Table of Content

    10 September 2022, Volume 33 Issue 17
    Hysteresis and Dynamic Response of Magnetorheological Measuring Systems
    LYU Jingcheng, WEI Yintao, WU Mingyu, HE Junxiang, LIANG Guanqun, YIN Hang
    2022, 33(17):  2017-2023.  DOI: 10.3969/j.issn.1004-132X.2022.17.001
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    The control effectiveness of magnetorheological systems depended on the modeling, which was crucial for modeling hysteresis and dynamic response characteristics. By analyzing the hysteresis of each part of the magnetorheological systems excited by a control signal, the method of systematically studying the dynamic behavior of parts was known. By applying the excitation of DC and AC, dynamic response characteristics of the magnetorheological measuring systems were tested and studied. The results show that the current-shear stress relationship under the excitation of the unbiased harmonic current is a butterfly curve, which is caused by the response hysteresis, and the smooths upper and lower edges of the curve are caused by the hysteresis and the nonlinearity of the system, respectively. Finally, the hysteresis time is introduced to better describe the dynamic response relationship between currents and shear stresses in various situations, and the value is as 23.1 ms. 
    Experimental Research of Surface Quality Evaluation Method for Wire Saw Sapphire Wafer
    WANG Lanqing, HUANG Hui, CUI Changcai
    2022, 33(17):  2023-2028.  DOI: 10.3969/j.issn.1004-132X.2022.17.002
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    Multi-wire sawing was widely used in slicing of hard and brittle materials. Surface quality of sliced wafers had a greater impact on the subsequent grinding and polishing processes. A surface quality evaluation indicator of sliced wafers named MMA was proposed for wire sawing. The measurement principle of MMA was designed, and the implementation plan was given in detail. The influences of processing parameters on MMA at different positions of wire net were analyzed. The results show that the MMA proposed herein may better reflect the influences of wire cutting process parameters on the surface quality of wafers. 
    Study on Diameter Increase Deformations and Machined Surface Quality under Constraints of Side Wall during Jet Cutting
    HAO Yucong, ZHAO Wei, YANG Tao, GUO Peng,
    2022, 33(17):  2029-2037.  DOI: 10.3969/j.issn.1004-132X.2022.17.003
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     When using sodium chloride grain jet to cut biological bone materials, the deformations of the jet beam might cause unexpected damage to the cutting sections of the bone materials, which was not conducive to the later recovery of biological tissue. In order to explore the deformations under the constraints of the side wall during jet cutting and the quality characteristics of the corresponding machined surfaces, a visualization experiment of abrasive water jet cutting was designed. A high-speed camera was used to photograph the abrasive water jet machining processes, the deformations of the jet beam were observed by visual means, and the surface roughness Ra was used to characterize the quality of the machined surfaces. It is found that the jet beam has a diameter-increasing deformation along the cutting feed direction under the joint constraints of the front-end sidewall and the two-side sidewalls, this deformation increases the range and frequency of the reduction in surface roughness along the depth of cut. Finally, through the secondary processing of the change data of surface roughness Ra along the depth of cut, a new idea of establishing the surface roughness prediction model of abrasive water jet cutting material was proposed. 
    Erosion Morphology and Performance Evolution of Full-circumference Hydraulic Slide Valves
    LI Shuanglu, YIN Yaobao, ZHANG Xinbin, WANG Xiaolu, FU Junyong
    2022, 33(17):  2038-2045.  DOI: 10.3969/j.issn.1004-132X.2022.17.004
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    In view of the profile changes of valve port and performance uncertainty of the high-end hydraulic components caused by erosion of the slide valves, considering the probability of particle hitting the valve port, the quantitative calculation method of the erosion fillet of full-circumference opening slide valve was established based on the Edwards erosion model. Combined with the valve-controlled symmetric cylinder systems, the evolution law of four portss profiles and the characteristics of the four-sided slide valve after erosions were obtained. The results show that the erosion fillets are directly determined by the particle size, amount, impact velocity, valve opening and so on. The greater the valve port flowrate, the greater the amount of particles, the greater the pressure drop, the greater the impact velocity. The larger the size of particles relative to the valve opening, the greater the probability of particle hitting valve port. In the valve-controlled cylinders power mechanism, the size, speed and load of the hydraulic cylinder determine the flowrate, pressure drop and opening of the valve ports. Under the conditions of constant load and consistent reciprocating speed of hydraulic cylinders, the flowrate of the four valve ports of the valve-controlled symmetric cylinder is the same but the pressure drop is different, the fillets after erosion are inconsistent. Erosion results in the decrease of the pressure gain and increase of leakage of the slide valve, and the null bias occurs, the null bias displacement may be obtained by the balance principle of Wheatstone bridge.
