Table of Content

25 April 2020, Volume 42 Issue 4 Previous Issue    Next Issue

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Engine Start-up H∞ Robust Optimal Control of the Compound Power-Split System Zhao Zhiguo, Fan Jiaqi, Jiang Lanxing, Tang Xuhui, Fu Jing 2020, 42 (4):  417-424.  doi: 10.19562/j.chinasae.qcgc.2020.04.001 Abstract ( 335 )   PDF (2619KB) ( 772 )   Save To improve the vehicle ride comfort during switching from pure electric mode to e-CVT mode of the compound power-split hybrid system, while ensuring the robustness of switching control under the conditions of model uncertainty and external disturbance, an engine start-up H∞ robust control strategy is proposed. Firstly, a dynamic model of the compound power-split hybrid system is established, and the switching process from pure electric mode to e-CVT mode is analyzed. Secondly, an optimal crank curve of engine speed is designed based on dynamic programming taking vehicle ride comfort and engine start-up time as optimization indexes. Then, considering the damping perturbation of input shaft, the uncertainty of driver input, road load and output speed, as well as the disturbance of measurement noise, an engine start-up H∞ robust controller is developed. Finally, offline simulation and bench test are conducted to verify the proposed strategy. The results show that the strategy can effectively reduce the vehicle jerk to below 11.52 m/s3, and has strong ability to restrain the model uncertainty and external disturbance References | Related Articles | Metrics

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Division and Optimization of Driving Modes of Electric Vehicleswith Dual-motor Coupling-propulsion Powertrain Lin Xinyou, Wu Jiayun, Wei Shenshen 2020, 42 (4):  425-430.  doi: 10.19562/j.chinasae.qcgc.2020.04.002 Abstract ( 426 )   PDF (4687KB) ( 881 )   Save To give full play to the energy saving advantage of the multi-drive mode of an electric vehicle equipped with dual-motor coupling-propulsion powertrain (DMCP-EV), a driving mode control strategy based on optimal system efficiency is worked out. According to the configuration of DMCP, four driving modes are defined and their dynamic driving models and system efficiency model are established respectively. On the premise of meeting the requirements of power performance, the operation ranges of four driving modes are analyzed and divided. With the system efficiency as optimization objective, an optimization is conducted by using particle swarm optimization algorithm, and an optimal strategy for driving mode switching and torque distribution is obtained. Finally, a validation is performed by both Matlab/Simulink simulation and hardware-in-the-loop experiment. The results show that the driving mode with system efficiency optimized can effectively enhance the energy economy of DMCP-EV, with its energy consumption reducing by 11% while meeting the requirements of power performance References | Related Articles | Metrics

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Research on Coordinated Control of Hybrid Electric VehicleBased on Compensation Sliding Mode Control Cai Yingfeng, Dou Lei, Chen Long, Shi Dehua, Wang Shaohua, Zhu Zhen 2020, 42 (4):  431-438.  doi: 10.19562/j.chinasae.qcgc.2020.04.003 Abstract ( 290 )   PDF (791KB) ( 503 )   Save Considering the structural advantages of the hybrid electric car with planetary-gear-based compound power split system, the hybrid electric car with double-planetary-gear-based compound power split system has become the focus of research of various institutions. The process of switching from electric mode to hybrid drive mode involves the starting of the engine and the intervention of the engine torque. Due to the hysteresis of the torque transient response of the engine, there will be large fluctuation of the output torque of the power system during the switching process. In this paper, to reduce the fluctuation and the dynamic impact in the process of mode switching, a compensation sliding mode control method is proposed for the coordinated control of the hybrid electric car with double-planetary-gear-based compound power split system. Firstly, a dynamics model for the vehicle is built to analyze each mode of the switching process. Then, for the engine drag phase and the hybrid drive phase, the compensation control and the adaptive sliding mode control based on fixed boundary layer are used respectively, and the stability of sliding mode control is analyzed. Finally, the verification simulation is conducted on Matlab / Simulink software platform. The simulation results show that the compensation sliding mode coordinated control strategy can effectively reduce the torque fluctuation and impact in the process of switching from electric mode to hybrid drive mode References | Related Articles | Metrics

