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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Transactions of the Korean Society of Automotive Engineers
Journal Basic Information
Journal DOI :
The Korean Society of Automotive Engineers
Editor in Chief :
Volume & Issues
Volume 7, Issue 9 - Dec 1999
Volume 7, Issue 8 - Nov 1999
Volume 7, Issue 7 - Sep 1999
Volume 7, Issue 6 - Aug 1999
Volume 7, Issue 5 - Jun 1999
Volume 7, Issue 1 - 00 1999
Selecting the target year
Estimation of Particulate Loading in Diesel Particulate Trap System
Jo, Hun ; Kim, Jae Eop ; Kim, Hyeong Uk ; Kim, Eung Seo ;
Transactions of the Korean Society of Automotive Engineers, volume 7, issue 1, 1999, Pages 1~1
A diesel particulate trap system has recently been studied to meet stringent diesel exhaust gas regulation. This research has been focused on the estimation of particulate loading, one of the most important subjects to develope trap system, through investigating the flow characteristics of ceramic cordierite filter and the particulate layer. The permeability of ceramic filter is estimated using Darcy's law through cold rig test. It is established by cold rig test that the linearity between the pressure drop and the gas velocity through the filter medium and the particulate layer. The particulate loading parameter is derived from this relation, the linearity between the pressure drop and the gas velocity according to the particulate loading mass, through engine test. Using this \loading parameter, it is possible to estimate the mass of particulate collected inside the filter within ±20% during the transient engine operation.
Measurement and Analysis of Instantaneous Surface Temperature and Unsteady Heat Flux at Combustion Chamber of DOHC Gasoline Engine;Cylinder Head
Jo, Jin U ; Ryu, Yeong ; Lee, Jong Tae ;
Transactions of the Korean Society of Automotive Engineers, volume 7, issue 1, 1999, Pages 10~10
The instantaneous surface temperature and unsteady heat flux on the cylinder head are measured and analyzed in order to obtain the basic data for the design at the combustion chamber of DOHC engine . The main results are as follows ⅰ) The highest wall temperature is shown at vicinity of the exhaust valve bridge and the temperature of the exhaust valve bridge is continuously increased in the exhaust stroke. ⅱ) The wall temperature at the exhaust valve head is about twice as high as that of the intake valve head. ⅲ) The distribution of the heat flux has different tendency to that of the wall temperature and the heat flux of the exhaust valve bridge has a small value comparatively.
A Study on the Performance of a High Temperature and High Pressure Constant-Volume Combustion Chamber for Modelling of Soot Formation Processes in Combustion Engines
Bae, Myeong Hwan ; Lee, Seung Gyu ;
Transactions of the Korean Society of Automotive Engineers, volume 7, issue 1, 1999, Pages 20~20
Comparison of the Sauter Mean Diameter Measured by Fraunhofer Diffraction Method and Phase Doppler Method
Kim, Sang Jin ;
Transactions of the Korean Society of Automotive Engineers, volume 7, issue 1, 1999, Pages 31~31
Among the optical sizing methods which have been developed for the measurement of a spray droplet size, the laser diffraction method and the phase Doppler method are using widely. For the comparison of the Sauter mean diameter obtained from these two methods, sprays of twin-fluid atomizers and humidifier at the same injection conditions were measured. Although the spray at a same injection conditions were measured, the Sauter mean diameters measured by the laser diffraction method and the phase Doppler method was not same. We could put the Sauter mean diameter difference by these two methods in order by a droplet size distribution.
Numerical Simulation of Swirling Turbulent Flows in the Cylinder of a Diesel Engine
Lee, Seung Yeop ; Choe, Yeong Don ;
Transactions of the Korean Society of Automotive Engineers, volume 7, issue 1, 1999, Pages 38~38
In this study, a computational code was newly developed in which a three dimensional body-fitted moving grid system was adopted and also the physical contravariant components were taken as the dependent variables. The present code was applied to the intake and compression process in a toroidal bowl-in-piston chamber. The transient calculation of the flow fields and the global analysis in the chamber revealed the generation, distortion and corruption of the swirling and tumbling vortices and those influences on turbulence kinetic energy. A strong interaction was found between the shape and position of the bowl and the swirling turbulent flow. It was also observed that the squish flow generated by the existence of the bowl reincreased the swirl ratio and showed the "spin-up" of tumble ratio during compression stroke.
