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Table of Content

    10 December 2015, Volume 26 Issue 23
    Applications of Multiple Leaders DMPSO in Hydraulic APC System of Cold Strip Mill
    Wei Lixin, Wang Liping, Xu Deshu, Lin Peng, Yang Jingming
    2015, 26(23):  3125-3129. 
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    According to the characteristics that the parameters of cold rolling hydraulic APC system changed over time, which was a dynamic system. This paper proposed a strategy for PID controller parameters setting based on improved DMPSO algorithm. This strategy might set and optimize PID controller parameters in real time through the ability of dynamic multi-objective particle swarm optimization algorithm that adapted environment changes and optimized. Meanwhile, to avoid falling into local optimum and slow convergence speed, a DMPSO was put forward based on multiple leaders in guiding the particles search.Simulation results show that the control system with fast track, small overshoot and strong adaptability is better than the traditional PID control.

    Car Body Design Based on Quartic Generalized Bézier Surfaces with Multiple Shape Parameters
    Guo Lei, Zhang Chunhong, Hu Gang
    2015, 26(23):  3130-3133,3139. 
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    A method for car body design was proposed herein based on quartic generalized Bézier surfaces with multiple shape parameters, which described the car body with the groups of quartic generalized Bézier surfaces with multiple shape parameters. Firstly, a group of quartic generalized Bézier surfaces were created and blended continuously; the surfaces' boundary position and the shape parameters were adjusted and then a new car form could be obtained. This method, based on the principles of the quartic generalized Bézier surfaces with multiple shape parameters generation and blending, can modify the surfaces quickly by the boundary curve adjustment and obtain many design solutions.

    Electromechanical Coupling Modeling and Simulation Analysis of Scraper Conveyor System
    Zhang Qiang, Wang Haijian, Mao Jun, Liu Zhansheng
    2015, 26(23):  3134-3139. 
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    According to the coupling relationship between the mechanical system and control system of scraper conveyor, the nonlinear state space electromechanical coupling equations were derived for scraper conveyor, the simulation model of the scraper conveyor was established by using MATLAB/Simulink  module, the electromechanical coupling dynamics of the scraper conveyor system was studied, the equivalent load change of mass was used to  analyse the scraper conveyor's scraper chain speed and electromagnetic torque characteristic curves in no-load start, stable operation, load surge and card chain condition.Two sprockets' angle curves were obtained at startup, the results show that, the start angle difference between drive sprocket and the driven sprocket is about 85°, the driven sprocket lag about 0.8s than  that of drive sprocket when it rotates.It is provided the theoretical and numerical basis for studying scraper conveyor's torque,speed change and calculation of sprocket's pretension in different working conditions and loads. 

    Research on Dynamic Bulging of Continuous Casting Slab Based on Elasto-viscoplastic Behavior of Metal at Elevated Temperature
    Hai Peipei, Ren Tingzhi
    2015, 26(23):  3140-3145. 
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    Based on elasto-viscoplastic behavior of metal at elevated temperature, a mathematical model of dynamic bulging with the movement of the slab between two rolls was developed. According to different initial conditions and the deformation history of a solidified shell, two groups of boundary conditions were presented. Then, in order to check the validity of this mathematical model, the calculated bulging profiles were compared with the measurements of bulging intensity and profiles on actual continuous casters. Then according to the casting parameters on different segments of an industrial caster in Ansteel company, the bulging of the solidified shell near mould and far from mould were exposed separately. In addition, the bulging features were analyzed including the bulging deflection, the bending moment acting on the solidified shell, the strain and the strain rate at the solid-liquid interface of the solidified shell. Finally, the bulging in a segment of the caster was calculated, and then the influences of the casting parameters including roll pitch and casting speed were analyzed.

    Bayes  Model of  Exponential  Product  Multi-stage  Reliability  Growth
    Yu Chunyu, Su Zimei, Sun Yongquan, Yuan Jiahe, Niu Bin
    2015, 26(23):  3146-3155. 
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    A multi-stage   reliability  growth  Bayes  model  was  built based on  D-S  evidence  theory and prior information,  that  was  adaptive  to  small-sample complicated  systems.Gamma distribution was used as prior distribution of failure rate.Through integrated usage of multiple-source  reliability informations,the  expertise  was converted into probability distribution.Using D-S evidence theory and multiple experts' informations,the prior distribution parameters were known.With  test  data  at  product  development  and  Bayes  statistical inference theory,the  failure rate,MTBF,point estimation and lower confidence were obtained.The  validity of this approach was illustrated by the development  and  test  of  MW  direct-drive  wind turbine.

