• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1998.04a
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• pp.51-56
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• 1998

This paper presents modal contribution method to reduce vehicle vibration. Normal mode analysis is performed to obtain modal vector matrix. The proposed method uses this modal vector matrix to evaluate forced response of an active mode to the applied engine forces and the rotating force due to wheel unbalance mass. Comparing the responses, of the specific active mode with one another, it can be easily done to determine most contributed mode in the interesting frequency band. Then we can find dominant bushes by the strain energy distribution of the mode. Vibration response is decrease with modification of those bushes.

• The Journal of the Acoustical Society of Korea
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• v.16 no.1
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• pp.54-59
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• 1997

The vehicle vibrations result from the exciting forces which are caused by air resistance, engine firing, tire mass unbalance and tire uniformity. Especially, the shake and shimmy phenomena in the steering system are closely related to the vehicle vibration, the tire unbalance, and the tire uniformity. This study presents the shimmy phenomena due to the tire mass unbalance and the tire uniformity in order to investigate their effects.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.17 no.5
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• pp.10-22
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• 2008

In an automotive body structure, a design configuration that fulfills structural requirements such as deflection, stiffness and strength is necessary for structural design and is composed of various components. The integrated design is used to obtain a minimum weight structure with optimal or feasible performance based on conflicting constraints and boundaries. The mechanical design must begin with the definition of one or more concepts for structure and specification requirements in a given application environment. Structural optimization is then introduced as an integral part of the product design and used to yield a superior design to the conventional linear one. Although finite element analysis has been firmly established and extensively used in the past, geometric and material nonlinear analyses have also received considerable attention over the past decades. Also, nonlinear analysis may be useful in the area of structural designs where instability phenomena can include critical design criteria such as plastic strain and residual deformation. This proposed approach can be used for complicated structural analysis for an integrated design process with the nonlinear feasible local flexibilities between system and subsystems.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.17 no.4
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• pp.67-74
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• 2008

The important dynamic specifications in the aluminum automobile body design are the vibrations and crashworthiness in the views of ride comforts and safety. Thus, considerable effort has been invested into improving the performance of mechanical structures comprised of the interactive multiple sub-structures. Most mechanical structures are complex and are essentially multi-criteria optimization problems with objective functions retained as constraints. Each weight factor can be defined according to the effects and priorities among objective functions, and a feasible Pareto-optimal solution exists for the criteria-defined constraints. In this paper, a multi-criteria design based on the Pareto-optimal sensitivity is applied to the vibration qualities and crushing characteristics of front structure in the automobile body design. The vibration qualities include the idle, wheel unbalance and road shake. The crushing characteristic of front structure is the axial maximum peak load.