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Gao Y.,Tongji University | Xu C.,Tongji University | Fang J.,Tongji University | Liu W.,Geely Automobile Research Institute
Qiche Gongcheng/Automotive Engineering | Year: 2013

Taking the closure panels of a passenger car as an example, the contents, specifications and procedures of stiffness test for automotive closures are presented in this paper. In addition, the finite element analysis software Abaqus is used to analyze the relevant factors influencing the results of stiffness test, providing references for the structure design of automotive closures.

Li F.F.,Hong Kong Polytechnic University | Li F.F.,Tongji University | Fu M.W.,Hong Kong Polytechnic University | Lin J.P.,Tongji University | Wang X.N.,Geely Automobile Research Institute
International Journal of Advanced Manufacturing Technology | Year: 2014

To reveal the effects of forming temperature and blank thickness on the formability of boron steel 22MnB5, which is represented by forming limit diagram, the hot forming limit experiments and B-pillar hot stamping simulations are conducted. Combined with air cooling test, the forming limit diagrams of boron steels with different blank thicknesses of 1.8, 1.6, and 1.4 mm and forming temperatures of 800, 700, and 600 C are established. The relationships between the formability and the crystal structure of steel, the forming limit diagram, and the effect of blank thickness and forming temperature on the formability of boron steel are extensively investigated. A model for prediction of hot forming limit of 22MnB5 steel before the occurrence of phase transformation induced by cooling based on Oh's ductile fracture criterion and Logan-Hosford yield criterion is derived and verified by experiments. The research thus provides an in-depth understanding of the formability of 22MnB5 steel for its process determination and process parameter configuration in industries. © 2013 Springer-Verlag London.

Ma F.,Geely Automobile Research Institute | Guo D.,Geely Automobile Research Institute
Lecture Notes in Electrical Engineering | Year: 2013

Research Objective The sound quality of automobiles has drawn much attention, and sound quality of door slamming will impact psychological tendency of customers during vehicle purchase. Therefore, this chapter provides test and evaluation method for sound quality of door slamming and its improvement measures. Methodology For test method, the proper position of door slamming force acting location, velocity range of door slamming, consistency of slamming force each time and layout of microphone are the factors which are taken into account. For evaluation method, factors such as pulse convergence time, sharpness, loudness, duration of low-frequency residual noise and high-frequency noise are considered. Thirdly, for optimization for door slamming, subjective evaluation, objective analysis and exclusion method are applied. Results Through optimization of vehicle sealing, design of door latches, layout of weather strips, return spring of door handle, and contact location between handle and base, the door slamming sound quality can be improved. Limitations of this study CAE simulation analysis should be carried out at all stage. What does the chapter offer that is new in the field including in comparison to other work by the authors: A series of measures to improve the door slamming sound quality are introduced in detail. Conclusion Evaluation method for the sound quality is presented, and practical improvement measures are proposed. © 2013 Springer-Verlag.

Tong D.,Geely Automobile Research Institute | Hao Z.,Zhejiang University
Qiche Gongcheng/Automotive Engineering | Year: 2015

In order to improve the vibration isolation performance of powertrain mounting system, a deterministic optimization on mounting parameters (the stiffness, position and angle of mounting) is conducted by using adaptive simulated annealing algorithm with maximizing the energy decoupling rates of mounting system as objective, the natural frequencies of system vibration as constraints. Considering the variation of mount stiffness due to manufacturing error, and for enhancing the reliability and robustness of design, Monte Carlo simulation (MCS) technique is used to analyze the reliability of new design scheme, and design for six sigma (DFSS) technique is adopted to perform further optimization on mounting system. The results show that compared with deterministic optimization, with optimization by using MCS and DFSS techniques, the nominal energy decoupling rates and natural frequencies of powertrain mounting system have not much change, but the reliability and robustness of system are greatly improved. ©, 2015, SAE-China. All right reserved.

Yao Z.,Geely Automobile Research Institute | Ma M.,Geely Automobile Research Institute | Liu Q.,Geely Automobile Research Institute | Zhao F.,Geely Automobile Research Institute
Procedia Engineering | Year: 2011

Effect of doping with trace zirconium on microstructure, electrical resistivity and strength of the iron-fiber reinforced Cu-Fe wires were investigated. The spherical ZrO 2 particles were homogeneously distributed in Fe-fiber and Cumatrix of Cu-11.3Fe-0.2Zr wire. The ultimate tensile strength and the conductivity of Cu-11.3Fe-0.2Zr wire cold drawn to the drawing strain ? = 7.57 with intermediate annealing were observed to be 824 MPa and 61.4% IACS, however, those of Cu-11.3Fe were 752 MPa and 64.6% IACS respectively. The thermal stability of Cu-matrix wire was improved by doping zirconium. Compared with Cu-11.3Fe wire, the strength of Cu-11.3Fe-0.2Zr wire does not drop more rapidly during aging treatment above 300 °C. © 2010 Published by Elsevier Ltd.

