Go to the main menu
Skip to content
Go to bottom
REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Transactions of the Korean Society of Mechanical Engineers A
Journal Basic Information
Journal DOI :
The Korean Society of Mechanical Engineers
Editor in Chief :
Volume & Issues
Volume 25, Issue 12 - Dec 2001
Volume 25, Issue 11 - Nov 2001
Volume 25, Issue 10 - Oct 2001
Volume 25, Issue 9 - Sep 2001
Volume 25, Issue 8 - Aug 2001
Volume 25, Issue 7 - Jul 2001
Volume 25, Issue 6 - Jun 2001
Volume 25, Issue 5 - May 2001
Volume 25, Issue 4 - Apr 2001
Volume 25, Issue 3 - Mar 2001
Volume 25, Issue 2 - Feb 2001
Volume 25, Issue 1 - Jan 2001
Selecting the target year
Artificial Life Algorithm for Functions Optimization
Yang, Bo-Seok ; Lee, Yun-Hui ; Choe, Byeong-Geun ; Kim, Dong-Jo ;
Transactions of the Korean Society of Mechanical Engineers A, volume 25, issue 2, 2001, Pages 173~181
DOI : 10.22634/KSME-A.2001.25.2.173
This paper presents an artificial life algorithm which is remarkable in the area of engineering for functions optimization. As artificial life organisms have a sensing system, they can find the resource which they want to find and metabolize. And the characteristics of artificial life are emergence and dynamic interaction with environment. In other words, the micro-interaction with each other in the artificial lifes group results in emergent colonization in the whole system. In this paper, therefore, artificial life algorithm by using above characteristics is employed into functions optimization. The optimizing ability and convergent characteristics of this proposed algorithm is verified by using three test functions. The numerical results also show that the proposed algorithm is superior to genetic algorithms and immune algorithms for the multimodal functions.
Improvement of Sensitivity Based Concurrent Subspace Optimization Using Automatic Differentiation
Park, Chang-Gyu ; Lee, Jong-Su ;
Transactions of the Korean Society of Mechanical Engineers A, volume 25, issue 2, 2001, Pages 182~191
DOI : 10.22634/KSME-A.2001.25.2.182
The paper describes the improvement on concurrent subspace optimization(CSSO) via automatic differentiation. CSSO is an efficient strategy to coupled multidisciplinary design optimization(MDO), wherein the original design problem is non-hierarchically decomposed into a set of smaller, more tractable subspaces. Key elements in CSSO are consisted of global sensitivity equation, subspace optimization, optimum sensitivity analysis, and coordination optimization problem that require frequent use of 1st order derivatives to obtain design sensitivity information. The current version of CSSO adopts automatic differentiation scheme to provide a robust sensitivity solution. Automatic differentiation has numerical effectiveness over finite difference schemes tat require the perturbed finite step size in design variable. ADIFOR(Automatic Differentiation In FORtran) is employed to evaluate sensitivities in the present work. The use of exact function derivatives facilitates to enhance the numerical accuracy during the iterative design process. The paper discusses how much the automatic differentiation based approach contributes design performance, compared with traditional all-in-one(non-decomposed) and finite difference based approaches.
Contact Force Estimation of Robot Manipulators in 3-D Space
Lee, Jung-Wook ; Heo, Kun-Soo ;
Transactions of the Korean Society of Mechanical Engineers A, volume 25, issue 2, 2001, Pages 192~197
DOI : 10.22634/KSME-A.2001.25.2.192
Recent requirements for the fast and accurate motion in industrial robot manipulators need more advanced control techniques. To satisfy the requirements, importance of the force control is being continuously increased and the expensive force sensor is often installed to obtain the contact force information in practice. This information is indispensable for the force control of maintaining the desired contact force. However, the sensor cost is too high to be used in industrial applications. In this paper, it is proposed to estimate the contact force occurred between the end-effector of robots and environment in 3-D. The contact force monitoring system is developed based on the static and dynamic models of 3 DOF robot manipulators, where the contact force is described with respect to the link torque. The Extended Kalman Filter is designed and its performance is verified in simulations.
Track Seek Dynamics of HDD Suspension System Considering Air Bearing Effects
Kim, Jeong-Ju ; Park, No-Yeol ; Gang, Tae-Sik ; Jeong, Tae-Geon ;
Transactions of the Korean Society of Mechanical Engineers A, volume 25, issue 2, 2001, Pages 198~205
DOI : 10.22634/KSME-A.2001.25.2.198
Recently, almost all hard disk drives employ the rotary actuator system. The performance of an HDD depends on the accuracy and speed of tracking motion. We study the dynamics of head-suspension assembly during track seek. We develop the numerical analysis program to study the dynamic characteristics of HDD suspension system considering the air bearing effects. The track seek simulation by using the developed program helps to estimate the effect of the suspension vibration on the air bearing dynamics. We calculate the behaviour of the air bearing for the given track seek profile and calculate the positioning error during track seek process due to the lateral deflection of the suspension.