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Lean Burn Engine Retrofit Design and Timing Strategy Optimization Yang Jing, Luo Xianfang, He Liange, Tao Wenzhu, Zhao Chao 2020, 42 (4):  439-444.  doi: 10.19562/j.chinasae.qcgc.2020.04.004 Abstract ( 215 )   PDF (2136KB) ( 375 )   Save Based on a high-speed gasoline engine, the combustion chamber structure, fuel injection characteristics and cam profile are redesigned as a lean burn engine. A research method of timing strategy analysis and optimization using response surface model is proposed and the process of multi-objective optimization calculation by using response surface is established. To improve the effective power and reduce the effective fuel consumption rate, the engine performance and response surface coupling optimization model is established by taking ignition timing, air-fuel ratio and intake and exhaust timing as design variables. The analysis and test results show that compared with standard mixture ratio combustion, with reduced inlet and exhaust advance angle and advanced ignition timing, the minimum fuel consumption of the lean-burn engine is reduced by 3.9% and the maximum power is increased by 9.7%; at the same time, the method of response surface optimization improves the optimization efficiency References | Related Articles | Metrics

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Estimation of Charge Transfer Resistance of Lithium Ion BatteryUnder Different Temperature and State of Charge Li Rikang, Wang Xueyuan, Dai Haifeng, Wei Xuezhe 2020, 42 (4):  445-453.  doi: 10.19562/j.chinasae.qcgc.2020.04.005 Abstract ( 272 )   PDF (3916KB) ( 833 )   Save Combining the pseudo-two-dimensional model and the aging mechanism of the lithium ion battery, an electrochemical model is built. Based on the model, a conversion method of the charge transfer resistance at different state of charge and temperatures is proposed. The corresponding charge transfer resistance is obtained from the electrochemical impedance spectra of different temperatures and state of charge after four different aging cycles and the conversion method is used to convert the charge transfer resistance at different conditions. The results show that the average error of the conversion is less than 9%. It provides a new idea for battery life state estimation by using the charge transfer resistance at different temperatures and state of charge References | Related Articles | Metrics

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Study on Mechanism of Internal Micro-short Circuit in EV Li-IonBattery Caused by Mechanical Failure of PP Separator Li Zhijie, Chen Jiqing, Lan Fengchong, Yang Wei 2020, 42 (4):  454-461.  doi: 10.19562/j.chinasae.qcgc.2020.04.006 Abstract ( 244 )   PDF (4546KB) ( 424 )   Save The lithium-ion batteries for electric vehicle in the course of work will withstand the coupling of mechanical, electrical and thermal effects, in which mechanical abuse is one of the most important risks leading to the internal short circuit of lithium-ion batteries, which is likely to result in serious fire accidents. The mechanical integrity of separator is a key factor in preventing the internal short circuit of lithium-ion battery under the condition of mechanical abuse. Through comprehensive mechanical tests, it is found that different sizes of punches will lead to two distinct deformation and failure modes of PP separator. Finally, the mechanism of triggering internal micro-short circuit in lithium-ion battery is analyzed and a critical displacement criterion of separator under the internal micro-short circuit of lithium-ion battery is put forward based on mechanical tests and theoretical analysis References | Related Articles | Metrics

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Robust Optimization of Occupant Restraint SystemBased on PSO-SVR Approximation Model Zhang Haiyang, Hu Shuaishuai, Zhou Dayong, Gao Jianwu, Gu Xianguang 2020, 42 (4):  462-467.  doi: 10.19562/j.chinasae.qcgc.2020.04.007 Abstract ( 223 )   PDF (1827KB) ( 435 )   Save By comprehensively utilizing the parameter optimization technique for approximate model and robust optimization method, vehicle occupant restraint system is optimized. The parameters having significant effects on weighted injury criterion (WIC) are selected by global sensitivity analysis. The parameters of support vector regression (SVR) model and kernel function are optimized by using particle swarm optimization (PSO) algorithm, and a high accuracy PSO-SVR approximation model is established. On the basis of deterministic optimization, robust optimization based on Monte Carlo sampling is also carried out. The results show that after optimization the performances of occupant restraint system are apparently enhanced with good robustness References | Related Articles | Metrics