A Study on the Fuel Behavior Characteristics Injected in the Intake Pulsating Air Flow
Lee, Gi Hyeong ; Lee, Chang Sik ; Jeong, Jae U ;
Transactions of the Korean Society of Automotive Engineers, volume 7, issue 1, 1999, Pages 50~50
Since the fuel behavior injected in the intake manifold of MPI gasoline engine is effected by pulsating air flow, the fluctuated air flow generator that can simulates the air flow in an actual engine is designed and produced. Using these apparatus, fuel behavior characteristics injected in the pulsating air flow in an intake manifold under various injection timing and injection duration are measured by the hot-wire anemometer and PMAS. From these experiments, fuel injection conditions such as injection timing, injection duration and spray pattern injected from MPI injector are made clear. The goal of this research would be to give a design guide for optimal fuel injection system.
An Experimental Study on the Measurement of the Instantaneous Temperature of the Combustion Chamber Walls of the DI Mono Diesel Engine, and the Calculation of the Heat Transfer through Piston Rings
Lee, Jae Sun ; Choe, Gyeong Gwan ; Jeong, In Gon ;
Transactions of the Korean Society of Automotive Engineers, volume 7, issue 1, 1999, Pages 59~59
In this study, the instantaneous temperature probes were developed for the experimental measurement of instantaneous surface temperature on the combustion chamber walls of the DI mono cylinder dies el engine. The heat flux were measured on the cylinder head, piston crown and cylinder liner. The heat quantity flowing out to the cylinder liner through the piston rings could be calculated using the measured temperature data of both piston rings and liner. Cylinder liner receives heat from both sources one is from the combustion gas and the other is from the piston rings. The percentage of heat from the rings was almost the same as that of from the combustion gas.
Combustion Characteristics of Plasma Jet Ignition on LPG-Air Mixture in Laminar Flow Field
Park, Jeong Seo ; O, Byeong Jin ; Kim, Mun Heon ;
Transactions of the Korean Society of Automotive Engineers, volume 7, issue 1, 1999, Pages 68~68
Experimental investigation of the effects of a plasma jet ignition on LPG-air mixture was executed in laminar flow field. Plasma jet ejection forms highly turbulent ignition surface in the initial stage of combustion. And by the plasma jet ejection into the center of combustion chamber, flame fronts have spherical shape as central ignition type. From the result of the visualization, it shows that the plasma jet ignition causes faster burn than conventional spark ignition. And also the lean limits are extended, the combustion enhancement effects of plasma jet ignition are shown compared to conventional spark ignition. But in case of the lean fuel-air equivalence ratio φ=0.6, the initial flame is separated from the plasma jet plug, therefore extensibility of lean limit will be restricted by this phenomenon in real engine combustion chamber with turbulent motion.
A Study of Flame Propagation in a Spark Ignition Engine using Ionization Probes
Park, Su Yeol ; Jeon, Gwang Min ;
Transactions of the Korean Society of Automotive Engineers, volume 7, issue 1, 1999, Pages 77~77
Flame propagation in a spark-ignition engine is measured using an ion-probe technique for various loads, spark timings and fuel air ratios. Ion-probes were installed in a piston to measure the main flame propagation and lead wires from the ion-probes were connected to a computer through a linkage. Flame development at 1,500rpm, part load condition were measured. The results showed that flame propagates faster in the exhaust valve region than in the intake region and the propagation speed increased in the later stage as spark timing is advanced. The leaner air-fuel ratio had stronger effect on the intake valve side flame development than the exhaust valve side. Also, flame radius is calculated using the turbulent flame propagation model. There is a little difference between measured and calculated values, but the tendency of the flame propagation was similar.