An Experimental Study on the Response Characteristics of Current-Pneumatic Control Valve
Bae, Bong-Guk ; Seok, Chang-Seong ;
Transactions of the Korean Society of Mechanical Engineers A, volume 25, issue 2, 2001, Pages 206~213
DOI : 10.22634/KSME-A.2001.25.2.206
The positioner is an essential component of the control valve which is used to control quantity of the liquid in the pipe of chemical plants. In this paper, the experimental methodology for current pneumatic positioner was developed for the investigation of the static and dynamic characteristics of the positioner. The methodology was applied to evaluate response characteristics of two different positioners, which are current model in market and newly designed model. The experimental results of these two models were compared and analyzed.
The Evaluation of Partially Degraded Material Using Nonlinear Propagation Characteristics of Ultrasonic Wave
Kim, Gyeong-Jo ; Jang, Gyeong-Yeong ; Hisashi, Yamawaki ;
Transactions of the Korean Society of Mechanical Engineers A, volume 25, issue 2, 2001, Pages 214~219
DOI : 10.22634/KSME-A.2001.25.2.214
In this paper, the nonlinear behavior of ultrasonic wave in partially degraded material is considered. For this aim, FDM(finite difference method) model for the nonlinear wave equation was developed with the restriction to the 1-D longitudinal wave motion and how the partial degradation in material contributes to the detected nonlinear parameter was analyzed quantitatively. In order to verify the rightness of this simulation method, the relation between the detected nonlinear parameter and the continuous distribution of degradation obtained from simulation was compared with experiment results and the simulation and experiment results showed similar tendency. It can be known from simulation result that the degree of degradation, the range of degradation and the continuous distribution of degradation have strong correlation with the detected nonlinear parameter. As it was possible in these simulations that only special part is assumed as degraded one, the quantitative evaluation of partially degraded material may be obtained by using this method.
A Study of Fatigue Life Prediction for Automotive Spot Weldment Using Local Strain Approach
Lee, Song-In ; Gwon, Il-Hyeon ; Lee, Beom-Jun ; Yu, Hyo-Seon ;
Transactions of the Korean Society of Mechanical Engineers A, volume 25, issue 2, 2001, Pages 220~227
DOI : 10.22634/KSME-A.2001.25.2.220
The fatigue crack initiation life is studied on automotive tensile-shear spot weldment made from cold rolled carbon steel(SPC) sheet by using DCPDM and local strain approach. It can be found that the fatigue crack initiation behavior in spot weldment can be definitely detected by DCPDM system. To predict the fatigue life of spot weldment, the local stresses and strains at the potential critical region are estimated by approximate method based on Neubers rule and elastic-plastic FEM analysis. A satisfactory correlation between the predicted life obtained from Local strain approach based on Neubers rule and experimental life can be found in spot weldment within a factor of 2.
Simulation of Machined Surface Considering Acceleration Signal in High Speed End Milling
Lee, Gi-Yong ; Gang, Myeong-Chang ; Lee, Deuk-U ; Kim, Jeong-Seok ;
Transactions of the Korean Society of Mechanical Engineers A, volume 25, issue 2, 2001, Pages 228~234
DOI : 10.22634/KSME-A.2001.25.2.228
To obtain precise machined surface and high productivity in machining, high speed end milling has beed studied recently. Though high speed end milling is explicitly effective for precision surface generation geometrically, tool deflection, chatter vibration and frequency characteristics of end milling system deteriorate the theoretical surface. In this study, simulation algorithm and programming method are suggested to simulate machined surface using acceleration signal in high speed end milling. This simulation is conducted by considering vibrational effect of spindle system which was not considered by other investigators. Good agreements were obtained between simulated results and experimental results.
Analysis of a Crack in a Linear Electrostrictive Ceramic Subjected to Electric Fields
Beom, Hyeon-Gyu ; Jeong, Gyeong-Mun ; Gang, Sang-Hyeon ;
Transactions of the Korean Society of Mechanical Engineers A, volume 25, issue 2, 2001, Pages 235~241
DOI : 10.22634/KSME-A.2001.25.2.235
A crack with electrically conducting surfaces in a linear electrostrictive ceramic subjected to uniform electric fields is analyzed. Complete forms of electric fields and elastic fields for the crack are derived by using the complex function theory. The linear electromechanical theory predicts overlapping of the traction free crack surfaces. It is shown that the surfaces of the crack are contact near the crack tip. The contact zone size obtained on the basis of the linear dielectric theory for the conducting crack does not depend on the electric fields and depends on only the original crack and the material property for the linear electrostrictive ceramic.
Synchronous Control of a Two-Axes Driving System by Disturbance Observer
Byeon, Jeong-Hwan ; Yeo, Dong-Jun ;
Transactions of the Korean Society of Mechanical Engineers A, volume 25, issue 2, 2001, Pages 242~249
DOI : 10.22634/KSME-A.2001.25.2.242
In this study, a methodology of synchronous control has been developed that can is applied to position synchronization of a two-axes driving system such as overhead crane. The synchronous error is caused by model uncertainties and torque load at each axis. To overcome these problems, the synchronous control system has been composed of two disturbance observers to calculate the torque disturbance and one synchronous controller to eliminate synchronous error. By considering model uncertainties of each axis, the synchronous controller has been designed using H(sub)
control theory. The effectiveness of the proposed method has been verified through simulation.