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Study on Mechanical Response Characteristicsof Occupant Pelvis in Vehicle Crash Wu Hequan, Hou Haibin, Hu Lin 2020, 42 (4):  468-476.  doi: 10.19562/j.chinasae.qcgc.2020.04.008 Abstract ( 242 )   PDF (3438KB) ( 548 )   Save The mechanism of occupant pelvis injury and the effects of age on its impact response are studied in this paper. Firstly the finite element model for the elder pelvis is developed and verified. Then, three pelvis models with different age characteristics (elder pelvis model, middle-aged pelvis model GHBMC and child pelvis model CHARM-10) are used to compare their differences in material properties, physiological characteristics, mechanical response and impact injury. The results show that the elder and middle-aged pelvis models have similar physiological geometry, but they are quite different from the child pelvis model. The results of side impact experiment indicate that among three pelvis models for different ages, the elder pelvis model has the largest peak impact force and deflection at maximum force, but has the smallest deflection under impact. According to the fitting of impact response data, with the rise of impact energy, the peak impact force exhibits an exponential increase while the maximum deflection shows a linear increase for all three pelvis models of different ages. Finally the results of analysis on stress nephogram indicate that the parts of pelvis prone to injury and fracture are ischio-pubic rami, iliac-sacral junction and acetabulum References | Related Articles | Metrics

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Internal Model Control During Shifting of Dual Clutch Automatic Transmission Chen Haowen, Chen Li, Liu Fengyu 2020, 42 (4):  477-483.  doi: 10.19562/j.chinasae.qcgc.2020.04.009 Abstract ( 269 )   PDF (2200KB) ( 427 )   Save To improve the smoothness of the shifting process of the dual clutch transmission, an IMC control method is proposed to improve the tracking accuracy of the speed difference of the clutches. Torque disturbance compensator is designed to reduce the effect of torque disturbance from the engine side and the load side. Meanwhile an advanced correction controller is designed according to the smoothness and differentiability of the reference speed difference. The proposed IMC structure is stable despite of model uncertainties and disturbances. The simulation and bench test results show that the proposed controller can achieve smaller tracking error and smooth shift effect under different reference input and model parameters References | Related Articles | Metrics

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Research and Development of Quality Inspection System for Inner Wall ofValve Core Holes of Vehicle Automatic Transmission Valve Body Zhu Yetian, Shen Hong, Zhang Wenjun, Lin Li, Wu Shaoteng, Ao Yunke,Wan Yu, Zhao Zhiqian, Pei Jingyu 2020, 42 (4):  484-490.  doi: 10.19562/j.chinasae.qcgc.2020.04.010 Abstract ( 392 )   PDF (3295KB) ( 395 )   Save For the automatic processing quality inspection of automobile automatic transmission valve body, a design scheme of automatic inspection system based on industrial endoscope photography is proposed. The scheme integrates several modules such as machinery, electronic control, vision and software, to realize automatic visual inspection, and prototype development and shooting test of key parts of the system are carried out. The results show that the system can effectively complete the full-view image shooting and defect feature extraction of the inner wall within the valve hole, which contributes to improve the detection accuracy, to facilitate data archiving, and finally to improve the automation level of the factory References | Related Articles | Metrics

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Modelling and Dynamic Simulation of Torque Vectoring Differential for EV Wang Junnian, Ni Jiantu, Yang Bin, Francis Assadian 2020, 42 (4):  491-497.  doi: 10.19562/j.chinasae.qcgc.2020.04.011 Abstract ( 468 )   PDF (2266KB) ( 551 )   Save A centralized electric drive-axle system having a novel differential with torque vectoring function is proposed. This centralized drive system can achieve arbitrary distribution of driving torque between the left and right wheels like the distributed drive-style, without changing the total driving torque, so as to generate a direct yaw moment which can change the yaw dynamics of the vehicle. Firstly, the structural characteristic and working principle of the torque-vectoring differential is analyzed. Secondly, the dynamics model is established by using the bond-graph theory, and its dynamic response characteristics are analyzed by simulation. Then, the torque response control system is designed to improve dynamic performance of the proposed differential. Finally, it is embedded into the vehicle model to implement joint simulation. The results show that the vehicle equipped with the proposed differential can distribute arbitrarily the driving torque between the left and right wheels, and the vehicle handling performance is effectively improved References | Related Articles | Metrics

