• Transactions of the Korean Society of Automotive Engineers
• /
• v.11 no.1
• /
• pp.121-127
• /
• 2003

The stiffness of a bushing in a suspension is extremely important for the overall performance of the suspension system. A new measurement system including the flexible jig was developed to measure the multi-directional stiffness of bushings. To overcome the disadvantage of building each individual jig for each type and size of a bushing, we designed the flexible jig which can accommodate numerous bushings of similar shapes and sizes. Upon using the novel design of the flexible jig in the industry, we could successfully measure the torsional and conical stiffness of many bushings and apply the data for the prediction and evaluation of the performance of a suspension system, which would assist designing the optimal suspension system.

• Elastomers and Composites
• /
• v.39 no.3
• /
• pp.228-233
• /
• 2004

A bushing is a device used in automotive suspension systems to reduce the load transmitted from the wheel to the frame of the vehicle. A bushing is a hollow cylinder, which is bonded to a solid steel shaft at its inner surface and a steel sleeve at its outer surface. The relation between the force applied to the shaft and the relative deformation of a bushing is nonlinear and exhibits features of viscoelasticity. Since a force-displacement relation for bushings is important for multibody dynamics numerical simulations, the relation is expressed in terms of a force relaxation function and a method of determination by experiments on bushings has been developed. For the nonlinear viscoelastic axial response, Pipkin-Rogers model, the direct relation of force and displacement, has been derived from experiment. It is shown that the predictions by the proposed force-displacement relation are in very good agreement with the experimental results.

• Elastomers and Composites
• /
• v.38 no.4
• /
• pp.334-341
• /
• 2003

A bushing is a device used in automotive suspension systems to reduce the load transmitted from the wheel to the frame of the vehicle. A bushing is a hollow cylinder, which is bonded to a solid steel shaft at its inner surface and a steel sleeve at its outer surface. The relation between the force applied to the shaft and the relative deformation of a bushing is nonlinear and exhibits features of viscoelasticity. A force-displacement relation for bushings is important for multibody dynamics numerical simulations. For the nonlinear viscoelastic axial response, Pipkin-Rogers model, the direct relation of force and displacement, has been derived from Lianis model and the sinusoidal input was used fer Pipkin-Rogers model, and the affection of displacement with frequency change was studied with Pipkin-Rogers model.

• Elastomers and Composites
• /
• v.43 no.1
• /
• pp.25-30
• /
• 2008

A bushing is a device used in automotive suspension systems to reduce the load transmitted from the wheel to the frame of the vehicle. A bushing is a hollow cylinder, which is bonded to a solid steel shaft at its inner surface and a steel sleeve at its outer surface. The relation between the force and moment applied to the shaft and the relative deformation and rotational angle of a bushing exhibits features of viscoelasticity. Since a moment-rotational angle relation for a bushing is important for multibody dynamics numerical simulations, the simple relation between the moment and rotational angle has been derived from experiment. It is shown that the predictions by the proposed moment-rotational angle relation are in very good agreement with the experimental results.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.9 no.1
• /
• pp.163-170
• /
• 2001

In this paper, a massless link model transmitting external forces is developed to achieve the numerical efficiency in simulation of vehicle suspension systems. Forces acting on links are resolved and transmitted to attached points with a quasi-static assumption. Also, a theoretical derivation and computer implementation of a massless link with bushing elements are proposed. In the massless link with bushing elements, one end is connected to the adjacent body with bushings and the other end is connected with a spherical joint. The deformation of a massless link with bushing elements is theoretically determined by minimizing the potential energy function with quasi-static equilibrium assumption at each time step. Several simulations with a full vehicle model are carried out to compare the efficiency of the developed massless link component. From the results, it is concluded that the proposed approach can reduce the computational time considerably.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.6 no.6
• /
• pp.31-39
• /
• 1998

The role of bushing elements linked between suspension parts is to enhance ride quality and handling stability by the spring and damping effect from the elastic deformation. In this paper, a theoretical derivation and computer implementation off a bushing element are proposed. Three different vehicle models are generated to test the developed bushing module. The developed bushing module is implemented as a bushing module in the vehicle dynamic analysis program AUTODYN7.

