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Microstructure evolution of 7050 aluminum forgings during surface cumulative plastic deformation

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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Hot tensile deformation behavior and constitutive model of ZK61M high-strength magnesium alloy sheet

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Rare Metals 2021年第5期40卷 1182-1190页

作者： Liu Yang Yong-Chuan Duan Ying-Ping Guan Zhen-Hua Wang Key Laboratory of Advanced Forging&Stamping Technolnology and Science Ministry of Education of ChinaYanshan UniversityQinhuangdao 066004China School of Mechanical Engineering Yanshan UniversityQinhuangdao 066004China

Hot deformation behavior of the annealed ZK61 M magnesium alloy sheet was explored using tensile tests with strain rates varying from 0.001 to 0.030 s^(-1) in temperatures range of 423-513 *** obtained results indicate that the flow stress increased with deformation temperature decreasing and strain rate *** recrystallization(DRX)occurs when the temperature is higher than 423 K,and the recrystallization volume fraction increases with temperature *** a given temperature,the measured DRX volume fraction at a higher strain rate is smaller than that at a lower strain *** are observed throughout the tested temperature ***,they grow larger as temperature *** average absolute relative error(AARE)of 2.65%proves that the peak stress predicted by the constitutive model is in good agreement with the experimental *** correlation coefficient(R’)obtained for the predicted stress and the experimental value considering the strain on the material constant are between 0.9831 and *** addition,AARE and root mean square error(RMSE)are less than 6.5%and 8.5 MPa,*** indicates that the deviation of the predicted value from the experimental value is small and the predictions of the proposed model are reliable.

关键词： ZK61M magnesium alloy sheet Hot tensile deformation Microstructure Constitutive model

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Kinetic analysis of austenite transformation for B1500HS high-strength steel during continuous heating

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International Journal of Minerals,Metallurgy and Materials 2020年第11期27卷 1508-1516页

作者： Mu-yu Li Dan Yao Liu Yang Hao-ran Wang Ying-ping Guan Key Laboratory of Advanced Forging&Stamping Technology and Science(Ministry of Education of China) Yanshan UniversityQinhuangdao 066004China School of Mechanical Engineering Yanshan UniversityQinhuangdao 066004China

The dilatometric curves of B1500HS high-strength steel at different heating rates were measured by a Gleeble-3800 thermal simulator and analyzed to investigate the effect of heating rate on *** show that the value of starting temperature and ending temperature of austenite transformation increase with the rise of heating rates,whereas the temperature interval of austenite formation *** kinetic equation of austenite transformation was solved using the Johnson–Mehl–Avrami model,and the related parameters of the equation were analyzed by the Kissinger *** those calculations,the activation energy of austenite transformation is 1.01×10^6 J/mol,and the values of kinetic parameters n and ln k0 are 0.63 and 103.03,*** relationship between the volume fraction of austenite and the heating time at different heating rates could be predicted using the kinetic *** predicted and experimental results were compared to verify the accuracy of the kinetic *** microstructure etched by different corrosive solutions was analyzed,and the reliability of kinetic equation was further verified from the microscopic perspective.

关键词： B1500HS high-strength steel dilatometric curve austenite transformation kinetic equation Johnson-Mehl-Avuami model

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Analysis of Vibration Characteristics of Electro-hydraulic Driven 3-UPS/S Parallel Stabilization Platform

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Chinese Journal of Mechanical Engineering 2024年第6期37卷 212-224页

作者： Xiaoming Yuan Weiqi Wang Haodong Pang 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 EducationYanshan UniversityQinhuangdao 066004China

With the development of fluid-power transmission and control technology,electro-hydraulic-driven technology can significantly improve the load-carrying capacity,stiffness,and control accuracy of stabilization ***,compared with mechanically driven platforms,the stiffness and damping of the fluid,as well as the coupling effect between the fluid and the structure need to be considered for electro-hydraulic-driven parallel stabilization platforms,making the modal and dynamic response characteristics of the mechanism more *** the aim of solving the aforementioned issues,we research the electro-hydraulic driven 3-UPS/S parallel stabilization platform considering the hinge ***,the characteristic vibration equation of the mechanism is established using the virtual work ***,the variation characteristics of the natural frequency and the vibration response according to the position of the mechanism are analyzed based on the dynamic ***,the correctness of the model is verified by a modal test and Runge-Kutta *** study provides a theoretical basis for the dynamic design of electrohydraulic-driven parallel mechanisms.