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Inherent Characteristic Analysis of Powertrain Mounting SystemBased on Multidimensional Parallelepiped Model Lü Hui, Yang Kun, Yin Hui, Shangguan Wenbin, Yu Dejie 2020, 42 (4):  498-504.  doi: 10.19562/j.chinasae.qcgc.2020.04.012 Abstract ( 349 )   PDF (940KB) ( 375 )   Save In engineering practice, it is inevitable that parametric uncertainties exist in the powertrain mounting system (PMS) of a vehicle and there is simultaneously a certain correlation and independence between the uncertain parameters. In this paper, the multidimensional parallelepiped model (MPM) is introduced to deal with the case of the co-existence of the system parameter correlation and independence, and a method of uncertainty analysis of the inherent characteristic of the mounting system is proposed by combining the Monte Carlo method. The analysis procedure of the proposed method is presented as well. The numerical analysis results of a mounting system show that the proposed method can effectively deal with the correlation and independence of the uncertain parameters of the system. Compared with the interval methods without considering parameter correlation, the proposed method can obtain more reasonable interval responses of natural frequencies and decoupling rates. Furthermore, for the given investigated model, the stiffness correlation of the left and right mounting points has obvious influence on the system inherent characteristics, which should be paid a special attention in the process of design and research References | Related Articles | Metrics

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Multi-target Control for Heterogeneous Platoon ofBattery Electric Commercial Vehicle Wang Xuetong, Luo Yugong, Jiang Fachao, Yu Jie 2020, 42 (4):  505-512.  doi: 10.19562/j.chinasae.qcgc.2020.04.013 Abstract ( 379 )   PDF (2640KB) ( 488 )   Save Platooning research can effectively solve the problems of freight safety, energy waste and environmental pollution of commercial vehicles, but the most existing platooning researches are based on homogeneous platoon with single target tracking control, which cannot achieve good control effects in real world freight scenes. In this paper, a heterogeneous platoon composed of battery electric commercial vehicles is constructed, for which a distributed nonlinear model predictive controller is designed. According to the road environmental information and the tracking, safety, comfort and energy saving characteristics of vehicle, the controller models for leading vehicle and follower vehicles are established respectively to realize the multi-target control of heterogeneous platoon. For verifying the effectiveness of the control method proposed, a control simulation platform for a heterogeneous platoon consisting of 5 commercial vehicles with different dynamic characteristics is built, and a Trucksim/Simulink co-simulation is conducted. The results show that the control algorithm proposed can effectively achieve multi-target control of the heterogeneous platoon of commercial vehicle, with an over 5.3% reduction in energy consumption, compared with PIC constant-speed cruise control References | Related Articles | Metrics

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Weight Allocation Strategy Between Human and MachineBased on the Preview Distance to Lane Center Chen Wuwei, Wang Qidong, Ding Yukang, Zhao Linfeng, Wang Huiran, Xie Youhao 2020, 42 (4):  513-521.  doi: 10.19562/j.chinasae.qcgc.2020.04.014 Abstract ( 547 )   PDF (2358KB) ( 493 )   Save This paper proposes a human-machine weight allocation strategy for the problem of the control authority conflict between the driver and assistance system in lateral motion control of intelligent vehicle. The preview distance to lane center (PDLC) of the vehicle at the preview point is used to evaluate the lane departure risk and the preview distance to lane center is obtained by correcting the preview deviation. The weight allocation function is designed using PDLC as the independent variable, with the priority control objective of ensuring the driver's control weight and the prerequisite of certain lateral motion control accuracy. Experimental verification and data analysis of the proposed control strategy are carried out by the joint simulation platform of CarSim/Simulink and CarSim/Labview RT hardware in the loop test bench. The results show that when the weight allocation strategy is used to coordinate the control effect of the driver and assistance system, it will ensure the driver's control weight under the premise of effectively tracking the ideal lane center, reduce the workload and correct the misoperation of the driver References | Related Articles | Metrics