    Low Frequency Vibration Reduction Method of Ship Floating Rafts Based on Local Resonance
    GUO Peng, ZHOU Qizheng, LUO Ziyin, LI Jian
    2022, 33(17):  2046-2052,2060.  DOI: 10.3969/j.issn.1004-132X.2022.17.005
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    To control the low frequency vibration and noise line spectrums of a ships floating raft under power mechanical excitation, the coupled vibration equations of power machinery-plate-local resonance units were established by the variational principle, and the solution of the coupled vibration equation was derived by the modal superposition method. Then the calculation formula of the radiated sound power level of the plate was given. A small size and lightweight low frequency resonator was designed, and the effects of the locally resonant unit on the control of low frequency vibration and radiation sound power line spectrum of the plate structure were investigated under the excitation of power machinery. The results show that, with the additional mass less than 3% of the plate mass, the average surface velocity level and the radiated sound power level of the plate structures under low frequency vibration line spectrum may be reduced by more than 10%; when the locally resonant unit contains multiple resonators with different intrinsic frequencies, multiple low frequency vibrations line spectrum of the plate structures may be controlled. 
    Low Frequency Vibration Mechanism for AMB High-speed Motor Rotor Systems and Its Compensation Strategy
    JI Li, MA Xueqing, CHEN Zhenmin
    2022, 33(17):  2053-2060.  DOI: 10.3969/j.issn.1004-132X.2022.17.006
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    In industrial applications, a nonsynchronous low frequency vibration occured frequently for high-speed motor systems with AMB. The low frequency vibration was analyzed from two aspects of mathematical model and external excitations. The results show that the low frequency vibration is determined by the natural frequency of the AMB control system, and it is excited by the external noise. Then the compensation strategy was present based on the ESO, and the stability of the AMBs control system was studied. For verification, the simulations and experiments regarding to low frequency vibration were carried out. The results show that under the same white noise excitation, the vibration amplitude of rotor with compensator decreases about 21% compared with that with PID controller. During the speed of 30 000 r/min, the compensator is more effective, and the vibration amplitude of the rotor is reduced by 26.6%. 
    Iterative Optimization and Evaluation Method for Repair Quantity of Aviation Structural Parts Considering Measured Data
    CHEN Shuai, GUO Feiyan, MENG Yuemei, WANG Mingyang, HOU Zhixia
    2022, 33(17):  2061-2070,2078.  DOI: 10.3969/j.issn.1004-132X.2022.17.007
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    Aiming at the problems of low one-time assembly success rates of large aviation structural parts, unpredictable assembly deviations and unpredictable repair quantities, an iterative optimization and evaluation method of repair quantity was proposed based on measured data. With the goal of improving the quality of repairs, the model was reconstructed by integrating the measured data in the assembly processes, and the overall scheme of gradual optimization of repair scheme was proposed. According to the requirements of repair processes, a repair simulation optimization method was proposed based on improved particle swarm optimization algorithm to carry out repair simulation and assembly accuracy prediction, so as to ensure that the assembly accuracy met the requirements first. According to the membership degree theory of fuzzy mathematics, a comprehensive quantitative evaluation of qualitative factors such as repair cost and difficulty was carried out to realize the re-optimization of the repair plans. Finally, taking the position deviation control of the rib bar of a certain type of central wing box assembly station as an example, a software tool for generating a repair plan was developed, and the prediction and repair simulation optimization were carried out before the actual assembly operations. Field applications show that the proposed method may predict the assembly accuracy more accurately, determine an accurate repair plan in advance, and effectively improved the assembly quality and efficiency. 
    Intention Recognition Method of Human Robot Cooperative Assembly Based on EEG-EMG Signals
    DONG Yuanfa, JIANG Lei, PENG Wei, ZHOU Bin, FANG Zifan
    2022, 33(17):  2071-2078.  DOI: 10.3969/j.issn.1004-132X.2022.17.008
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     Aiming at the problems of low accuracy and poor stability of identifying cooperative intention based on single source physiological electrical signals in human robot cooperative assembly scene, firstly, support vector machine was used to recognize single source cooperative assembly intentions from EEG and EMG signals respectively, and then D-S evidence theory was used to fuse the recognition results of multi-source cooperative assembly intentions. A human robot collaborative assembly intention recognition method was proposed based on EEG-EMG signals. Experimental results show that the proposed method may effectively improve the accuracy and stability of human robot cooperative assembly intention recognition. 