    Modeling and Simulation of Hydro-vibration System Assisted by Variable Inertia Flywheel Pulsation
    Lü Yunsong, Guo Junzheng, Ke Guangyun
    2015, 26(23):  3150-3155. 
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    A hydro-vibration system assisted by variable inertia flywheel pulsation was put forward. An ordinary hydro-vibration circuit was coupled with an assistant circuit consisting of a variable inertia flywheel, a hydro-motor and a hydro-bridge. The flywheel produced a pulsating rotation by means of its moment inertia change and rectification with bridge, a momentum circulation between the flywheel and the vibrator was thus brought about to boost vibration. The mathematical model of the system was built, and the energy efficiency analyses for the momentum cycle were carried out. Theoretical analyses and MATLAB simulation show that the vibration performance is related to the frequency characteristics of the system and the dynamics of the flywheel. By rational choice of mechanical parameters and control modes of the loop, the obvious vibration and energy saving effect can be obtained.

    An Approach to Adaptive Response Surface Optimization of One-side Pressed Drilling Process
    Jiang Liping, Chen Wenliang, Wang Min, Liu Yuling, Hou Yuzhao
    2015, 26(23):  3156-3161. 
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    A parameter optimization of automatic one-side pressed drilling process was presented to solve the key technology of one-side pressed drilling process based on the adaptive response surface methodology (ARSM), which was applied by the light-weight automatic drilling system. This method might construct reliable response surface by finite element simulations of a few samples, and might avoid the finite element simulation in every iterative optimization. So it might improve the computational efficiency and accuracy greatly.The adaptive response surface was constructed by a case study of joint structure between the frame of fuselage sections, Then the optimized parameters of drilling were achieved through adaptive response surface methodology. The optimized results show that the press forces over or less the optimum values will cause the exaggerated gap of contact surface, so the processing key is to apply reasonable press forces.The effectiveness of the method was verified by the experimental results.

    Stiffness Improvement of 3RPS PKM by Redundant Actuating Leg
    Cui Xueliang, Chen Wuyi, Han Xianguo, Zhu Xijing, Wang Jianqing, Cheng Quan
    2015, 26(23):  3162-3167. 
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    Considering the relationship between the changes of the Jacobian matrix and the orientation deviation of the moving platform, the mapping model between the 3RPS PKM end-effector offset and the deformation of the branches was established by using the vector differential method, based on the screw theory. The functional expression of the rigidity of the chain and its components was derived, and then the instant stiffness model of the 3RPS PKM was built up. The influences of the changes of the Jacobian matrix on the stiffness of the PKM were analyzed. The theories that the redundant actuating leg could increase the stiffness of the PKM were discussed, and were also verified by the simulation and the tests.

    Variable Step Size Optimizing Method of Rotor Dynamic Balance Based on Fuzzy Control
    Zhang Li, Chen Shizhen, Xu Juan, Niu Qingbo
    2015, 26(23):  3167-3171. 
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    Automatic optimization control was one of the methods in rotor dynamic balancing which was studied extensively currently, but its balance precision was limited, and the balancing time was long, so there were many limitations in practical applications. Considering the above problems, aiming at the single-plane dual counterweight block dynamic balancing device, a rotor dynamic balancing control strategy was proposed herein, which calculated the step size by fuzzy control and completed the balancing process by variable step size optimizing method. A self-designed rotor test rig was built with the measure-control system for experimental verification, and the results prove that the control strategy improves the balance precision and efficiency obviously compared with the traditional automatic optimization control method.

    Material Selection of Automotive Components Based on Information Axiom with 2-Tuple Linguistics
    Wang Haolun, Xu Xiangbin, Zhou Ermin
    2015, 26(23):  3172-3177. 
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    To deal with the problems that evaluation informations were subjective and uncertain in automotive component material selection processes, an automotive component material selection approach based on information axiom with 2-tuple linguistic was proposed. Firstly, the method converted the linguistic assessment informations of each expert to 2-tuple linguistic, the group's 2-tuple linguistic decision matrix and the attribute weight vector were calculated according to the 2-tuple linguistic aggregation operator, and the attribute combination weight vector was determined. Then the 2-tuple linguistic information contents of automotive component materials were calculated based on information axiom, consequently, the rank results and selection of automotive component materials were obtained with information contents. Finally, an example of material selection for instrument panel shows the effectiveness and feasibility of the proposed method.