Effect of Transfer Port Shapes on the In-Cylinder Flow in a 2-Stroke Engine
Lee, Eun Ho ; Yu, Jae Seok ; Lee, Jong Hwa ;
Transactions of the Korean Society of Automotive Engineers, volume 7, issue 1, 1999, Pages 86~86
The performances of two-stroke engine mainly depend on scavenging process. The geometry of the transfer ports, which govern the characteristics of scavenging process, is dominant design parameters in a loop scavenging type two stroke engine. In this study, the effects of the design parameters such as transfer port angles (AM1, AM2) and up-sweep angle(UPM) on the scavenging process are studied by Jante method and in-cylinder flow velocity measurements. As transfer port angle(AM2) and up-sweep angle(UPM) increases, the magnitude of scavenging velocity is decreased. And the transfer port angle, AM1, gives heavy influence on the scavenging flow pattern while the transfer port angle, AM2, and up-sweep angle(UPM) give weak influence on it relatively. Therefore, in the design of transfer port, AM1 should be decided first in view of the scavenging flow pattern. And then, the scavenging flow velocity should be optimized by AM2 and UPM.
Analysis of In-Cylinder Unsteady Bulk Flow in DOHC 4-Valve Engine
Lee, Chang Sik ; Lee, Gi Hyeong ; Jeon, Mun Su ; Kim, Yeong Ho ;
Transactions of the Korean Society of Automotive Engineers, volume 7, issue 1, 1999, Pages 99~99
This study describes the analysis of in-cylinder unsteady bulk flow in dual-intake-valve engine by using the laser sheet method and single frame particle tracking velocimetry(PTV). In order to investigate the visualization and application of optical system, a gasoline engine with four cylinders was modified into single cylinder visualization engine. Comparing the maximum pressure and mass flow rate of modified engine with base engine, the modified visualization engine is good enough to be used to analyze in-cylinder flow. Flow visualization indicated that various large and small vortex were appeared at induction stroke and the flow inducted through the right side of intake valve headed to exhaust port. The results of PTV shoed that in-cylinder mean and maximum velocity is 2.60m/s and 8.10m/s respectively at BDC which are 2.2 and 6.9 times of average piston speed. And the mean flow velocities are investigated for the analysis of gas flow in cylinder during induction and compression stroke.
The Effect of Piston 2nd Land Geometry on the Oil Consumption
Choe, Jae Gwon ; Lee, Sang Won ; Min, Byeong Sun ; Jo, Yeong U ;
Transactions of the Korean Society of Automotive Engineers, volume 7, issue 1, 1999, Pages 109~109
The effects of the piston 2nd land volume and the hole from 2nd land to undercrown were investigated. Oil film thickness, ring motion and 2nd land pressure were analyzed to accomplish that. The oil film thickness between ring and liner was measured by capacitant technique to verify the calculated results. The increase of 2nd land volume reduces oil consumption. It is because of the change of oil film thickness rather than ring motion and blow-up gas rate. The difference of oil film thickness between intake-stroke and compression-stroke is proportional to oil consumption. The left behind oil during expansion-stroke is also proportional to it. The 2nd land hole was expected to reduce oil consumption because it decreases the 2nd land pressure and stabilized the axial motion of top ring. However, a counter result was obtained at the actual test, so it was found out that the effect of blow-down is significant as well as that of oil film thickness.
Experimental Study on the Trial Manufacture of Small Capacity Torque Transducer
Kim, Gap Yong ; Kim, Du Man ;
Transactions of the Korean Society of Automotive Engineers, volume 7, issue 1, 1999, Pages 116~116
In this study, with usual gauge, a domestic product of small capacity torque transducers was attempted through trial manufacture. The prediction for characteristic of the torque transducers trial manufactured was performed through experiment. Through the experiment, we found that good results were obtained as follows. In rating value 0-500
of torque transducers, precision and accuracy is better 1,500r.p.m. than 3,000r.p.m. by allowable revolution. As natural frequency is 300Hz standard, till 6,000r.p.m. is not difficult. Test power of trial manufactured torque transducers considered till 1
-cm. In measurement of torque transducers, response is very important. As time constant is 0.07 second, good results were obtained. In the future, with experiment for durability is continuous, we want to plan for guarantee
A Numerical Study on the Automotive Torque Converter(Part Ⅲ);Geometries and Performances
Park, Jae In ; Jo, Gang Rae ;
Transactions of the Korean Society of Automotive Engineers, volume 7, issue 1, 1999, Pages 124~124
In the hydraulic design of torque converters, there exist many geometrical parameters to be considered. Each parameter affects the performance of the torque converter. Unfortunately, the effects of the parameters on variations of the performance have been rarely known. In this paper, several geometrical parameters including the meridional configuration of pump and turbine, the edge configuration at pump inlet, the distribution of angular momentum change, the offset angle of turbine, and the treatment for the trailing edge of stator were analyzed by numerical calculations. It was found that the geometrical variations are strongly related with the performances and the internal flowfield of torque converters.
