• International Journal of Automotive Technology
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• 제8권5호
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• pp.599-603
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• 2007

An efficient optimum design process has been developed and applied to systematically design a lock-up clutch system for a torque converter used in an automatic transmission. A simulated annealing algorithm was applied to determine the parameters of the compressive helical damper springs in the clutch. The determination of the number, location, a number of turns, and deflection of damper springs plays an important role in reducing vibration and noise in the lock-up system. Next, FE-based shape optimization was coded to find the shape of the clutch disk that would satisfy the strength, noise and vibration requirements. Using the optimum code, parametric studies were performed to see how spring diameters and frequencies of clutch systems changed as the damper spring traveling angles and the torques were varied. Based on the optimum results, five different designs for clutches with different springs were fabricated and vibration analyses and tests were conducted to validate the accuracy of the proposed method. Results from the two methods show a good correlation.

• 한국축산시설환경학회지
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• 제7권2호
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• pp.119-126
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• 2001

For the odor test, it was chosen the conventional spreader, the hose spreader, and its combination with disk harrow and spring harrow as a slurry spreader. By the odor tester (Kalmor-$\sum$) with dairy slurry, the conventional spreader has the average $\sum$ value of 270, which means that one fells substantial odor and torment. In the cases of hose spreader and its combination with disk harrow, $\sum$ value was 217 and 182 respectively, which means a normal person does not smell any odor. Spreading the swine slurry with a conventional spreader shows $\sum$ value of 440, which means one feels unpleasant. The hose spreader shows $\sum$ value of 258, which lies in the limit one feels some odor and torment. Its combination with disk harrow has $\sum$ value 184, which means that a normal person can not smell any more. For the conventional spreader, the odor intensity indices from air dilution sensual test and 3 point odor bag as a sensual test were 66.9 and 35.4 respectively. On the other hand, the indices were 9.65 and 11.10 by hose spreader and its combination with disk harrow, which were lower than that of the regulation for industry. Therefore, the developed hose spreader showed an excellent effect on decreasing odor. The correlation between the results from odor tester and 3 point odor bag has shown 0.997 by swine slurry.

• 한국자동차공학회논문집
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• 제3권4호
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• pp.19-29
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• 1995

This paper discusses the stick-slip phenomenon of the driveline system of a vehicle in consideration of friction. Friction is operated on the between of flywheel and clutch disk. The expressions for obtaining the results have been derived from the equation of motion of a three degree of freedom frictional torsion vibration system which is made up driving part(engine, flywheel), driven part(clutch, transmission) and dynamic load part(vehicle body) by applying forth-order Rungekutta method. It was found that the great affect parameters of the stick-slip or stick motion were surface pressure force between flywheel and clutch disk, time decay parameter of surface pressure force and 1st torsional spring constant of clutch disk when driveline system had been affected by friction force. The results of this study can be used as basic design data of the clutch system for the ride quality improvement of a car.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.409-410
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• 2006

In this study, the tempering effect on the wear characteristics of induction-hardened SPS5 steel was investigated. For this purpose, three tempering conditions were applied to control the hardness of heat-treated SPS5 steel. Ball-on-disk wear tests have been performed using zircornia balls on the tempered specimens to determine the variation of wear characteristics. The results showed that friction coefficient decreased with increasing hardness for induction hardening conditions. This seems to occur because real contact area between specimen and mating ball was affected by the specimen hardness.

• Tribology and Lubricants
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• 제12권2호
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• pp.55-64
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• 1996

Frictional characteristics with the change of loading method and normal stiffness at dry sliding surfaces were experimentally and theoretically evaluated in this study. For the study, a ball-on-disk typed test rig was built and implemented, which allowed a proper selection of loading mechanism and normal stiffness of the test rig. Loading method were varied from dead weight to pneumatic cylinder and spring loading, and the normal stiffness was varied by a spring of different stiffness. Test results showed that frictional characteristics at various loading methods were different even though the operating variables were the same. Discrepancy in the frictional characteristics, such as coefficient of friction and fluctuation in the normal load, were explained by the change in dynamic parameters of the test rigs. Results also showed that coefficient of friction, which defines as a ratio of frictional force divided a normal load, could be differently evaluated in the calculation when fluctuation in the normal load was significant.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 춘계학술대회논문집
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• pp.283-288
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• 2006