    A New Numerical Simulation Method  for  Calculating  Fatigue  Damage  of  Wheels
    Dong Yun, Feng Ruicheng, Yan Changfeng, Duan Zaoqi
    2015, 26(23):  3178-3183. 
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    According to the  characteristics of the complicated structure and cyclic loading  of wheels,a  new numerical simulation method for calculating fatigue damage of  wheels  was  proposed  based on two ways,one was the fatigue damage coupling theory of strain equivalence and the finite element analysis method,the  other was the law of material fatigue damage and the rigid method. Combining constants and properties of the fatigue damage model with fitting,a subroutine to calculate damage and to predict fatigue life on ANSYS platform was developed, while the initiation and growth of cracks of rim were simulated by damage developing, the crack propagation paths were  given under the different cycles as the fatigue life was  obtained.At last,the comparison between fatigue tests and calculation results indicates that this method is proper,feasible and of high accuracy.

    Adaptive Characteristic-scale Decomposition Method and Its Applications
    Wu Zhantao, Cheng Junsheng, Yang Yu
    2015, 26(23):  3184-3191,3199. 
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    Based on the research of  LCD,this paper borrowed ideas from the sifting based signal decomposition methods such as EMD   and LCD,and then presented  a new mono-component signal with physically meaningful instantaneous frequencies, i.e.,ICC,for  restraining the mode mixing problem of LCD and improving the deficiency in terms of the mean curve definition. Finally, a new signal decomposition method,ACD was proposed.Meanwhile, the evaluation criterion of  ICC was also given.In the sifting procedure for separating certain order components,a  set of ICCs was obtained by using different mean curves and compact coefficients. The optimal ICC for this order sifting would  be selected from the candidate ICCs using the evaluation criterion of ICC, which guaranteed  ACD outperforms LCD.The simulation results indicate that the decomposition effect of ACD is better than  that  of  EMD,LCD,ensemble empirical mode  decomposition(EEMD) and autonomous compact local characteristic-scale decomposition(ACLCD),  experimental  results  of  the experimental signals show its validity.Thus a new way for fault diagnosis of rotating machinery is provided.

    Iterative Adaptive Multiscale Morphological  Filtering-based  Fault  Diagnosis  for  Rolling Bearings
    2015, 26(23):  3192-3199. 
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    Aiming  at the problems  of extracting characteristics from vibration signals in the intense industrial background noise and the blindness and randomness of single scale morphology filter in scale selection,a novel filtering method of iterative adaptive multiscale morphology analysis(IAMMA) was proposed. The method was based on adaptive multiscale morphology analysis (AMMA). In order to filter out noise components,the multiscale morphological difference iteration was used to process the signals with gradually increase structure elements.Then, the average value of multiple filtering reaults was calculated. Furthermore, the simulation signals and fault signals of the rolling  bearings  were analyzed. The results demonstrate that, comparing with AMMA,the  IAMMA can  select  better scale and extract more feature information and get better filtering results. Moreover, comparing with Hilbert, the processing procedure of IAMMA is more simple. It is  a valid method for fault  diagnosis of rolling bearings.

    Research on Flexible Job-shop Scheduling Problem with Consideration of Batch Splitting and Assembly
    Ba Li, Li Yan, Cao Yuan, Yang Mingshun, Liu Yong
    2015, 26(23):  3200-3207. 
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    FJSP was a quite important combinatorial optimization problem in the field of production scheduling. Because of the one-to-one relationship among processes and machines was canceled in FJSP, FJSP was more complex than job-shop scheduling problem (JSP). Aiming at the shortages of FJSP in batch and assembly, batch factor and assembling processes were integrated in FJSP simultaneously. Makespan of finished product was the main target which will be optimized. A particle swarm optimization (PSO) with a multi-layer encoding structure was proposed. Each module of the PSO was designed. Finally, the model and algorithm were proved through an application case.

