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Determination of Elastoplastic Mechanical Properties of the Weld and Heat Affected Zone Metals in Tailor-Welded Blanks by Nanoindentation Test

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Chinese Journal of Mechanical Engineering 2015年第5期28卷 911-918页

作者： MA Xiangdong GUAN Yingping YANG Liu Key Laboratory of Advanced Forming & Stamping Technology and Science of Ministry of Education Yanshan University

The elastoplastic mechanical properties of the weld and heat affected zone metals have comparatively major impact on the forming process of tailor-welded blanks. A few scholars investigated the elastoplastic mechanical properties of the weld and heat affected zone, but they only simply assumed that it was a uniform distribution elastoplastic material different from the base materials. Four types of tailor-welded blanks which consist of ST12 and 304 stainless steel plates are selected as the research objects, the elastoplastic mechanical properties of the tailor-welded blanks weld and heat affected zone metals are obtained based on the nanoindentation tests, and the Erichsen cupping tests are conducted by combining numerical simulation with physical experiment. The nanoindentation tests results demonstrate that the elastoplastic mechanical properties of the weld and heat affected zone metals are not only different from the base materials, but also varying between the weld metals and the heat affected zone metals. Comparing the Erichsen cupping test resulted from numerical with that from experimental method, it is found that the numerical value of Erichsen cupping test which consider the elastoplastic mechanical properties of the weld and heat affected zone metals have a good agreement with the experimental result, and the relative error is only 4.8%. The proposed research provides good solutions for the inhomogeneous elastoplastic mechanical properties of the tailor-welded blanks weld and heat affected zone metals, and improves the control performance of tailor-welded blanks forming accuracy.

关键词： tailor-welded blanks elastoplastic mechanical properties nanoindentation test Erichsen cupping test

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Type Synthesis of Two-Degrees-of-Freedom Rotational Parallel Mechanism with Two Continuous Rotational Axes

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Chinese Journal of Mechanical Engineering 2016年第4期29卷 694-702页

作者： XU Yundou ZHANG Dongsheng WANG Min YAO Jiantao ZHAO Yongsheng Parallel Robot and Mechatronic System Laboratory of Hebei Province Yanshan University Key Laboratory of Advanced Forging and Stamping Technology and Science of Ministry of National Education Yanshan University Library Yanshan University

The two-rotational-degrees-of-freedom（2R） parallel mechanism（PM） with two continuous rotational axes（CRAs） has a simple kinematic *** is therefore easy to implement trajectory planning,parameter calibration,and motion control,which allows for a variety of application ***,no systematic analysis on structural constraints of the 2R-PM with two CRAs has been performed,and there are only a few types of 2R-PM with two ***,a theory regarding the type synthesis of the 2R-PM with two CRAs is systematically ***,combining the theories of reciprocal screw and space geometry,the spatial arrangement relationships of the constraint forces applied to the moving platform by the branches are explored,which give the 2R-PM two *** different distributions of the constraint forces in each branch are also *** the basis of the obtained structural constraints of branches,and considering the geometric relationships of constraint forces in each branch,the appropriate kinematic chains are *** the reasonable configuration of branch kinematic chains corresponding to every structural constraint,a series of new 2R-PMs with two CRAs are finally obtained.

关键词： type synthesis continuous rotational axes two rotational degrees of freedom parallel mechanism constraint force

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Application of Parallel Mechanism in Varistructured Quadruped/Biped Human-carrying Walking Chair Robot

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International Journal of Automation and computing 2013年第5期10卷 447-454页

作者： Ling-Feng Sang Hong-Bo Wang Dian-Fan Zhang Zhen-Hua Tian Fu-Hai Deng De-Lei Fang Parallel Robot and Mechatronic System Laboratory of Hebei Province Yanshan University Key Laboratory of Advanced Forging & Stamping Technology and Science of Ministry of Education Yanshan University Science and Technology Research Institute Yanshan University

For the existing problems of walking chair robot such as simple function,lower bearing capacity and not walking in complex environment,a novel varistructured quadruped / biped human-carrying walking chair robot is *** proposed robot could be used as biped and quadruped walking chair *** the conversion of the walking chair robot from the quadruped to the biped or vice versa,6-UPS and 2-UPS＋UP（U,P and S are universal joint,the prismatic pair,and sphere joint,respectively） parallel mechanisms are selected as the leg mechanism of the biped walking robot and quadruped walking robot,*** the screw theory and theory of mechanism,the degrees of freedom of the leg mechanism and the body mechanism in diferent motion states are computed so as to meet the requirements of mechanism *** motion characteristics of the 2-UPS＋UP parallel mechanism which is the key part of the walking chair robot are ***,the workspace of the moving platform is drawn and the efect of the structural parameters on the workspace volume is ***,it is found that the volume of the workspace of the moving platform is bigger when the side length ratio and the vertex angle ratio of the fxed platform and the moving platform which are isosceles triangles are close to *** study provides a theoretical foundation for the prototype development.

