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431.
B. Kim Y. Kim D. M. Chun S. H. Ahn J. D. Jang 《International Journal of Automotive Technology》2009,10(1):73-77
Improving the durability of an automotive V-belt pulley, which is commonly used in an automotive powertrain to transfer power
to other parts, is discussed. Fatigue life of the original V-belt pulley is predicted based on damage analysis by finite element
analysis (FEA). Stress history of the pulley during operation was found by performing consecutive static analyses on the pulley
as the pulley rotates. Assembly load (due to the tightening of the bolts) and operation load were considered to describe the
actual load conditions in a durability test. The contact condition from the belt was calculated and applied to the surface
of the pulley. Static analyses at 36 different positions of the pulley, every ten degrees of rotation, were performed to determine
the stress history of the pulley during operation. Using stress history data calculated from FE analysis, damage over one
rotation of the pulley was calculated and fatigue life, in number of rotations to failure, was estimated. An improvement to
the durability of the pulley was investigated by modifying the design of the pulley using FE analysis results. Durability
tests for the pulleys used in the analysis were carried out to verify the analytical results. Comparison between analysis
and experimental results showed that analytical results correlated with the experimental results closely. 相似文献
432.
The vibrational characteristics of automotives during idling were studied experimentally by considering the axial forces of
the drive shaft and the spider positions in a constant-velocity joint. The generated forces, such as PF (plunging force) and
GAF (generated axial force) in the assembly of the drive-shaft module, were measured directly by an experimental apparatus.
Measurements of the GAF and PF did not show the same trends as the joint angles. They depended instead on the types of CV
joints. In addition, the relationship between the offset values of the shaft and the spider positions in the tulip of the
constant-velocity joint were studied. As a result, the idle vibration characteristics were affected by the variation of the
spider positions and the vibrational characteristics in the axial direction of the shaft, including the amplitude and the
harmonic periods. 相似文献
433.
Partial range scaling method based washout algorithm for a vehicle driving simulator and its evaluation 总被引:2,自引:0,他引:2
M. S. Kim Y. G. Moon G. D. Kim M. C. Lee 《International Journal of Automotive Technology》2010,11(2):269-275
Unlike an actual vehicle, a vehicle driving simulator (VDS) has limited kinematics, workspace, and bounded dynamic characteristics
making it very difficult to simulate dynamic motions of an actual vehicle. To solve these problems, a washout algorithm was
developed. The developed algorithm restricts the workspace of the VDS to within the kinematic limit and makes the person driving
the VDS perceive movement of an actual vehicle. However, the classic washout algorithm contains several problems, such as
time delay and the generation of a wrong motion signal caused by characteristics of the filters. So the driver feels “simulator
sickness,” such as fatigue, nausea, headache and so on because of differences between the sense of movement of the VDS and
that of a real vehicle. In this paper, a partial range scaling method based washout algorithm, including a tilt coordination
system, is developed to enhance the perception of motion and reduce simulator sickness. It is verified by a simulation, a
survey, and a bio signal analysis using an electrocardiogram (ECG). 相似文献
434.
S. I. Kim G. H. Lee J. J. Lee J. P. Hong 《International Journal of Automotive Technology》2010,11(2):277-282
In this paper, a simple design method for improving the performance of an interior permanent magnet synchronous motor (IPMSM),
for driving the air-conditioning compressor used in hybrid electric vehicles, is presented. There are many design methods
that optimize the IPMSM. Each method deals with a variety of design factors, such as slot opening, pole arc, and rotor shape.
However, as the number of design variables increases, a lot of modeling and analysis time is needed in order to improve the
characteristics of an IPMSM. This paper demonstrates that the optimization of a double-layer IPMSM, satisfying the given design
conditions, is possible with only a flux barrier shape design. Then, response surface methodology is applied as the optimization
method, and the validity of the design approach is verified by comparison with test results. 相似文献
435.