• Elastomers and Composites
• /
• v.37 no.3
• /
• pp.151-158
• /
• 2002

An elastomeric bushing which has been considered in this research is a device used in automotive suspension systems to reduce the forte transmitted iron the wheel to the frame of the vehicle. A bushing is modeled at a hollow cylinder which is bonded to a solid metal shaft at its inner surface and a metal sleeve at its outer surface. Lianis constitutive equation for a nonlinear viscoelastic incompressible material is used to model the elastomeric material of the bushing. It is used to derive a force-displacement relation for axial response of the bushing. The displacement dependent force relaxation function for the bushing is obtained from the ramp displacement control tests with an extrapolation method. This is compared with the exact result obtained from the step displacement control test and the results are in very good agreement.

• Elastomers and Composites
• /
• v.39 no.2
• /
• pp.121-130
• /
• 2004

A rubber bushing connects the components of the vehicle each other and reduce the vibration transmitted to the chassis frame. A rubber bushing has the nonlinear characteristics for both the amplitude and the frequency and represents the hysteretic responses under the periodic excitation. In this paper, one-axis durability test is performed to describe the mechanical behavior of typical vehicle elastomeric components. The results of the tests are used to develop m empirical bushing model with an artificial neural network. The back propagation algerian is used to obtain the weighting factor of the neural network. A numerical example is carried out to verify the developed bushing model and the vehicle simulation is performed to show the fidelity of proposed model.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1994.10a
• /
• pp.648-652
• /
• 1994

Lower Arm은 전차축식 현가장치에 사용되는 자동차부품으로 바퀴에서 발생되는 제동력이나 코너링력 등을 지탱하는 장치이다. V형의 상하 2개의 서스펜션암의 축에 의해 츠레임에 장착되고 좌우에 있는 Lower Arm끝부분은 볼조인트 및 부싱에 의해 스티어링 너클에 부착된다. 압입부품들은 자동차의 주행중 발생하는 외력에 의하여 이탈될 수 있는 위험성에 항상 노출되어 있어 자동차에 사용하는 압입부품들의 이탈력은 매우 중요하지만 한번 이탈시킨 Lower Arm은 이탈력이 현저히 저하되기 때문에 이탈력 측정에 의한 품질관리는 전량검사가 불가능하게 된다. 본 연구는 Lower Arm에 압입되는 볼조인트의 압입력을 압입거리에 따라 측정하여 Lower Arm에 뚫어진 볼조인트 압입구멍의 크기와 압입력의 상관관계를 실험적으로 구할수 있는 크기와 압입력의 상관관계를 실험적으로 구할 수 있는 모니터링 시스템을 개발하고자 한다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 1998.04a
• /
• pp.34-39
• /
• 1998

In order to compute the forces which are transmitted through rubber bushings with a commercial multibody dynamic analysis (MBDA) program, a rubber bushing model is needed. The rubber bushing model of MBDA programs such as DADS or ADAMS is the Voigt model which is simply a parallel spring-viscous damper system, meaning that the damping force of the Voigt model is proportional to the frequency. However, experiments do not necessarily support this proportionality. Alternatively, the viscoelastic characteristics of rubber bushings can be better represented by the complex stiffness. The purpose of this paper is to develop a viscoelastic rubber bushing model for the MBDA programs. Firstly, a methodology is proposed to calculate the complex stiffness of rubber bushings considering static and dynamic load conditions. Secondly, a viscoelastic rubber bushing model developed which uses standard elements provided by DADS. The proposed methods are applied to the rubber bushings of the lower control arms of a rear suspension of a 1994 Ford Taurus model. Then, the forces computed for the rubber bushing model are analyzed and compared with the Voigt model in time and frequency domains.