    Design and Performance Evaluation of Amphibious Hexapod Robots
    WANG Yu, ZHOU Shuang, LI Yaxin
    2022, 33(17):  2079-2086.  DOI: 10.3969/j.issn.1004-132X.2022.17.009
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    In order to improve the motion performance of the robots in amphibious environment, and to reduce the mechanical complexity and control difficulty of their motion mechanism switching between water and land, an amphibious hexapod robot with compound moving limbs was proposed. Through the land and underwater motion planning of the robots, the stability problem of the robot adapting to different slope terrain was solved. The multi-degree-of-freedom underwater motions of the robots were realized by configuring the positions and poses of the vectored propeller. The simulation results of the robots crawling motion under ADAMS verify that the mechanical design of the robost is reasonable, and also show that the robots have good stability when climbing on different slopes. In order to further evaluate the motion performance of the robots, a prototype robot was built to test the climbing performance of the robots on the slope, and at the same time, the multi-degree-of-freedom motions of the robot under water were verified, including straight, rotating, floating and diving. The experimental results show that the robots have good motion performance both on land and underwater. 
    Research Status and Development of Hybrid Additive Manufacturing Technology
    XIONG Xiaochen , QIN Xunpeng , HUA Lin , HU Zeqi , JI Feilong ,
    2022, 33(17):  2087-2097.  DOI: 10.3969/j.issn.1004-132X.2022.17.010
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    The poor forming accuracy and performance restricted the development and applications of metallic additive manufacturing technology. Hybrid additive manufacturing had a significant effectiveness on solving the problem. The classification and main categories of hybrid additive manufacturing technology were highly generalized herein. The research progresses and technical developments of additive and subtractive hybrid manufacturing in the control of the part forming accuracy and surface quality were briefly summarized. The technology categories, forming principles, manufacturing characteristics and key problems of additive and equivalent hybrid manufacturing were emphatically commented, as well as the research status and main conclusions of additive and equivalent hybrid manufacturing on the control of microstructure, stress state and macro-performance of the parts. The acting mechanism of three special auxiliary energy fields, namely ultrasonic, electromagnetic and laser, on the flow, crystallization and solid-state phase transition of additive molten pool, and the evolution law of microstructure state, mechanical properties and forming accuracy of additive layer under the action of special energy fields were systematically introduced. Finally, the development trends of hybrid additive manufacturing technology were prospected in the future. 
    Subtractive Post-machining Allowance Optimization Considering Characteristics of DEDs
    HOU Liang, GUO Jing, CHEN Yun, YE Chao, XU Yang, ZOU Jiahao
    2022, 33(17):  2098-2106.  DOI: 10.3969/j.issn.1004-132X.2022.17.011
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    Complex free-form parts manufactured by DED had problems of uneven allowance distributions and severe stair-case effects. In order to optimize allowances for subtractive post-machining, a dynamic point cloud registration method using the mid-surface points of the deposited and theoretical parts was proposed to optimize the machining allowances, which took into consideration characteristics of the DED parts. Firstly, the section line of the minimum outer envelope of deposited complex free-form parts was constructed according to the deposition scanning path, and was used for obtaining the point cloud of the on-machine measurement. Secondly, the mid-surface points of the deposited and theoretical parts were extracted, and an iterative closest point with dynamic weights considering the multi-region allowance requirements was proposed to optimize the machining allowances. The feasibility of the algorithm was verified by two simple cases. Finally, a free-form blade of a centrifugal impeller was selected as a complex case for allowance optimization. The proposed method was also compared with the method for multi-region allowance using genetic algorithm. The results show that the proposed allowance optimization method is more accurate and efficient for rapid optimization of machining allowances for DED manufactured complex curved parts. 
    Finite Element Simulation and Experimental Study of Grinding Holes of SiC Ceramic Rotary Ultrasonic Vibration Trepanning Drilling
    DONG Xianglong, ZHENG Lei, SONG Chunyang, LYU Dongming, XU Subai, WEI Wendong, QIN Peng
    2022, 33(17):  2107-2114.  DOI: 10.3969/j.issn.1004-132X.2022.17.012
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     In order to solve the problems of edge chipping and cracking in the machining of SiC ceramics, a combination of simulation and experiment was used to study the technology of grinding holes in the rotary ultrasonic vibration trepanning drilling. According to the macroscopic mechanics constitutive model of SiC ceramics, the finite element models for the SiC ceramic hole making simulation were established and the simulation analysis of the machining processes was carried out. Compared with the conventional hole making, the simulation axial forces of the ultrasonic vibration hole making may be reduced by 26.1%. The comparative experimental study of conventional machining and ultrasonic vibration machining shows that rotary ultrasonic vibration machining may reduce the axial force by 32.9%, greatly reduce the brittle fracture of ceramic materials, and significantly improve the surface quality of the hole walls. Under ultrasonic vibration conditions, the maximum difference between the axial force values obtained by finite element simulation and experimental research is as 7.5%, and the maximum difference under normal conditions is as 14%, which verifies the correctness of the finite element model. Simulation and experimental results show that ultrasonic vibration machining may significantly reduce axial forces and tool wear, improve tool durability, improve hole quality, and save machining costs. 
