• Structural Engineering and Mechanics
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• v.68 no.5
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• pp.633-638
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• 2018

One of the important problems in the vehicle design is vehicle handling and stability. Effective parameters which should be considered in the vehicle handling and stability are roll angle, camber angle and scrub radius. In this paper, a planar vehicle model is considered that two right and left suspensions are double wishbone suspension system. For a better analysis of the suspension geometry, a kinestatic model of vehicle is considered which instantaneous kinematic and statics relations are analyzed simultaneously. In this model, suspension geometry is considered completely. In order to optimum design of double wishbones suspension system, a multi-objective genetic algorithm is applied. Three important parameters of suspension including roll angle, camber angle and scrub radius are taken into account as objective functions. Coordinates of suspension hard points are design variables of optimization which optimum values of them, corresponding to each optimum point, are obtained in the optimization process. Pareto solutions for three objective functions are derived. There are important optimum points in these Pareto solutions which each point represents an optimum status in the model. In other words, corresponding to any optimal point, a specific geometric position is determined for the suspension hard points. Each of the obtained points in the Pareto optimization can be selected for a special design purpose by designer to create an optimum condition in the vehicle handling and stability.

• Structural Engineering and Mechanics
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• v.55 no.6
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• pp.1203-1221
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• 2015

By taking a cable-stayed-suspension hybrid bridge with main span of 1400 m as example, seismic response of the bridge under the horizontal and vertical seismic excitations is investigated numerically by response spectrum analysis and time history analysis, its seismic performance is discussed and compared to the cable-stayed bridge and suspension bridge with the same main span, and considering the aspect of seismic performance, the feasibility of using cable-stayed-suspension hybrid bridge in super long-span bridges is discussed. Under the horizontal seismic action, the effects of structural design parameters including the cable sag to span ratio, the suspension to span ratio, the side span length, the subsidiary piers in side spans, the girder supporting system and the deck form etc on the seismic performance of the bridge are investigated by response spectrum analysis, and the favorable values of these design parameters are proposed.

• Journal of KSNVE
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• v.5 no.1
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• pp.67-73
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• 1995

In earth moving construction equipment used for rough and dangerous works, seat suspension system is the only means for reducing the vibration transmitted to the operator. Thus ISO(International Organization for Standardization) 7096 suggests a recommendation for the vibration characteristics of the seat suspension system in order to protect the human beings from excessive vibrationl. In this research, a new mechanical type seat suspension system is designed and a mathematical model, effective design parameters of the seat suspension system are determined and concept design strategy is presented.

• Transactions of the Korean Society of Automotive Engineers
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• v.4 no.6
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• pp.121-132
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• 1996

As a new suspension is being designed, the designer should consider that the vehicle has a good ride and handling performance. It is not easy for a yound desigineer to decide the design parameters. In this study, the design process of a suspension system is described. the method of optimized design to achieve the target of vehicle performance from the initial layout to detailed design stage is also described. As a result, the effects of design parameters in the vehicle dynamic performance are mentioned by the synthesized program

• Transactions of the Korean Society of Automotive Engineers
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• v.4 no.1
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• pp.16-27
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• 1996

Using computer in design is a trend in recent years. A good suspension model is depend on the carefully prepared data like joint connection points or spring stiffness, etc. Once a good computer model is obtained, a parametric study for spciffic suspension design factor, like a toe angle, can be done to obtain sensitivity information. Using this information, several important design parameters for a specific design factor can be identified. Once a design of experiments is done using computer models, the results can be used to approximate a function which can best represent the experimentation. An optimum solution of this function can be used to find an optimum design of a suspension system for a specific suspension design factor. Same method is again applied to other design factors iteratively until a good suspension system design is obtained.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.33 no.9
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• pp.903-912
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• 2009

This study is focused on simulation-based dimensional tolerance optimization process (DTOP) to minimize vehicle pulls by reduction of dimensional variation in front suspension system. In previous studies, the effect of tires and wheel alignment sensitivity have mainly been investigated to eliminate vehicle pulls in nominal design condition without allocating optimal tolerance level for selected components, among various factors regarding vehicle pulls such as vehicle design parameters, vehicle weight balance, tires, and environmental factors. Unfortunately, there are wide variations in the real vehicle, and these have impacted actual vehicle pulls, especially wheel alignment effects from suspension geometry variation has not been considered in the previous studies. In the tolerance design of suspension, tolerance variables with the uncertainty such as parts dimensional variation, assembly process, datum position and direction, and assembly tool tolerance has a great influence on the variation of the suspension dimensional performances. This study introduces total vehicle pull prediction model in considering major key factors for vehicle pull sensitivity. The Monte Carlo-based tolerance analysis model using Taguchi robust method is developed to optimize dimensional tolerance parameters, satisfying on the target variation level.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.18 no.4
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• pp.410-416
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• 2009

In recent years, the rollover accident of large class of vehicles has become important safety issue. Even though the rollover form a small percentage of all traffic accidents, they have a fatal effect upon the driver and passenger. Among the traffic accidents occurred in driving, the rollover is the major cause of traffic fatalities. Therefore, it is required to develop the analytical and experimental techniques for predicting rollover propensity of vehicles and also to improve the vehicle suspension design in the viewpoint of rollover resistance. In this study, the parameter sensitivities for the roll angle of SUV suspension are analyzed, and then the determined design parameters are optimized by using the regression model function of the response surface methods. The analysis results show that the roll angle of the optimized vehicle is decreased as compared with the initial vehicle and also the rollover possibility is decreased when the roll rate of the front suspension is larger than the roll rate of the rear suspension.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.1
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• pp.25-30
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• 2006

This study is about an optimum design to improve the kinematic and compliance characteristics of a torsion-beam suspension system. The kinematic and compliance characteristics of an initial design of the suspension was obtained through a roll-mode analysis. The objective function was set to minimize within design constraints. The coordinates of the connecting point between the torsion-beam and the trailing arm were treated as design parameters. Since the torsion-beam suspension has large nonlinear effects due to kinematic and elastic motion, Genetic Algorithms were employed for the optimal design. The optimized results were verified through a double-lane change simulation using the full vehicle model.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11b
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• pp.771-776
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• 2002

Optimal shape of the NFR suspension is studied and developed to improve the dynamic performance and reduce the vibration of the suspension system including a optical head slider. Since accurate position control and stability of the slider motion are highly required in NFR due to the narrower track width and the heavier slider than HDD slider with the low flying height, the dynamic characteristics of the suspension are very important to the mechanical performance of the system. The first natural frequencies in flexural and lateral motion of the suspension are critical factors affecting the dynamics and stability of the flying head, so that the dynamic parameters should be designed properly to avoid an excessive vibration or a crash of the slider on the disk. This paper optimizes the shape of the suspension based on homogenization method in NASTRAN and develops a new suspension shape for NFR system. The suspension is tested on experiment to verify the improvement of the dynamic characteristics.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10a
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• pp.334-337
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• 1996

This is a paper intended for initial stage of vehicle modeling and design. The needs to determine a variety of vehicle suspension parameters required for initial design has been difficult and time-consuming task. In order to facilitate a concise and efficient presentation of initial vehicle design procedure, this paper uses a mathematical model and physical geometry. Vehicle model consists of dimensions, inertias and mechanical constants. These vehicle model parameters divided into several categories : basic parameters, coefficients and constants, design specification, spring and damper, bush stiffness, stabilizer bar, suspension geometry, tire, and vehicle weights of various design condition. This paper uses a vehicle design fundamental (VDF) program running under Windows 95 graphical interface. The features of VDF will be briefly outlined in this paper.