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Numerical Simulation and Prediction of A-Pillar and Rear-viewMirror Induced Vehicle Interior Aerodynamic Noise Tang Rongjiang, Hu Binfei, Zhang Miao, Lu Zengjun, Xiao Fei, Lai Fan 2020, 42 (4):  522-530.  doi: 10.19562/j.chinasae.qcgc.2020.04.015 Abstract ( 799 )   PDF (3787KB) ( 4013 )   Save Aiming at the issue of front window and interior aerodynamic noise caused by rear-view mirror, the numerical simulation of exterior rear-view mirror region and prediction of interior noise in a commercial vehicle are studied by using computational fluid dynamics (CFD) method. The SST(Menter)k-ω model in RANS model is used for steady-state analysis, and the detached eddy simulation based on the SST(Menter)k-ω model is used for transient analysis. By analyzing the nephograms of steady static pressure and transient dynamic pressure, velocity and vorticity, the mechanism of turbulent pressure fluctuation of side window caused by A-pillar and rear-view mirror is revealed, meanwhile the transient flow field is solved to obtain the surface turbulent pressure fluctuation load on two side windows. Acoustic FEM method is adopted to calculate the propagation of aerodynamic noise with the turbulent pressure fluctuation on window surface as boundary condition. Based on the distribution law of sound pressure level nephogram of interior acoustic space at different frequencies, it is indicated that the interior aerodynamic noise is mainly concentrated in the middle and low frequency ranges and the maximum distribution region of sound pressure level, and the sound pressure level curve at driver's left ear exhibits the variation law of the sound pressure level in the frequency range of 20-2 500 Hz. Finally, a real vehicle coasting road test is conducted, verifying the conclusion that the aerodynamic noise is more apparent at the speed range of 80-110 km/h. The adoption of CFD technique combined with acoustic FEM can relatively accurately predict the sound pressure level of interior aerodynamic noise at the frequency range of 100-2 500 Hz, providing technical schemes of simulation and test for optimizing rear-view mirror and reducing cabin aerodynamic noise References | Related Articles | Metrics

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Virtual Transfer Path Analysis of Vehicle InteriorNoise and Vibration in Low Frequency Tang Zhonghua, Zhang Zhifei, Chen Zhao, Pu Hongjie, Li Yun, Xu Zhongming 2020, 42 (4):  531-536.  doi: 10.19562/j.chinasae.qcgc.2020.04.016 Abstract ( 555 )   PDF (1887KB) ( 566 )   Save Transfer path analysis (TPA) is an accurate and effective method to diagnose vehicle vibration and noise of automobile. The test TPA is time-consuming and labor-intensive and requires a prototype car, in order to diagnose the vehicle vibration and noise problems in the initial stage of vehicle development, the virtual TPA method is studied. Firstly, a vehicle structure-acoustic coupling finite element model with chassis is developed and the frequency response method is used to predict the acoustic vibration response in the vehicle. It is found that there exist peak values at 38 Hz of the sound pressure of the driver's right ear and at 59 Hz of the vibration of the guide rail of the driver's seat. The virtual TPA model based on the finite element model is developed. The results of acoustic vibration reconstructed by the model are consistent with that of frequency response method, which verifies the correctness of the model. The two peak values are diagnosed with virtual TPA method and the dominant paths are optimized according to the analysis results. The optimization results show that the sound pressure of driver's right ear at 38 Hz is reduced by 2 dB, and the seat vibration at 59 Hz is improved obviously References | Related Articles | Metrics

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Robust Optimization Design for Free Damping Layer of Vehicle Body Panel Su Shijian, Xu Yuanli, Gong Jian, Xia Hongbing, Hu Haiou, Huo Junyan 2020, 42 (4):  537-544.  doi: 10.19562/j.chinasae.qcgc.2020.04.017 Abstract ( 232 )   PDF (2412KB) ( 489 )   Save In the optimization design of the free damping layer of the vehicle body panel, a robust optimization design method considering uncertain fluctuation of damping material parameters is proposed. Firstly, damping materials are full-coated on the body areas such as firewall, floor and ceiling. Secondly,topological optimization of the damping layer layout is carried out taking the equivalent radiated power (ERP) as the optimization objective and the optimization effect is verified. Finally, the six sigma robust optimization design of the damping layer is carried out by taking the thickness of the damping layer as random design variable, the loss factor and elastic modulus as random variables, and the minimum mass as optimization objective, and combining the radial basis function (RBF) approximation model, Monte Carlo simulation (MCS) and sequential quadratic programming (SQP). The results show that the total mass of the free damping layer is reduced by 50.45% after optimization, and the noise performance of the body structure reaches the six sigma quality level, which achieves the goal of robust optimization of the damping layer under the requirement of lightweight body References | Related Articles | Metrics

