• Proceedings of the KSR Conference
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• 2000.11a
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• pp.484-490
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• 2000

The freight wagon with weld fabricated 1-piece bogies, which was developed to increase operating speed, reveals its difficulties in maintenance. The weld-fabricated bogies were composed of two-stage coil spring and dry friction damping mechanism. The inborn wear parts and rather complicated structure mattes bogie maintenance difficult. In order to relieve this difficulties, the application of maintenance free rubber suspension is proposed by bogie maunfacturer, Taeyang Precision Limited. This study was conducted to determine design parameters of proposed rubber suspension by means of vehicle dynamic simulation and parametric study. The target critical speed of bogie was set over 150km/h for the preparation of further speed-up of freight wagon.

• Proceedings of the Korean Society For Composite Materials Conference
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• 1999.04a
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• pp.29-33
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• 1999

this paper concerned with the stress analysis of a diaphragm-type air spring which consists of rubber linings nylon reinforced rubber composite. The analysis is carried out with a finite element method developed to consider the orthotropic properties geometric non-linearity and contact between an air bag and a bead ring The material properties are evaluated with the Halpio-Tsai equations and the rule of mixture. The analysis results demonstrate the variation of the outer diameter the fold height and the vertical force with different models to the design a proper diaphragm air springs.

• KSTLE International Journal
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• v.1 no.1
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• pp.43-47
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• 2000

Oil seals will experience a small amplitude dynamic excitation due to the shaft eccentricity as well as out-of-roundness of the shaft. The direct integration method is selected to analyze the time domain response of the seal lip-shaft contact. The physical properties of rubber seal materials are experimentally analyzed. Effects of both frequency and temperature on the material stiffness behavior are investigated for the linear viscoelastic materials of the seal. Using the nonlinear transient model, a finite element analysis of the lip-shaft contact behaviors under dynamic conditions is presented as a function of the shaft eccentricity, the shaft interference and the garter spring stiffness. The FEM results based on the experimental data indicate that the increased rotating speed may produce the separation conditions. These results will be very useful in predicting the leakage of oil seals under dynamic conditions.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2002.11a
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• pp.237-332
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• 2002

We constructed ceiling structure and floor structure for elevation of sound insulation performance of concrete slab of apartment house. And, we wished to measure heavy floor impact sound level and light floor impact sound level of these structure. As the result, light floor impact sound level interception performance of concrete slab was measured by thing that construction work of gypsum baud is important. Heavy floor impact sound level interception performance was measured by thing that it is effective that construct to thickness about 30 millimeters on concrete Slav. It was measured effectively that heavy floor impact sound level interception performance constructs rubber chip to thickness about 30 millimeters on concrete Slav.

• Aerospace Engineering and Technology
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• v.7 no.1
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• pp.170-176
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• 2008

The concept design of Flexible Seal for thrust vector control of solid motor was performed. Through the concept design, the optimum pivot point of flexible seal, cross-section configuration of flexible seal and thermal protection system from combustion gas was decided. The pivot point of flexible seal has aft pivot type and cross-section view is conical type. For satisfying a spring torque rate, the shear modulus of rubber has the value of under about 0.6MPa and failure shear stress has over about 2.5MPa.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.689-693
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• 1997

This paper deals wth the impact and the transient analysis of the impact absorbing system consist of double damping. piston and sprlng system in spreader to increaas efficlcncy of it. It shows the optimum damping coefficient and spring constant under the limited stroku of Impact absorbing system using for crane spreader and the optimum condition of impact absorbing system causing certain reaction force as time. which is characteristic of dashpot and rubber. This system absorbed 11.5 and 88.5 % impact energq at the spring and the damper respectively.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.6
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• pp.1559-1566
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• 1994

Using the finite element method, the contact force, contact band width and temperature distribution of lip seals analyzed for the interference including some nonlinearities such as material nonlinearity, geometrical nonlinearity and nonlinear contact boundary condition. The calculated results showed that the contact stress concentrated on the contact zone between the garter spring and the rubber toward the flex side, the contact edge of lip seals. The high contact forces due to the increased interference separate the sealing gap between the lip edge and the rotating shaft. This may lead to leak the sealed oil.

• Transactions of Materials Processing
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• v.24 no.6
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• pp.387-394
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• 2015

Air springs are designed to support loads using the volume elasticity in a cylindrical shaped air bag made of a composite material with a rubber matrix and two plies of reinforced fibers. Recently, applications of these springs have been expanded from railway vehicles to passenger cars. The current study presents a finite element analysis of a manufactured air spring for a passenger car. The analysis was conducted including the mounting steps of the air bag using a static loading condition. A method for controlling the internal pressure and displacements during the mounting step was developed. The characteristic load curve and the shape of the air bag were in good agreement with the experimental data with respect to the design height, the bump height and the rebound height. Results indicate that ply angles of fibers vary from 38 degrees to 56 degrees during static loading.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.5
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• pp.164-170
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• 2008

A typical clutch system for automotive manual transmissions transfers hydraulic pressure generated by driver's pedal manipulation to the clutch diaphragm spring. The foot effort history during the period of push is different than the period of the clutch pedal's return. The effort or load difference is called clutch foot effort hysteresis. It is known that the hysteresis is caused by friction. The frictional force and moment are produced between various component contact points such as between the rubber seal and the inner wall inside the hydraulic cylinder and between the diaphragm spring and the pressure plate, etc. Understanding the clutch pedal foot effort hysteresis is essential for a clutch release system design and analysis. The dynamic model for a clutch release system is developed for the foot effort hysteresis prediction and a simulation analysis is performed to propose a tool for analysing a clutch system.

• Proceedings of the KSME Conference
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• 2001.06b
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• pp.507-512
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• 2001

As needs for substitution of excessive road-oriented transport by the railroad increase, we proposed the guideline for development of the high speed freight car up to 150km/h through analyzing the critical speed of welded-type freight car employed and investigating the improvement in its maintenance. This study, the proper design parameters of conical rubber spring was determined to meet the vibration performance.