Experimental Study of Line Pressure Electronic Controlled CVT
Song, Han Rim ; Kim, Jeong Cheol ; Kim, Hyeon Su ;
Transactions of the Korean Society of Automotive Engineers, volume 7, issue 1, 1999, Pages 139~139
A CVT with a line pressure electronic control system was developed using PWM solenoid valves based on the mechanical controlled CVT in order to improve the overall efficiency of the CVT hydraulic system. For the line pressure electronic controlled CVT, the optimal line pressure control strategy was suggested considering the driver's desire and driving conditions. Experimental results showed that the line pressure of the electronic controlled line pressure CVT developed in this study can be reduced by 5~18 bar compared with those of the mechanical CVT for the launching test, and by 5~10 bar in the cruising test. It is expected that the reduced amount of the line pressure by the electronic control strategy contributes to the improvement in the CVT system efficiency.
Development of Mini-Bus Ride Analysis Method
Park, Tae Won ; Im, Hong Jae ; Lee, Gi Ho ; Park, Chan Jong ; Jeong, Il Ho ;
Transactions of the Korean Society of Automotive Engineers, volume 7, issue 1, 1999, Pages 149~149
Ride harshness is the important characteristic for a passenger bus. Since ride generally involves frequencies up to 30 Hz, special modelling technique should be used for ride analysis. This paper investigates modelling technique of a passenger bus for ride analysis which involves coupling of rigid bodies and flexible bodies in one model. First step is to build a rigid model and next step is to establish FEM model of a bus body and leaf springs. Then, prepared FEM model is coupled with the rigid model. Computational results of the coupled bus model is compared with the testing results. Then, sensitivity analysis was carried out to suggest the direction for the ride quality improvement.
Design, Fabrication and Testing of a Silicon Microaccelerometer with a Symmetrically Bonded Proof-mass
Go, Jong Su ; Jo, Yeong Ho ; Gwak, Byeong Man ; Lee, Ho Jun ; Park, Gwan Heum ;
Transactions of the Korean Society of Automotive Engineers, volume 7, issue 1, 1999, Pages 155~155
This paper presents the design, batch-fabrication and testing of a piezoresistive cantilever beam microaccelerometer for automobile airbag applications. Silicon proof-mass has been bonded symmetric ally for self-diagnostic capability and zero transverse sensitivity of the microaccelerometer. Microfabrication process, including a simple silicon etch-stop method for beam thickness control has been developed for mass production lines. Fabricated devices show a resonant frequency of 2.15kHz and a sensitivity of 34μV/g/V with a nonlinearity of 2% at 100Hz. The present fabrication processes provide simple, practical and effective means for the reproducibility and mass production of the accelerometers.
An Estimative Model of Spot Weld Failure;2. Panel Structure Analysis
Sin, Su Jeong ; Lee, Hyeong Il ; Lee, Tae Su ; Choe, Yang Uk ;
Transactions of the Korean Society of Automotive Engineers, volume 7, issue 1, 1999, Pages 161~161
The feasibility of a macroscopic approach to spot weld failure in panel structures depends strongly on the accuracy of adopted failure criteria. In this work of "Part 2-Panel Structure Analysis", as a first step to evaluate the feasibility, we demonstrate that finite element analyses can replace the experimental testings in determining the coefficients of the failure equation. Taking advantage of this equivalent role of finite element analyses, we systematically investigate the shape-dependency of failure envelop on the welding parameters and geometries such as spot welding condition, and panel thickness, pitch and radius of nugget. Then, using commercial PAM-CRASH™ code, based on the failure criteria established in Part 1, we perform finite element analyses of the spot-welded panel structures, which simulate the car seat belt anchors. By comparing the predicted failure modes to those observed from the corresponding experimental testings, we finally evaluate the effectiveness and validity of macroscopic approach to the spot weld failure through the criteria in suggested form.