This study developes the vibration model to estimate the vibration energy of damper/spring assembly(mainbase assembly) for car CD player, and this model is verified by experiment. From frequency response, response, we investigate the natural frequency and mode shape in the up/down direction. In order to determine the analysis frequency band, we investigate the excitation frequency from the vehicle test. As the characteristics of damper and spring is changed, we carry out the vibration test(transmissibility) and investigate the change of transmissibility.

• 한국생산제조학회지
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• 제24권3호
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• pp.263-269
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• 2015

Growing concerns regarding air pollution have recently increased the demand for liquefied natural gas (LNG) fueled ships. LNG-fueled ships are equipped with an explosion relief valve in the crankcase to relieve excessive pressure and stop flames from emitting from the crankcase. In this study, a finite element analysis was conducted to evaluate the crankcase relief valve disk spring design using an ANSYS Workbench, v.15. The setting pressure, leak and explosion test performed by european standard EN14797 to evaluate function and mechanical integrity of crankcase relief valve. The tests results indicate that the pressure of the crankcase relief valve is 3.05 bar, with no air leakage at 2.97 bar. Finally, the mechanical integrity of the crankcase relief valve was confirmed through an explosion test in which the valve plate assembly, flame arrester, and other parts were safe from fracturing.

• 한국소음진동공학회논문집
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• 제26권6_spc호
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• pp.680-686
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• 2016

In an optical disc archive system, disc insertion process is an important part. Furthermore, dynamic analysis with the contact area between multi-bent leaf spring and a disc should be considered because the contact area is moved when the disc is inserted into the cartridge. In this paper, a finite element model of disc insertion was constructed based on dynamic characteristics, vertical stiffness, and dynamic response. The disc insertion model was validated with the experimental results. To identify the dynamic response of the disc induced by the changed contact area, applied force to the disc and the stiffness of the multi-bent leaf spring were analyzed. As the results, the factors which cause the failure of the disc insertion were investigated.

• 에너지공학
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• 제8권1호
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• pp.143-149
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• 1999

The mounting technology of ceramic candle elements utilizing disk spring was tested in a hot bench unit. Seven SiC candle elements were fixed in three groups by 2, 2, and 3 elements per group. And its performance was investigated in a hot gas stream using oil burned-exhaust gas. The experimental results showed that this mounting method gave a good performance enough to be useful for the particulate removal in the integrated gasification combined cycle (IGCC). Some operational characteristics of the groupfilter were observed.

• 한국소음진동공학회논문집
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• 제15권3호
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• pp.251-258
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• 2005

The free vibration of a spinning flexible disk-spindle system supported by hydro dynamic bearings (HDB) in an HDD is analyzed by FEM. The spinning flexible disk is described using Kirchhoff plate theory and von Karman non-linear strain, and its rigid body motion is also considered. It is discretized by annular sector element. The rotating spindle which includes the clamp, hub, permanent magnet and yoke, is modeled by Timoshenko beam including the gyroscopic effect. The flexible supporting structure with a complex shape which includes stator core, housing, base plate, sleeve and thrust pad is modeled by using a 4-node tetrahedron element with rotational degrees of freedom to satisfy the geometric compatibility. The dynamic coefficients of HDB are calculated from the HDB analysis program, which solves the perturbed Reynolds equation using FEM. Introducing the virtual nodes and the rigid link constraints defined in the center of HDB, beam elements of the shaft are connected to the solid elements of the sleeve and thrust pad through the spring and damper element. The global matrix equation obtained by assembling the finite element equations of each substructure is transformed to the state-space matrix-vector equation, and the associated eigen value problem is solved by using the restarted Arnoldi iteration method. The validity of this research is verified by comparing the numerical results of the natural frequencies with the experimental ones. Also the effect of supporting structures to the natural modes of the total HDD system is rigorously analyzed.