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In regard to the evaluation of the performance of a hybrid electric vehicle (HEV), there are as many simulation methods as there are developers or researchers. They adopt different operational algorithms and they use diverse techniques to realize their logic. However, the relation among the various simulation methods has not been clearly defined. Thus, it is not easy to choose a method that would bring the best consequences in the most efficient way. Here, we present three types of backward-looking simulation algorithms for evaluating the fuel efficiency of a power-split HEV. Then the results and cost-effectiveness of each algorithm are analyzed using various component ratings over a representative driving mode. Based on the comparative analysis, the algorithm that uses equivalent fuel consumption is shown to be highly cost-effective. Also, an inductive or empirical base is set up with the results for a component sizing methodology using the recommended simulation.

In this paper, we investigate a method to calculate the dynamic instability of a disc brake system and propose a criterion of design modification. To estimate dynamic instability, complex eigenvalue analysis is performed for a brake system and the contribution factor of each component to an unstable complex mode is calculated using complex MAC(Modal Assurance Criteria). From the contribution factors, the most influential component is determined so as to decouple the complex mode, and its geometry is modified in view of the strain energy distribution. Evaluation through noise dynamometer tests verifies the reduction of squeal noises, and this is in accordance with the results of complex eigenvalue analysis.

This paper describes a simulation procedure to calculate a torque converter performance. The study focuses the validity of a solution and the handiness of the procedure. A comparison of the numerical solution and the experimental solution proves the model validity. Moreover, handiness is achieved by using commercial code with automatic unstructured mesh generating techniques. With suggested procedure, a complete analysis is carried out relatively fast. And an steady state interaction can be analyzed between three moving elements.

This paper presents the vibration control of a thin plate by multiple piezoelectric actuators and sensors which are co-located. To use piezoelectric materials efficiently, the Linear Quadratic Gaussian (LQG) controller is designed on the basis of a Multi-Input Multi-Output system so that each sensor monitors all the modes to be controlled and each actuator excites all the modes to be controlled. The robust LQG controller is then applied for attenuating vibration of a plate that is clamped along its edges and disturbed by a band-limited pseudo-random noise. This controller uses two sensor signal filters in order to control the first three natural modes of the plates. The results of the experiment show that the vibration of controlled modes are attenuated by 10 to 20 dB without destabilizing the other modes.

Compliance elements such as bushings of a suspension system play a crucial role in determining the ride and handling characteristics of the vehicle. In this research, a general procedure for the optimum design of compliance elements to meet various design targets is proposed. Based on the assumption that the displacements of elastokinematic behavior of a suspension system under external forces are very small, linearized elastokinematic equations in terms of infinitesimal displacements and joint reaction forces are derived. Directly differentiating the linear elastokinematic equations with respect to design variables associated with bushing stiffness, sensitivity equations are obtained. The design process for determining the bushing stiffness using sensitivity analysis and optimization technique is demonstrated.

This paper discusses the flexible foundation effects on dynamic responses of engine-mount systems using computer simulation techniques. Equations of motion for the engine-mount systems including flexible foundations are derived. The dynamic flexibility of the foundation is represented by modal information from finite element analysis or experimental modal analysis. Solving the derived equations, natural frequencies and forced vibration responses of an engine-mount system can be simulated accurately. It is shown that the flexibility of the supporting structure may have a significant effect on the idle shake vibration and mounting forces transmitted from the engine to the structure. The computational method developed is applied to an example engine-mount system and the results are compared to those of an associated experiment.

Transient characteristics during gear ratio change including the disturbance of output torque have been important issues in the study of passenger car automatic transmission. In this paper, to investigate the transient characteristics during gear ratio change, a detailed dynamic model of the power transmission system of a passenger car focused on the automatic transmission was proposed and the governing dynamic equations were derived and solved. The results of simulation showed good agreements with the experimental data. It was proved that the suggested dynamic model is very useful to analyze the phenomena occurred during the speed ratio change.

The purpose of this study is to develop a computer simulation program for analyzing load transmission and vibration, characteristics of a helical gear system in the design stage. In this analyse, the transmission error, load distribution, root stress, contact area, and vibration characteritics are investigated. That is, the influence function of deflection is obtained by finite element analysis and the influence function of approach and gear tooth error are considered. Load distribution, transmission error, and contact area are calculated by solving load-deflection equation which includes these influence functions and tooth error, and the influence function of the bending moment is obtained by finite element analysis. The root stress is calculated by the load distribution and the influence function of the bending moment. Also, mass/damping/non-linear spring model for the gears is used and the vibration levels due to tooth error are calculated.

This study establishes the scheme on the noise reduction of the interior cavity of a passenger car using the mode coupling coefficient between the structural vibration modes and the acoustic modes. A dominant noise level is identified on the running test. To reduce its level, the mode coupling analysis is carried out using pre-determined acoustic modes and structural modes. The structural modes is obtaind from modal testing for the passenger car. The acoustic modes of the interior cavity is calculated by finite element analysis. The noise level is reduced efficiently by a structural modification of the boundary panels which strongly contribute to the Interior noise. These procedures are carried out by using an user friendly computer program (ACSTAP) which is developed in this study.

This paper presents the theory and hardware to simulate non-loglinear spectra (the typical field case), including a unique method of eliminating low amplitude reversals so that any service load history of high cycle fatigue can be simulated in a laboratory fatigue test. The feasibility of the proposed quasi-stationary random process to simulate the three standard SAE load histories on a statistical basis is demonstrated on both the theoretical and experimental basis.