    Feature Extraction Method of 1.5-dimensional Faced to Running Stability Deterioration of Rotating Machinery
    Jiang Zhanglei, Xu Xiaoli
    2015, 26(23):  3208-3213. 
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    Wind turbines were typical large rotating machinery with variable conditions and non-stationary states, and vibration signal energy was changed because of non-fault factor such as variable conditions and loads. Fault diagnosis method based on vibration signal energy such as vibration level and power spectrum method could not extract running stability deterioration features from non-stationary signals under the influences of variable conditions and loads. 1.5-dimensional spectrum feature extraction method was studied based on higher-order cumulant method,and an evaluation method was proposed by using sensitivity property, trend property, difference property, and consistency property. Experimental data of varying degrees of deterioration under various types of deterioration were carried out to validate the proposed method, and the results show that feature extracting method can separate the deterioration characteristics from non-degradation characteristics, and the evaluation method can provide theoretical basis for selecting feature extraction method for fault diagnosis and trend prediction of running stability deterioration.

    Research on Bearing Behaviors of Printing Cylinder Based on Preload Elastic Supporting
    Yao Qishui, Li Chao, Wang Yong, Yu Jianghong, Yang Wen
    2015, 26(23):  3214-3220. 
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    When the printing cylinder was in operations the excessive deflections were easily result in deficience of printing pressure in contact zone and affect the quality of the prints. From the perspective of improving the supporting property of printing cylinder, preload elastic composite cylindrical roller bearing was treated as parts of carrying load of printing cylinder. By means of numerical simulation software ANSYS, the filling degree of preload elastic bearing was optimized, the influences of preload elastic bearing interference on the deflection of printing cylinder under the conditions of working load were studied, the overpressure protection of printing cylinder under the conditions of overpressure load were discussed, finally, the invalidation of preload elastic bearing were analyzed. The results show that preload elastic bearing can reduce the deflection of the printing cylinder effectively under circumstance of withstand working loads and the printing cylinder can produce deflection to relieve the damages of itself and accessories under circumstance of sustain overpressure loads.

    Influencing  Factors  of  Joining  Aluminium  and  Composite Sheets  with Rolling  Riveting
    Huang Zhichao, Zhang Yongchao, Peng Xilin, Guan Changhai, Lai Jiamei, Zhou
    2015, 26(23):  3221-3227,3259. 
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    Through rolling riveting and tensile tests of aluminum and composite sheets, this paper analyzed the influences  of gasket,different reserved heights of rivets and apertures on connection quality. The results show that the most affects on tensile properties are gaskets, and the bearing capacity of test piece with gasket may be updated by around 50%. Reserved heights have a certain affect on connection performance. Tensile properties declines with increase of rivet height. Bearing capacities are almost the same when the height is as  1.0mm or 2.0mm.Aperture has little effect on connection quality. The test results of 6.0mm apertures are better than these of 5.9mm and 6.1mm apertures. Mechanism of connection performance promotion was  explained in aspect of microstructure through metallographic test for specimen with steel rivets. The same tests were conducted by using copper and aluminum rivets, and the results are similar. Corrosion tests of different times show that the corrosion of sulfuric acid solution has little effect on tensile properties in a short period of time.

    Strength  Design  and  Structural  Optimization of  Cold  Extrusion  Die  for  Cylindrical  Workpieces
    Lu Zhibing, Wang Chengyong, Zhang Xinyi , Zhang Peng, Wang Siyan, Wang Yuan
    2015, 26(23):  3228-3233. 
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    Based on the theories of thick-walled cylinder, the mechanical characteristics of integral die under working conditions were analyzed and the  calculation  results  show  that it  is  difficult to increase the die strength only by increasing the wall thickness. In order to improve the load supporting capacity of the die, the scheme of prestressed multilayer the die was discussed. Based on the fourth failure criteria,a mathematical expression of n-layer combinatorial die under internal pressure was deduced. Lagrange multiplier method was used to obtain the optimum design parameters of combinatorial die. The design formulas of optimum diameter ratio of each layer, the limit loading pressure,the residual pressure in shrinkage interface and optimum radial magnitude of interference were investigated. Through the optimum design of three-layer combinatorial die, the derived formulas was verified using two methods of theoretical analysis and numerical simulation.The investigation shows that the simulation results are consistent with the theoretical ones.

    Robust Design Optimization for Stamping Based on Parametric and Metamodel Uncertainty
    Li Kai, Yang Xujing, Zheng Juan
    2015, 26(23):  3234-3239. 
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    In traditional metamodel-based stamping robust design, due to the errors between metamodel and real model, there were certain design errors in the optimization results. Combining experimental design with Kriging model and considering both parametric and metamodel uncertainty, a new robust design method was established herein. The agent models of design parameters and quality index were built, and the Monte Carlo simulation method was combined with genetic optimization algorithm to obtain the optimal process solutions. The results show that compared to the traditional design method, the proposed method can effectively reduce the probability of crack and wrinkle constraint failure, and improve the forming quality and process robustness.