    Simulation Analysis of Temperature Fields and Parameter Optimization of Stationary Shoulder Friction Stir Welding
    ZHANG Jun, WANG Wen, WANG Jian, JIN Taotao, TIAN Zhipeng
    2022, 33(17):  2115-2124.  DOI: 10.3969/j.issn.1004-132X.2022.17.013
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     In order to solve the problems of welding failures caused by the traditional stirring head which easily fell into the welded plates under the conditions of non rigid support, the stationary shoulder welding structure was designed and developed. By establishing the finite element simulation model and using the thermal infrared imager to monitor the welding surface temperature in real time, the changes of temperature fields during stationary shoulder friction stir welding under different processing parameters were analyzed. The stationary shoulder friction stir welding designed and developed were used for field tests, and the tensile tests were carried out to compare the welds without defects on the welded surfaces with the base metal, the mechanical strength of the welds was detected, and the microstructure of the fracture was analyzed. The results show that in the welding processes of stirring head with stationary shoulder, the heat generation mainly comes from the friction heat generated by the shoulder and the end of the stirring needle, and the side friction heat generated by the stirring needle and the friction heat generated by the stationary shoulder account for a small proportion. The spindle pressure and spindle speed have great influences on heat production, and the C-axis speed has little influences on heat production. Under the processing parameters of spindle pressure of 2940~3430 N, spindle speed of 1000 r/min and C-axis speed of 0.05 r/min, the surface of the welded seams is smooth without flash, there are no groove and tunnel defects inside, the tensile property of the welds reaches about 71.5% of the base metal. There is delamination in the weld fracture. The upper layer near the welding surface shows brittle fracture characteristics, and the lower layer shows ductile fracture characteristics. Compared with the base metals, the elongation and tensile strength of the weld specimens are reduced. 
    Experimental Investigation on Comprehensive Performance Comparison for Rail Grinding Using Abrasive Belt and Abrasive Wheel
    WU Zhiwei, FAN Wengang, WANG Qian, LIU Yi, MA Tengfei,
    2022, 33(17):  2125-2132.  DOI: 10.3969/j.issn.1004-132X.2022.17.014
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    Based on the self-developed lithium battery-driven rail abrasive belt and abrasive wheel grinding machine, the 60N rail profile was used as the experimental objects to comprehensively compare the performance of the new rail belt grinding technology and the traditional grinding wheel grinding technology. The results show that when the grinding pressure is in the range of 45 to 75 N, the material removal rate of abrasive belt grinding is about 15 to 30 times that of abrasive wheel grinding, while when the pressure is increased to 90 N, the material removal rate of abrasive belt grinding is as high as 102 times that of abrasive wheel grinding. The vibration acceleration, noise and energy consumption of abrasive belt grinding are less than that of abrasive wheel grinding. The abrasive belt grinding chips are banded, while the abrasive wheel grinding chips are molten at high temperature. At the same time, when the grinding pressure is increased to 105 N, the rail surface will turn blue after grinding, but the abrasive belt grinding will not. In addition, the lateral surface roughness of abrasive belt grinding is greater than that of abrasive wheel grinding, up to 8 μm, which meets the maximum 10 μm required by Chinese railway rail maintenance. To sum up, rail abrasive belt grinding technology is significantly superior to traditional abrasive wheel grinding technology in material removal rate, vibration, noise, energy consumption and temperature, etc. It is expected to be one of the effective methods to solve serious rail diseases in engineering practices. 
    Research on Mechanism of Rock Breaking and Speed Increase in Cutting with Abnormal PDC Cutter
    LIU Weiji, YANG Feilong, ZHU Xiaohua, LUO Yunxu, HELing
    2022, 33(17):  2133-2141.  DOI: 10.3969/j.issn.1004-132X.2022.17.015
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    A tri-dimensional finite element numerical simulation model for cutting heterogeneous granites with specially-shaped cutter and full-sized bits was established based on the indoor cutting experiments. The values of tangential force, normal force, rock debris and MSE in the cutting processes of heterogeneous rocks with 12 kinds of PDC cutters were discussed, and the influences of cutter shape on rock-breaking efficiency of full-sized bits were also studied. The research results show that the tangential force of the conical cutter is the smallest, the MSE is the highest, and the footage of the corresponding conical cutter bits is also the smallest. Among all the cutters, the normal force and tangential force of the tri-planar cutters are the largest, while the MSE hyperboloid-shaped cutters is the smallest. Bits with saddle-shaped cutter, hyperboloid-shaped cutter or axe-shaped cutter which are easier to penetrate into rocks are able to have larger footage.