Stress Intensity Factors of an Inclined Surface Crack in a Shaft under Torsion
Yang, Won Ho ; Jo, Myeong Rae ; Sin, Sang Beom ;
Transactions of the Korean Society of Automotive Engineers, volume 7, issue 1, 1999, Pages 173~173
The components with a round cross section are commonly used in engineering structures. The purpose of this paper is to analyze the combined mode stress intensity factors of an inclined surface crack in a shaft subjected to pure torsion by finite element method. The mesh of analysis model is composed of 15-nodes quarter point elements along the crack front to satisfy the singularity and 20-nodes isoparametric elements elsewhere. The stress intensity factors of the crack front are calculated by COD(crack opening displacement) method, CSD(crack sliding displacement) method and CTD(crack tearing displacement) method. The parameters used in this study are the crack slant angle and the crack aspect ratio.
Modeling Technique of a Leaf Spring as Force Element in Vehicle Dynamic Analysis
Kim, Gwang Seok ; Lee, Jeong U ; Yu, Wan Seok ;
Transactions of the Korean Society of Automotive Engineers, volume 7, issue 1, 1999, Pages 181~181
Leaf springs are widely used as a major suspension component in many commercial vehicles. Since friction is present between leaves, these elements have complicate nonlinear characteristics such as a hysteresis behavior, higher stiffness for small deflection behavior. Thus, the modeling technique of a leaf spring is one of the most difficult problems in vehicle suspension modeling. This paper concentrates on the mathematical modeling of leaf spring force using its shape and material properties. The shape of a leaf spring, stiffness matrix, and hysteresis data obtained from experimental test are required. The developed leaf spring force models are implemented as a leaf spring module in the AUTODYN7 program.
A New Double Sky-hook Algorithm for Improving Road-holding Property in Semi-active Suspension Systems
U, Seung Hun ; Ryu, Je Ha ;
Transactions of the Korean Society of Automotive Engineers, volume 7, issue 1, 1999, Pages 192~192
This paper presents a new double sky-hook algorithm for controlling semi-active suspension systems in order to improve road-holding property that the conventional theoretical sky-hook algorithm cannot achieve. The proposed double sky-hook algorithm uses combination of damper coefficients, one from the chassis motion and the other from the wheel motion. Computer simulation using a quarter and a full car dynamic models with the road conditions specified by ISO show the effectiveness of the proposed algorithm. It is observed that the proposed algorithm is the most effective in the vicinity of the wheel hop frequency.
A Study on the Application of Crashworthiness Simulation Models at each Design Stage of Jeep Passenger Car
Kim, Taek ; Min, Han Gi ; Jo, Gyu Jong ;
Transactions of the Korean Society of Automotive Engineers, volume 7, issue 1, 1999, Pages 201~201
The effects and the ability to withstand crash tests are crucial factors to consider during the designing stages of a given vehicle in this case, a passenger jeep vehicle. Taking such factors into consideration during the initial designing stages reduces the time and cost of production and insures the safety of the vehicle. This study is concerned with the application of different crash simulation models at each stage of the design process so to test the degree of safety. As for the results of this study, the acceptable correlation of results were found between the full scale test and the crashworthiness simulation.
Longitudinal Vehicle Platoon Control in Intelligent Vehicle Highway Systems
Won, Mun Cheol ;
Transactions of the Korean Society of Automotive Engineers, volume 7, issue 1, 1999, Pages 209~209
A real time control algorithm for the longitudinal spacing control of vehicle platoons in IVHS is simulated. The longitudinal vehicle dynamics including engine, brake, torque converter, wheels, and tire slip are modeled as liner and non-linear elements. The engine and brake control algorithms based on multiple surface sliding control include adaptive observers and filters that condition measurement signals. The control law used for the real time experiment of four car platoon is simulated for four car and ten car platoon systems. The car to car communication time delays of vehicle velocities and accelerations are included in the simulation. The simulation results of the four car platoon in general agree with the experimental results.