关键词： Electro-hydraulic driven 3-UPS/S parallel stabilization platform Kinetic equation Vibration mode Vibration response Modal test

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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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Design and dynamic analysis of a scissors hoop-rib truss deployable antenna mechanism

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Defence Technology（防务技术） 2023年第6期24卷 399-413页

作者： Bo Han Xiangkun Li Jian Sun Yundou Xu Jiantao Yao Yongsheng Zhao Parallel Robot and Mechatronic System Laboratory of Hebei Province Yanshan UniversityQinhuangdao066004China Key Laboratory of Advanced Forging&Stamping Technology and Science Ministry of Education of ChinaYanshan UniversityQinhuangdao066004China

As the support mechanism of space-borne antennas,space deployable antenna mechanism belongs to complex multi-closed-loop coupling mechanism,configuration design and dynamic analysis are more difficult than general parallel *** this paper,an unequal-length scissors mechanism(ULSM)is proposed by changing the position of the internal rotational joint through a basic scissors mechanism.A scissors hoop-rib truss deployable antenna mechanism(SHRTDAM)is constructed by replacing the parabolic rib with the *** analysis of SHRTDAM is conducted,and the degree of freedom(DOF)of the whole antenna mechanism is analyzed based on screw theory,the result showed that it has only one *** and acceleration characteristics of SHRTDAM are obtained by the screw derivative and rotation *** on Lagrange equation,dynamic model of this mechanism is established,the torque required to drive the mechanism is simulated and verified by Adams and MATLAB *** addition,a ground experiment prototype of 1.5-m diameter was fabricated and a deployment test is conducted,which demonstrated the mobility and deployment performance of the whole *** mechanism proposed in this paper can provide a good reference for the design and analysis of large aperture space deployable antennas.

关键词： Scissors mechanism Deployable antenna Screw theory Kinematic analysis Dynamic analysis

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Compound Impedance Control of a Hydraulic Driven Parallel 3UPS/S Manipulator

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Chinese Journal of Mechanical Engineering 2020年第4期33卷 63-76页

作者： Lihang Wang Shaofei Cui Chong Ma 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 066004China

The hydraulic parallel manipulator combines the high-power density of the hydraulic system and high rigidity of the parallel mechanism with excellent load-carrying ***,the high-precision trajectory tracking control of the hydraulic parallel manipulator is challenged by the coupling dynamics of the parallel mechanism and the high nonlinearities of the hydraulic *** this study,the trajectory control of a 3-DOF symmetric spherical parallel 3UPS/S manipulator is *** on the highly coupling and nonlinear system dynamics,a compound impedance control method for a hydraulic driven parallel manipulator is proposed,which combines impedance control with the spatial motion characteristics of a parallel *** control strategy is divided into the inner and outer *** inner loop controls the impedance of the actuator in the joint space,and the outer loop controls the impedance of the entire platform in the task space to compensate the coupling of the actuators and improve the tracking accuracy of the moving *** impedance control does not require force or pressure sensors and is less dependent on modeling *** experimental results show that the compound impedance control effectively improves the tracking accuracy of the moving *** research proposes a compound impedance control strategy for a 3-DOF hydraulic parallel manipulator,which has high tracking precision with a simple and cheap system configuration.

关键词： Parallel manipulator Impedance control Hydraulic servo system Trajectory tracking

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Development of a Wearable Upper Limb Rehabilitation Robot Based on Reinforced Soft Pneumatic Actuators

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Chinese Journal of Mechanical Engineering 2022年第4期35卷 182-190页

作者： Xinbo Chen Shuai Zhang Kaibin Cao Chunjie Wei Wumian Zhao 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