关键词： Human-carrying walking chair robot parallel leg mechanism degree of freedom varistructure workspace kinematics

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Finite element simulation and experimental test of the wear behavior for self-lubricating spherical plain bearings

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Friction 2018年第3期6卷 297-306页

作者： Yahong XUE Jigang CHEN Sumin GUO Qingliang MENG Junting LUO School of Mechanical Engineering Yanshan University Aviation Key Laboratory of Science and Technology on Generic Technology of Self-Lubricating Spherical Plain Bearing Yanshan University Education Ministry Key Laboratory of Advanced Forging and Stamping Technology and Science Yanshan University

In this study, based on the classical Archard adhesion wear theory, a three-dimensional finite element model was established, with the aim of simulating the failure process of self-lubricating spherical plain bearings in the swinging wear condition. The results show that the self-lubricating spherical plain bearings go through two different stages during the wear process, namely, initial wear stage and stable wear stage. Because the large contact points wear out during the initial wear stage, the maximum contact pressure decreases as the test period increases. The relatively larger wear depth region shows elliptical distribution, and the maximum distribution appears in the central contact area. The wear depth reaches 0.974 mm after swinging 25,000 times. PTFE fibers, which possess a good friction performance but poor abrasion resistance, abundantly exist on the friction surfaces of the fabric liner. Consequently, the friction torque during the initial wear stage is slightly smaller than the friction torque during the stable wear stage; however, the wear rate during the initial wear stage is high. The reliability and effectiveness of the finite element model are verified by experiment. The developed finite element model can be used for the analysis of the wear mechanisms of bearings and the prediction of the service life of bearings.

关键词： spherical plain bearing wear mechanisms wear depth contact pressure simulation

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Operation and Force Analysis of the Guide Wire in a Minimally Invasive Vascular Interventional Surgery Robot System

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Chinese Journal of Mechanical Engineering 2015年第2期28卷 249-257页

作者： YANG Xue WANG Hongbo SUN Li YU Hongnian Parallel Robot and Mechatronic System Laboratory of Hebei Province Yanshan University School of Mechanical Engineering University of Jinan Key Laboratory of Advanced Forging & Stamping Technology and Science of Ministry of Education Yanshan University Faculty of Science and Technology Bournemouth University

To develop a robot system for minimally invasive surgery is significant,however the existing minimally invasive surgery robots are not applicable in practical operations,due to their limited functioning and weaker perception.A novel wire feeder is proposed for minimally invasive vascular interventional *** is used for assisting surgeons in delivering a guide wire,balloon and stenting into a specific lesion *** contrasting those existing wire feeders,the motion methods for delivering and rotating the guide wire in blood vessel are described,and their mechanical realization is presented.A new resistant force detecting method is given in *** change of the resistance force can help the operator feel the block or embolism existing in front of the guide *** driving torque for rotating the guide wire is developed at different *** the CT reconstruction image and extracted vessel paths,the path equation of the blood vessel is *** the shapes of the guide wire outside the blood vessel,the whole bending equation of the guide wire is *** is a risk criterion in the delivering *** process can make operations safer and man-machine interaction more reliable.A novel surgery robot for feeding guide wire is designed,and a risk criterion for the system is given.

关键词： minimally invasive wire feeder force analysis moment of inertia risk criterion

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An Iterative Compensation Algorithm for Springback Control in Plane Deformation and Its Application

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Chinese Journal of Mechanical Engineering 2019年第2期32卷 212-223页

作者： Rui Ma Chunge Wang Ruixue Zhai Jun Zhao Key Laboratory of Advanced Forging & Stamping Technology and ScienceMinistry of Education of China Yanshan University College of Mechanical Engineering Yanshan University College of Mechanical and Energy Engineering Ningbo Institute of Technology Zhejiang University Key Laboratory of Roll Forming Technology Research

In order to solve the springback problem in sheet metal forming, the trial and error method is a widely used method in the factory, which is time-consuming and costly for its non-direction and non-quantitative. Finite element simulation is an e ective method to predict the springback of complex shape parts, but its precision is sensitive to the simulation model, particularly material model and boundary conditions. In this paper, the simple iterative method is introduced to establish the iterative compensation algorithm, and the convergence criterion of iterative parameters is put forward. In addition, the new algorithm is applied to the V-free bending and stretch-bending processes, and the convergence of curvature and bending angle is proved theoretically and verified experimentally. At the same time,the iterative compensation experiments for plane bending show that, the new method can predict the next compensaantido tnh ev atlaureg ebta cseurdv oatnu trhe ew sitphri tnhgeb earcrko ro fo fe laecshs ttehsat,n s0 o. 5 th%a ta rteh eo btatraigneet db aefntedri n2 g-3 a nitgelrea tiwoitnhs.t Thhei se rrreosre aorf clhe sps rtohpaons e±s 0 a.1%new iterative compensation algorithm to predict springback in sheet metal forming process, where each compensation value depends only on the iteration parameter di erence before and after springback for the same forming process of same material.

关键词： Springback control Iterative compensation algorithm Convergence criterion V-free bending Stretchbending

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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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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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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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