A Basic Study on Static and Dynamic Crushing Behavior of a Stiffened Tube
Baek, Jeom Gi ; Jeong, Jang Yeong ;
Transactions of the Korean Society of Automotive Engineers, volume 7, issue 1, 1999, Pages 219~219
A Study on the Simulation of the Vehicle Shudder Considering the Power Train and the Effects of the Related Parameters on the Vehicle Shudder
O, Seung Tak ;
Transactions of the Korean Society of Automotive Engineers, volume 7, issue 1, 1999, Pages 239~239
The purpose of this study is to simulate the vehicle shudder considering the power train, and to examine the effects of the power train on the vehicle shudder that is caused by the axial force of the tripod joint used in automotive drive shaft. The effects on the vehicle shudder in terms of the design parameters of the tripod joint as well as of the vehicle have already been analyzed by use of the concept of influence factors. However, given that an actual vehicle shudder occurs during a sudden acceleration of a vehicle, which puts the power train under severely varying torque conditions, the simulation that includes the power train is required to provide a more concrete analysis of the vehicle shudder. Thus in this paper, the vehicle modeling with the power train is adopted to simulate the vehicle shudder, and the influence of the power train parameters on the vehicle shudder is investigated. The simulated results show that the vehicle shudder occurs primarily during sudden acceleration, and that it is severely amplified due to the fluctuation of torque applied to the power train, in condition where the front wheels slip or are not on the road. In addition, the parameters affecting vehicle shudder were selected as the difference of the torsional stiffness between the right and the left drive shaft, the total rotational clearance of driveline, and the clutch stiffness, among which the difference of the torsional stiffness between the right and the left turned out to affect vehicle shudder relatively.
The Optimum Design Technique of The Low-Noise Intake System and Improvement of Sound Quality
O, Jae Eung ; Han, Gwang Hui ; Lee, Chang Ho ;
Transactions of the Korean Society of Automotive Engineers, volume 7, issue 1, 1999, Pages 251~251
The intake noise, a major source of the vehicle noise, was studied to reduce the level for many years. Traditionally, the intake noise has been analyzed and improved by the experiments, namely, the trial and error approach. Recently, in spite of various techniques that have been proposed to analyze, the optimum design technique for the low-noise intake system has not been satisfied. The optimum design process that considers the engine performance, the space constraints and the intake noise level simultaneously is proposed by this study. Two optimum specification of the intake system are proposed and verified by a theoretical method. And, the improvement of sound quality for the optimum design is verified by the speaker excitation system.
A Study on Development of Functional & Parametric Tester for Reliability Test of Automotive Electronic Control Unit
Kim, Yeong Sik ; O, Dae Seon ; Yun, Yong Su ;
Transactions of the Korean Society of Automotive Engineers, volume 7, issue 1, 1999, Pages 259~259
The reliability test has been performed to recognize and evaluate the potential failure of product and its effects. For ease of application, the functional test has been generally adapted to determine "Pass or Fail" of product under environmental test to demonstrate its long run-time. However, the parametric test is more useful to ensure the capability of product according to design parameter. In this study, the functional and parametric tester for reliability test of automotive engine control module(ECM) is developed. The parameter of circuit is determined by functionally defined circuit of ECM. The methods are applied for measuring multiple channels and reducing error caused by the harness and connecting point between tester and samples. The result shows that measured signals represent a good estimate of the parameter. In case of the test system, it is expected to improve the accuracy of test result more than functional test after reliability test.
The Application of a Nonlinear Least Squares Method to Predicting Dynamic Stiffness of the Intervertebral Disc
Kim, Yeong Eun ;
Transactions of the Korean Society of Automotive Engineers, volume 7, issue 1, 1999, Pages 270~270
A new method to predict dynamic stiffness of the intervertebral disc was proposed. The influence of frequency sensitive viscoelastic behavior, a main limitation in previous measurements, could be excluded in this analysis. Using the Levenberg Marquardt method, dynamic parameters in disc model have been obtained by curve fitting to measured dynamic stiffness S(ω) values of the disc. Among the several types disc model, three parameter model shows the most close agreement with a measurement for the artificial disc of the head-neck complex dummy in compression mode. Whereas Maxwell model reveals best fit in cases of flexion, extension and lateral bending mode.
Impact of Cracks At and Around Interface of Dissimilar materials
Yang, In Su ; O, Hwan Seop ;
Transactions of the Korean Society of Automotive Engineers, volume 7, issue 1, 1999, Pages 277~277
In this paper, stress intensity factor
of a crack along the straight interface between two dissimilar materials, one of the very important criterion in fracture mechanics, is analysed accurately by boundary element method(BEM) which is known as superior in elastic analysis. Stress intensity factors of a central interface crack in dissimilar materials, a central interface crack and a equal length parallel crack in dissimilar materials, two neighbor interface cracks in dissimilar materials are calculated. It is confirmed that the present results of the stress intensity factor for various interface cracks in finite plate or infinite plate are completely consistent with other results. It is observed that how much do Young's modulus of materials and interference of cracks effect on stress intensity factor of interface crack.