提出了用低成本的单个数字信号处理器(DSP)控制多个单相功率因数补偿(PFC)模块的新方案.该方案允许不同电流额定值的多个模块并联工作,并通过单个DsP控制.基于DSP的控制,易于分流,设备小巧.文章叙述了每个PFC模块电流的测量技术和多个模块工作的输出电压和输入电流闭环控制方法.在该设计例子中,开关频率设定为120kHz,2级连续导通模式的PFC并联工作,并由单个TMS320LF2407DSP控制.实验结果表明,现代开关电源可采用该方案. 相似文献
436.
Hyuk Kim Graduate student Yong-San Yoon Professor Ph.D 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》1995,24(10):759-780
The objective of this study is to develop a control law for a semi-active suspension for the purpose of ride quality improvement. The semi-active control law is determined by reproducing the control force of an optimally controlled active suspension while suppressing its damping coefficient variation. The performance index of the optimal control for the active suspension is modified to include frequency-shaping by use of Parseval's theorem, which allows us to de-emphasize the effects of particular variables over specific frequency bands.
Through the numerical simulations, it was found that the semi-active suspension may reduce the vertical acceleration of the driver's seat and the sprung mass motions significantly. The road-holding and tire deflections were not affected much. 相似文献
Through the numerical simulations, it was found that the semi-active suspension may reduce the vertical acceleration of the driver's seat and the sprung mass motions significantly. The road-holding and tire deflections were not affected much. 相似文献
437.
438.
C. Hein S. Hong J. Suh H. Hoffmann N. Kim 《International Journal of Automotive Technology》2008,9(2):211-216
It is essential to develop efficient and cost-effective production methods to achieve or maintain international competitiveness.
An innovative production method, such as rotary blanking, enables manufacturers to both reduce expenses and economize production
time. However, there are not enough numerical analyses for this process. In this paper, numerical simulations of rotary blanking
were performed. After comparing the cutting planes generated by conventional and rotary blanking experimental tests, the cutting
areas of two punch geometries were analyzed. The influence of punch geometry on part quality was then investigated through
simulations. The procedure for die stress analysis was established and stress distributions of the worksheet and the tools
were analyzed. 相似文献
439.
When soot particles are loaded in a diesel particulate filter, it causes increase in back pressure of the exhaust system.
To minimize this pressure drop due to DPF, the filter needs to be regenerated after a certain amount of soot has been accumulated.
It is crucial to estimate the correct amount of soot that has been accumulated by measuring the differential pressure. It
is also important to understand changes in pressure drop due to flow rate variations of the exhaust gas, since the pressure
drop would be influenced by the exhaust flow rate as well as the amount of soot. Furthermore, the heat transfer characteristics
of the catalyzed diesel particulate filter (CDPF) are another major issue, as the filter is occasionally exposed to high temperature
gas. This study presents the characteristics of pressure drop according to the variation of soot loading and the mass flow
rate in CDPF. In addition, heat transfer characteristics in the filter was investigated when a high temperature gas flows
into the CDPF. Tests were performed in several CDPF samples having varying amounts of catalyst coating. Experimental results
indicate that rig-based experiments are useful in understanding the characteristics of pressure drop in the CDPF. In the cake
filtration region, a pressure drop has a proportional relationship according to soot loading and mass flow rate. It was found
that an increased catalyst coating may lead to enhanced convective heat transfer. 相似文献
440.
J. Kim 《International Journal of Automotive Technology》2008,9(6):687-693
In this article, the analysis methods for vehicle handling performance are studied. Using simple models, dynamic characteristic
parameters such as yaw, natural frequency, and the damping coefficient of a vehicle can be theoretically formulated. Here,
the vehicle is simplified by a bicycle (single-track) model, and the tire is modeled by an equivalent cornering stiffness
and first order lag. From the experimental road data, the tire model parameters (equivalent cornering stiffness and time lag
constant) are extracted. These parameters are then inserted into the theoretically formulated equations of dynamic characteristic
parameters. For the purpose of validating the efficiency of the suggested methods, experimental road tests (where the cars
have different handling performances) are performed. The results show that vehicle handling performance can be sufficiently
represented by the suggested dynamic characteristic parameters. So, it is concluded that the proposed method has practical
use for the development of new cars or for the comparison of similar cars since the evaluations of the vehicle handling performance
can be efficiently determined by the suggested dynamic characteristic parameters. 相似文献