Li Y.,Geely Automobile Research Institute
SAE Technical Papers | Year: 2013

An investigation was performed on steering tie rod for cracking with strength and buckling analysis theory, which showed a low risk of failure. In order to solve this problem, a necking down method was used to optimize the length and location by Arc Length Algorithm, which was proved by pressing and impact test. It is shown that simulation results are in consistency with tests, necking down can alleviate cracking and improve quality efficiently on the premise of mere decrease in pressure resistance. Copyright © 2013 SAE International.

Ma F.,Geely Automobile Research Institute | Qu Z.,Geely Automobile Research Institute
Lecture Notes in Electrical Engineering | Year: 2013

The recently proposed online mean-value thermodynamic combustion model suffers from its error-prone CA50 prediction. In an effort to improve the accuracy of CA50 prediction in the case of ignition retard, this chapter demonstrates the convergence of normalized IMEPH-CA50 predictions towards a unanimous characteristic curve indiscriminately for various gasoline engine selections, speeds and loads. For the first time, this chapter reveals the physical principle of a characteristic curve via an ideal-heat-release model and thereby formulates a validity region of the IMEPH-CA50 predictions. The predicted values outside of the region will then be corrected by a surrogate of the characteristic curve. In this way, ECUs successfully identify invalid CA50 predictions online and modulate them towards the actual values. Large-scale experiments have shown the developed method improves the accuracy in CA50 prediction, while preserving the high accuracy of IMEPH prediction. © 2013 Springer-Verlag Berlin Heidelberg.

Qu Z.,Geely Automobile Research Institute | Ma M.,Geely Automobile Research Institute | Zhao F.,Geely Automobile Research Institute
SAE Technical Papers | Year: 2012

Intake volumetric efficiency (VE) of a spark-ignition engine varies with valve timings, engine speeds, and manifold air loads. The existing approaches to reveal the underlying effects of these VE factors on instant valve flows remain complicated and expensive. In an effort to develop an applicable approach to analyze the detail valve flows, a naturally aspirated production engine with dual independent VVT was dynamometer-tested with fast in-cylinder pressure measurements and slow manifold pressure measurements. Both intake and exhaust valve flow was then reproduced using a new model, DQS model, in crank-angle resolution (CAR). One new flow mechanism, the flow wave subsidence, has been revealed to be one of the major drives of VE changes. We propose a dynamic quasi-steady (DQS) flow model to reproduce the valve flow profile from the measured pressure data. The DQS model features two manifold dynamics and a delay in the use of in-cylinder pressure measurements. The delay represents the effect of duct gas inertia on quasi-steady flow formation. In order to determine the delay amount as well as the model discharge coefficients, we construct an effective calibration method which matches the calculated valve flow profile with the estimated net cylinder flow. The DQS model results were validated with measured residual gas amount and overall charge amount in a large number of test runs with vastly different valve timings, engine speeds and loads. Copyright © 2012 SAE International.

Qu Z.,Geely Automobile Research Institute | Ma M.,Geely Automobile Research Institute | Zhao F.,Geely Automobile Research Institute
SAE Technical Papers | Year: 2012

Online combustion efficiency optimization in a variable-valve-timing (VVT) gasoline engine requires the real-time knowledge of in-cylinder pressure and its various derivatives. The in-cylinder pressure measurements, however, are still inapplicable to current light duty vehicles due to the high cost of fast pressure sensors. In this paper, an effective combustion model is developed to provide online prediction of crank-angle resolved (CAR) in-cylinder pressure evolution given five representative initial states at intake valve closing (IVC). The prediction of the combustion pressure is made by incorporating mean-value mass/energy flow models with the first law thermodynamics. To achieve real-time calculation for end-use engines, this paper improves the validity region of the existing mass/energy flow models while preserving their simplicity. In particular, the model performances of chemical heat release, crevice flow and heat transfer are closely examined for a wide operation range and then renovated accordingly. This paper also proposes a new calibration scheme which uses in-cylinder pressure measurements only to parameterize all model coefficients as functions of the initial states. The overall calibrated model is implemented online using high-power chip and validated for 3787 test runs with a wide range of engine speeds, loads, residual gas fraction (RGF), air-fuel ratios and ignition timings. Copyright © 2012 SAE International.

Chu H.,Jilin University | Chen Y.,Geely Automobile Research Institute | Guo L.,Geely Automobile Research Institute | Gao B.,Jilin University | Chen H.,Jilin University
SAE Technical Papers | Year: 2015

In order to improve the drivability and reduce the clutch friction loss, low-cost slope sensor is used in hill-start control of AMT vehicles. After the power spectrum analysis of the original signal and the design of the digital filter, the angle of the slope is obtained with short enough delay and small enough noise. By using this slope angle information, slope resistance force can be calculated online so that the vehicle can be prevented from sliding backward and optimal launch control can be realized. The digital filter of slope angle signal and the optimal controller of dry clutch engagement are embedded in the TCU (Transmission Control Unit) of a micro-car Geely Panda. Real-vehicle experiments are carried out with optimal clutch controller, which shows that the hill-start with low-cost slope sensor and optimal clutch controller can provide successful vehicle launch with little driveline shock. In addition, it can also avoid backward sliding and engine over-speed effectively. Furthermore, hill-start with low-cost slope sensor and optimal clutch controller can reduce clutch wear, extend the life of dry clutch and improve the drivability. Copyright © 2015 SAE International.

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