

关键词： Bearing capacity

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Reliability prediction method of hydraulic system by fuzzy theory

Reliability prediction method of hydraulic system by fuzzy t...

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6th IFAC Symposium on Mechatronic Systems, MECH 2013

作者： Chen, Dongning Yao, Chengyu Feng, Zhongkui Hebei Provincial Key Laboratory of Heavy Machinery Fluid Power Transmission and Control Yanshan University Qinhuangdao China Key Laboratory of Advanced Forging and Stamping Technology and Science Yanshan University Ministry of Education of China Qinhuangdao China Key Laboratory of Industrial Computer Control Engineering of Hebei Province Yanshan University Qinhuangdao China

ISBN: (纸本)9783902823311

The hydraulic system's reliability is a key factor to ensure the reliable operation of equipment and it is very important to evaluate reliability of hydraulic system. The paper describes a reliability prediction method that may be used to evaluate the reliability of hydraulic systems for industrial applications. The proposed method takes advantage of fuzzy set theory. The aim of this method is to minimize the deficiencies of the traditional reliability prediction methods treating a failure rate as fixed value due to insufficiency practice data. Triangular fuzzy number and Gaussian fuzzy number are used in the application of this prediction method, where environmental factor, derating factor, and other factors are considered. Finally, an example of type crane's hydraulic system is given to verify the feasibility and practicability of the method. © 2013 IFAC.

关键词： Fuzzy set theory

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Reliability optimization of multi-state hydraulic system based on T-S fault tree and extended PSO algorithm

Reliability optimization of multi-state hydraulic system bas...

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6th IFAC Symposium on Mechatronic Systems, MECH 2013

作者： Yao, Chengyu Wang, Bin Chen, Dongning Key Laboratory of Industrial Computer Control Engineering of Hebei Province Yanshan University Qinhuangdao China Hebei Provincial Key Laboratory of Heavy Machinery Fluid Power Transmission and Control Yanshan University Qinhuangdao China Key Laboratory of Advanced Forging and Stamping Technology and Science Yanshan University Ministry of Education of China Qinhuangdao China

ISBN: (纸本)9783902823311

In order to overcome the difficulty of constructing the multi-state system's reliability optimization model, and the shortage of premature convergence of PSO (Particle Swarm Optimization) algorithm, a new reliability optimization method based on T-S fault tree and EPSO (Extended PSO) algorithm is proposed. According to the T-S fault tree and T-S rules of the events, the multi-state system reliability optimization model is constructed, at the same time, given constraint conditions on the system cost, weight and volume, and combined with the death penalty to construct the fitness function. Furthermore, EPSO algorithm based on the attraction and repulsion forces in the artificial physics is applied to the reliability optimization of multi-state hydraulic system. Comparing with PSO algorithm, the results of EPSO algorithm are in a better performance in obtaining global optimal solution. © 2013 IFAC.

关键词： Trees (mathematics)

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Force measurement method and analysis of guide wire in minimally invasive cardiovascular interventional surgery

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Journal of Chemical and Pharmaceutical Research 2014年第1期6卷 266-270页

作者： Yang, Xue Wang, Hongbo Wang, Qiang Wu, Jianshuang Parallel Robot and Mechatronic System Laboratory of Hebei Province China Key Laboratory of Advanced Forging and Stamping Technology and Science of Ministry of Education Yanshan University China

This paper presents a method of detecting the resistant force that acting on the guide wire when it moving into the body blood vessel for minimally invasive cardiovascular interventional surgery operated by a robot system. To learn more about the influenced factors for measured force, some simulations of body blood flow environment have been given. And then some analyses have been worked on blood flow to study whether the parameters of blood flow influence the resistant force measurement results. All of these studies will make us know more about the reliability of this force detecting method and lay the foundation for realizing force feedback in minimally invasive surgery robot system to further improve the system reliability.

关键词： Blood vessels

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