• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.4
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• pp.271-277
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• 2017

In this paper, the amplitude and frequency dependent dynamic characteristics of the equivalent stiffness of a rubber bushing are investigated. A new mathematical model is proposed to explain the large deformation and size effect of a rubber bushing. The proposed model consists of elastic, viscous, and frictional stress components and the equivalent strain. The proposed model is verified using experimental results. The comparison shows that the proposed model can accurately predict the equivalent stiffness values of a rubber bushing under various magnitudes and frequencies. The developed model could be used to predict the dynamic equivalent stiffness of a rubber bushing in automotive engineering.

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

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.3
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• pp.303-309
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• 2015

In this study, a vehicle dynamic analysis and roller rig test were performed to evaluate the applicability of a suspensionless composite bogie to railway vehicles. A vehicle dynamic analysis was carried out under different rubber bushing stiffness values. The stiffness of the rubber bushing that plays a role in guiding wheel sets was varied in the range of 10-100 MN/m, in 10-MN/m steps. Based on the results, the composite bogie with a rubber bushing stiffness of more than 40 MN/m satisfied the design requirements. In addition, a rubber bushing with a stiffness of 81 MN/m was fabricated, and a roller rig test was performed. Based on the test results, the vehicle equipped with the composite bogie had a critical speed of 363 km/h, which agreed with the simulation result within an error of 10%.

• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.5
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• pp.186-193
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• 1999

In this paper, a full vehicle model is developed to analyze toe and camber changes due to rack height variation and compliance. The AutoDyn7 program developed in G7 project is used for the computer simulation. Steady state cornering test was done to find the understeer gradient. Imposing a pulse steer input, Frequency Response Function(FRF) of yaw rate and lateral accelerations were evaluated. To verify the stability, the rhombus using four parameters is employed. Steer characteristics were evaluated by changing the rack height and the bushing lateral stiffiness. which installed between the low control arm and the chassis.

• Journal of the KSME
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• v.54 no.2
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• pp.41-45
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• 2014

이 글에서는 조인트, 부싱, 댐퍼 그리고 구동기 등으로 연결된 일반적 다물체계의 질량, 강성, 감쇠, 기하학적 제원 등에 존재하는 불확실성의 영향을 동적 해석 및 설계 시 어떻게 체계적으로 고려해야 하는지 대표적인 방법을 중심으로 관련 내용을 소개하고자 한다.

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