A Study on Vibration Analysis System of Two-Stage Geared System
Jeong, Tae Hyeong ; Myeong, Jae Hyeong ;
Transactions of the Korean Society of Automotive Engineers, volume 7, issue 1, 1999, Pages 284~284
This paper analytically investigates the dynamic behavior of a 2-stage parallel shaft gear system whose power is transmitted by a pair of spur gears with profile errors coming from manufacturing. In a pair of spur gears, one or two pairs of teeth mesh and that's why the spring stiffness of tooth changes, particularly the mesh spring stiffness of a pair of gears with profile errors differs from that of error free gears. Therefore, this paper analyzes the dynamic behavior of a gear system by a transfer matrix method with the mesh spring stiffness which is calculated by means of meshing analysis of a pair of gears with tooth profile errors. Since the tooth profile errors of a pair of gears are represented in terms of composite errors in the plane of action during meshing, composite errors such as pressure angle error type, concave error type, and convex error type are introduced in the analysis. The form of tooth stiffness during a period of mesh is obtained and apply the mean value of tooth stiffness during a period of mesh to analyze the vibration behavior of a geared system. As a result, the tooth profile errors of a pair of gears decrease the value of the mean value of spring stiffness, and this change of the spring stiffness affects not high level natural frequency but the amplitude of a geared system and low level natural frequency.
A Research on Development of Gyro Controller System for the Car Navigation and Black-Box System
Yun, Deuk Seon ; Kim, Jeong Ha ; Kim, Chan Muk ;
Transactions of the Korean Society of Automotive Engineers, volume 7, issue 1, 1999, Pages 295~295
Nowadays, the G.P.S.(Global Positioning System) is generally used for the car navigation system but is has some restrictions such as the discontinuity of earth satellite's signal and the artificial errors which are called S.A.(Selective Availability). To solve these problems, the I.N.S.(Inertial Navigation System) sensor fusioning with G.P.S. is much attractive for improving the accuracy of detecting a vehicle position. The D.R.(Dead Reckoning), which is one of the I.N.S., uses a wheel magnetic sensor for the driving distance and a gyro sensor for the vehicle orientation. The Black-Box, which is the most important record after car accident, contains so much data from acceleration sensors and a gyro sensor. In this paper, Gyro Controller System using one-chip micro processor(i80c196kc) is developed for the D.R. and Black-Box.
Generation of a Double Track Random Road Profile for Vehicle Ride Comfort Simulation
Choe, Gyu Jae ; Yu, Yeong Myeon ; Jo, Yeong Geon ; Lee, Gwang Pyo ; Yun, Yong San ;
Transactions of the Korean Society of Automotive Engineers, volume 7, issue 1, 1999, Pages 305~305
A double track random road profile generation for vehicle ride comfort simulation has been carried out using the filtering method. The filtering method is composed of two filter systems. One is the road filter that generates the single track road PSD shape proposed by ISO, MIRA, and Wong. The other is the correlation filter that makes the relation between the coherence of the parallel tracks of left and right wheel of a vehicle. Generated double track road profiles using the proposed method are in good agreements with the target road PSD shape and the measured coherence relation.
An Algorithm for Design Sensitivity Analysis of General Mechanical Systems
Kim, Dong U ; Yang, Seong Mo ; Kim, Hyeong U ; Bae, Dae Seong ;
Transactions of the Korean Society of Automotive Engineers, volume 7, issue 1, 1999, Pages 312~312
Design sensitivity analysis of a mechanical system is an essential tool for design optimization and trade-off studies. This paper presents an efficient algorithm for the design sensitivity analysis, using the direct differentiation method. The Cartesian coordinate is employed as the generalized coordinate. The governing equations of the design sensitivity analysis are formulated as the differential algebraic equations(DAE). The DAE problem is solved by the local parameterization method. A complicated vehicle system that consists of many different types of joints, bushings, and spring/dampers is analyzed to show the validity and the efficiency of the proposed method.
Vibration of a Vehicle Body Due to Road Roughness
Transactions of the Korean Society of Automotive Engineers, volume 7, issue 1, 1999, Pages 321~321