Dyskinesia of the upper limbs caused by stroke,sports injury,or trafc accidents limits the ability to perform the activities of daily *** the necessary medical treatment,correct and scientifc rehabilitation training for the injured joint is an important auxiliary means during the treatment of the efected upper *** upperlimb rehabilitation robots have some disadvantages,such as a complex structure,poor compliance,high cost,and poor *** this study,a novel soft wearable upper limb rehabilitation robot(SWULRR)with reinforced soft pneumatic actuators(RSPAs)that can withstand high pressure and featuring excellent loading characteristics was *** by RSPAs,this portable SWULRR can perform rehabilitation training of the wrist and elbow *** this study,the kinematics of an SWULRR were analyzed,and the force and motion characteristics of RSPA were studied *** results provide a reference for the development and application of wearable upper limb rehabilitation *** experimental study on the rotation angle of the wrist and the pressure of the RSPA was conducted to test the efect of the rehabilitation training and verify the rationality of the theoretical *** process of wrist rehabilitation training was tested and evaluated,indicating that SWULRR with RSPAs will enhance the fexibility,comfort,and safety of rehabilitation *** work is expected to promote the development of wearable upper-limb rehabilitation robots based on modular reinforced soft pneumatic actuators.

关键词： Upper limb rehabilitation Reinforced soft pneumatic actuator Wearable rehabilitation robot Motion analysis

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Type synthesis of deployable mechanisms for ring truss antenna based on constraint-synthesis method

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Chinese Journal of Aeronautics 2020年第9期33卷 2445-2460页

作者： Bo HAN Yundou XU Jiantao YAO Dong ZHENG Luyao GUO Yongsheng ZHAO 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

Space deployable antenna is the key equipment in realizing the communication and data transmission between the spacecraft and the *** order to enrich the configurations of deployable antennas,the type synthesis of deployable mechanisms for ring truss antenna is conducted in this ***,the principle of the constraint-synthesis method based on screw theory is briefly described,the structure of the ring truss deployable antenna and its folding principle are analyzed,and the ring truss mechanism is divided into upper edges,lower edges and ***,based on the constraint-synthesis method,the type synthesis of the basic unit edges is carried out,a series of basic unit mechanisms are obtained from combining the basic unit edge mechanisms,and five mechanism units with fewer joints and simple structures are ***,simulation models of the five ring truss deployable mechanisms are built in Solidworks and Matlab software,and the deploying process is verified by the movement ***,mechanism characteristics of the five mechanisms are analyzed and discussed,and a prototype is manufactured,verifying the analysis in this *** research provides a new way for the type synthesis of spatial deployable mechanisms,and the ring truss deployable mechanisms obtained in this study can be well applied in the field of aerospace.

关键词： Constraint-synthesis method Deployable mechanism Ring truss antenna Screw theory Type synthesis

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Force Analysis of the Overconstrained Mechanisms Based on Equivalent Stiffness Considering Limb Axial Deformation

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Chinese Journal of Mechanical Engineering 2023年第1期36卷 292-304页

作者： Jinwei Guo Yongsheng Zhao Bo Chen Guoxing Zhang Yundou Xu Jiantao Yao Parallel Robot and Mechatronic System Laboratory of Hebei Province Yanshan UniversityQinhuangdao066004China Key Laboratory of Advanced Forging&Stamping Technology and Science of Ministry of National Education Yanshan UniversityQinhuangdao066004China

Overconstrained mechanism has the advantages of large bearing capacity and high motion reliability,but its force analysis is complex and difficult because the mechanism system contains *** the limb axial deformation,taking typical 2SS+P and 7-SS passive overconstrained mechanisms,2SPS+P and 7-SPS active overconstrained mechanisms,and 2SPS+P and 7-SPS passive-input overconstrained mechanisms as examples,a new force analysis method based on the idea of equivalent stiffness is *** equivalent stiffness matrix of passive overconstrained mechanism is derived by combining the force balance and deformation compatibility equations with consideration of axial elastic limb *** relationship between the constraint wrench magnitudes and the external force,limb stiffness is *** equivalent stiffness matrix of active overconstrained mechanism is derived by combining the force balance and displacement compatibility ***,the relationship between the magnitudes of the actuated wrenches and the external force,limb stiffness is *** with the equivalent stiffness of the passive overconstrained mechanism,an analytical relationship between the actuated forces of passive-input overconstrained mechanism and the output displacement,limb stiffness is ***,adaptability of the equivalent stiffness to overconstrained mechanisms is discussed,and the effect of the limb stiffness on overconstrained mechanisms force distribution is *** research results provide a theoretical reference for the design,research and practical application of overconstrained mechanism.

关键词： Active overconstrained Passive overconstrained Passive-input overconstrained Equivalent stiffness Force distribution

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