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Robust Optimization for Hybrid (Bolted/Bonded) Connection ofMagnesium-Aluminum Alloy Assembled Wheel Wang Dengfeng, Xu Wenchao 2020, 42 (4):  545-551.  doi: 10.19562/j.chinasae.qcgc.2020.04.018 Abstract ( 196 )   PDF (2556KB) ( 392 )   Save This paper proposes a multi-objective deterministic and robust optimization design method for hybrid bolted/bonded connection of magnesium-aluminum alloy assembled wheel. Firstly, the finite element model of the magnesium-aluminum alloy assembled wheel with bolt connection is established and the bending fatigue life simulation is conducted, and then the validity of the simulation model is verified by comparing the fatigue test results. Subsequently, the elasto-plastic constitutive model of structural adhesives is established, and the stress-strain curves and shear strengths are obtained through experiments. Finally, the thickness and type of adhesive layer, pretension force of bolt, hole diameter of bolt are selected as the design variables and the parametric simulation model is established for wheel hybrid bolted/bonded connection. The maximum tensile/shear stress of the structural adhesive and fatigue life of the connecting bolts are identified as the optimization target, the Elitist non-dominated sorting genetic algorithm (NSGA-II) and micro-archive genetic algorithm (AMGA) are respectively adopted to establish the multi-objective optimization and 6σ robust optimization design of the wheel with hybrid bolted/bonded connection on the ISIGHT optimization platform. The reliability of the wheel connection is further improved after the robust optimization References | Related Articles | Metrics

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Study on Construction of Typical Closing Driving Force of Vehicle Sliding Door Gao Yunkai, Yuan Ze, Duan Yuexing 2020, 42 (4):  552-559.  doi: 10.19562/j.chinasae.qcgc.2020.04.019 Abstract ( 217 )   PDF (1285KB) ( 350 )   Save To provide reliable input data for the study on the dynamic characteristics of guidance system of sliding door, the typical closing driving force is constructed based on the test data of sliding door closing force of a vehicle model. Firstly, some characteristic parameters are extracted from the massive measured closing force curves under three closing conditions and PauTa criterion is used to reject outlier data. On this basis, Markov chain is applied to the construction of the typical closing driving force of sliding door with their curves fitted into STEP function to realize the loading of driving force in engineering. Finally, in order to verify the effectiveness of the method used, characteristic parameter data before and after fitting are compared with the average value of tested characteristic parameter data. The results indicate that their relative errors are less than 10% for three closing conditions, illustrating the effectiveness and feasibility of the method of closing driving force construction References | Related Articles | Metrics

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Optimization Design Method of Multi-material Car BodyStructure Based on Modified Graphic Decomposition Zhao Yonghong, Li Yongcheng, Chen Dong, Hou Wenbin 2020, 42 (4):  560-566.  doi: 10.19562/j.chinasae.qcgc.2020.04.020 Abstract ( 384 )   PDF (1543KB) ( 541 )   Save Aiming at the lightweight design of car body structure in concept design phase, a hierarchy iteration optimization scheme is proposed which can realize multi-material structure design of car body. In the optimization scheme, the design variables include the topology connection beside panel thickness and material as usual, for meeting the requirements of ‘putting the right material on the right position’. In the first layer of hierarchy iteration optimization, with topology connection as design variable, graphic decomposition and NSGA-II are adopted to conduct multi-objective optimization on the topology structure in car body assembling, maximizing the bending and torsional stiffness and the first-order natural frequency of car body. In the second layer, multi-objective optimization is performed on panel thickness and material, minimizing the mass of car body and material cost. Finally, fuzzy set-based scoring formulae are used to select the comprehensively optimum solution, achieving the light-weight design of car body structure with cost consideration References | Related Articles | Metrics