    Mechanics Analyses on Hot Granule Medium Pressure Forming Process for AA7075-T6 Cylindrical Parts
    Yuan Rongjuan, Yang Shengfu, Zhao Changcai, Dong Guojiang
    2015, 26(23):  3240-3248. 
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    Based on the pressure-transfer performance test of granule medium and the material performance test of AA7075-T6 sheet, plastic mechanics analyses were conducted for the flange area, force-tranfer area and free deforming area in the forming process of cylindrical parts by hot granule medium pressure forming(HGMF) process. The function relation of forming pressure was obtained under the conditions of internal pressure nonuniform distribution, and compared with test data, the results show that the larger deviation occurs in the middle and later period of forming and the theoretic maximum forming force is less than the test data by 24.6%. The results of processing test show that the limiting drawing ratio of AA7075-T6 cylindrical part(the bottom is free forming area) formed for one time by HGMF process is 1.71. The HGMF process has convenient operation and simple apparatus, and it can realize the hot forming on light alloy sheet in the general pressure equipment. This process is suitable for the small batch of products in the field of aviation, spaceflight and military industries.

    Modeling and Simulation of Commercial Vehicle Fuel Economy Based on Vehicle Speed Tracking
    Li Gangyan, Shi Huiping, Tu Ming, Hu Jian, Niu Ziru
    2015, 26(23):  3248-3252. 
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    Most of  the fuel economy simulation models can only calculate fuel consumption of the vehicle in modal cycles.To solve the problem,a new method for commercial vehicle fuel economy modeling method was proposed based on longitudinal vehicle speed tracking.On the premise of the establishment of vehicle longitudinal dynamics model,driving intention model,engine and transmission system model,a commercial vehicle fuel economy simulation model was built with MATLAB/Simulink.Taking a bus as an example,a comparison was made between vehicle test and model simulation,the results of which show that:the simulation model can follow any driving cycle of commercial vehicle very well,and calculate the commercial vehicle fuel consumption in the driving cycle accurately.By changing the vehicle related parameters in the simulation model, simulation of fuel economy for commercial vehicles with various powertrain configuration can be carried out conveniently and quickly.

    Analyses of Transmission Error of Mechanical Shift Gear in HMCVT
    Lei Xianqing, Cai Zhenhua, Zhang Mingzhu, Ma Wensuo
    2015, 26(23):  3253-3259. 
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    Based on the mechanical shift gear in HMCVT of Dongfanghong,the rules of the transmission error changing with time were researched to reduce the power loss of the transmission. The formula among transmission errors of planetary gear set, fixed-axle gear pair,the two factor function simultaneously and time were established by using the theory of equivalent mesh error. The gear which had the transient maximum and the minimum transmission errors and the dominant factor of transmission errors were found by comparing the whole transmission error and the transmission errors of planetary gear set. There existed coupling relationship among the transmission errors of planetary gear set and fixed-axle gear pair when the angular frequency was the same. The correctness of the rules was verified by using the Monte-Carlo method. The formula among transmission errors and power loss was established. It turns out that there is positive relationship among them. The measures which reduce the power loss of transmission were put forward by using the method which was used to reduce the transmission errors.

    Planetary Cage Structure Optimization of Caterpillar Based on Running Simulation Test
    Liu Zhe, Tao Fenghe, Jia Changzhi
    2015, 26(23):  3260-3265. 
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    Planetary cage was an important part in caterpillar, and it was designed with the static strength theory within limitation of tests and experimental methods. Thus the actual dynamic characteristics of planetary cage could not be embodied, and it brought difficulties to predict life with given dynamic loads and the results were in wide gap between actual life and designed one. A virtual running test platform was built based on ADAMS.ATV, and the dynamic load suffered by planetary cage in different working conditions was obtained. Then the fatigue life of planetary cage was analyzed with fatigue life prediction model of planetary cage established with MSC.Fatigue. The fatigue models of the side reducer were established, and the fatigue life of the planetary cage was obtained, thereby the structure of the planetary cage was improved, the fatigue life of the planetary cage was predicted with the variation of the structural parameters, the planetary cage for structural optimization was explored.