A Study on the Design of a High-Speed Heddle Frame
Lee, Chang-Seop ; O, Je-Hun ; Lee, Dae-Gil ;
Transactions of the Korean Society of Mechanical Engineers A, volume 25, issue 2, 2001, Pages 250~263
DOI : 10.22634/KSME-A.2001.25.2.250
The up and down speed of heddle frames that produce woven cloth by insertion of weft yarns between warp yarns has been increased recently much for productivity improvement, which induces higher inertial stresses and vibrations in the heddle frame. the heddle frame is required to reduce its mass because the heddle frame contributes the major portion of the stresses in the heddle frames during accelerating and decelerating. Conventional aluminum heddle frames have fatigue life of around 5 months at 550rpm due to their low fatigue flexural strength as well as low bending stiffness. In this work, since carbon/epoxy composite materials have high specific fatigue strength(S/p), high specific modulus(E/p), high damping capacity and sandwich construction results in lower deflections and higher buckling resistance, the sandwich structure composed of carbon/epoxy composite skins and polyurethane foam were employed for the high-speed heddle frame. The design map for the sandwich beams was accomplished to determine the optimum thickness and the stacking sequences for the heddle frames. Also the effects of the number of ribs on the stress of the heddle frame were investigated by FEM analyses. Finally, the high-speed heddle frames were manufactured with sandwich structures and the static and dynamic properties of the aluminum and the composite heddle frames were tested and compared with each other.
Development of Integrated Fatigue Strength Assessment System
Park, Jun-Hyeop ; Song, Ji-Ho ;
Transactions of the Korean Society of Mechanical Engineers A, volume 25, issue 2, 2001, Pages 264~274
DOI : 10.22634/KSME-A.2001.25.2.264
An integrated fatigue strength assessment system was computerized. The system developed consists of 9 modules: user interface, cycle counting, load history construction, data searching, fatigue properties estimation, fatigue data analysis, true stress and strain analysis, expert system for crack initiation life prediction, fatigue crack initiation and propagation life prediction. Fatigue strength database also was included in this system. The fatigue expert system helps a beginner to predict a fatigue crack initiation life in fatigue strength assessment. The expert system module in this system is developed on the personal computer by using C language and UNiK, an expert system developing tool. To evaluate the system, the results of test under variable loading of SAE and failure data from a field were analyzed. The evaluation show that the system provided fatigue life prediction within 3-scatter band and gave reasonable predictions. To get more accurate predictions of fatigue life without fatigue properties, we recommend utilizing the system along with the fatigue strength database.
Effect of Flaw Characterization on the Structural Integrity Evaluation Under Pressurized Thermal Shock
Kim, Jin-Su ; Choe, Jae-Bung ; Kim, Yeong-Jin ; Park, Yun-Won ;
Transactions of the Korean Society of Mechanical Engineers A, volume 25, issue 2, 2001, Pages 275~282
DOI : 10.22634/KSME-A.2001.25.2.275
The reactor pressure vessel is usually cladded with stainless steel to prevent corrosion and radiation embrittlement. Number of subclad cracks may be found during an in-service-inspection due to the presence of cladding. It is specified, in ASME Sec. XI, that a subclad crack is characterized as a surface crack when the thickness of the clad is less than 40% of the crack depth. This condition is provided to keep the crack integrity evaluation conservative. In order to refine the fracture assessment procedures for such subclad cracks under a pressurized thermal shock condition, three dimensional finite element analyses are applied for various subclad cracks existing under cladding. A total of 36 crack geometries are analyzed, and the results are compared with those for surface cracks. The resulting stress intensity factors for subclad cracks are 6 to 44% less than those for surface cracks. It is proven that the flaw characterization condition as specified in ASME Sec. XI can be overly conservative for some subclad cracks.
A Modeling and Control of Intelligent Cruise Control Systems
Lee, Se-Jin ; Hong, Jin-Ho ; Lee, Gyeong-Su ;
Transactions of the Korean Society of Mechanical Engineers A, volume 25, issue 2, 2001, Pages 283~288
DOI : 10.22634/KSME-A.2001.25.2.283
A throttle/brake control law for the intelligent cruise control(ICC) systems has been proposed in this paper. The ICC system consists of a vehicle detection sensor, the control algorithm and a throttle/brake actuators. For the control of a throttle/brake system, we introduced a solenoid-valve-controlled electronic vacuum booster and a step-motor controlled throttle actuator. Nonlinear computer model for the electronic vacuum booster has been developed and the simulations were per formed using a complete nonlinear vehicle model. The results indicate the proposed throttle/brake control law can provide the ICC system with an optimized performance
Ductile Fracture Behaviour of SPS Specimen Under Pure Mode II Loading
O, Dong-Jun ;
Transactions of the Korean Society of Mechanical Engineers A, volume 25, issue 2, 2001, Pages 289~295
DOI : 10.22634/KSME-A.2001.25.2.289
The aim of this study is to investigate the ductile fracture behaviour under pure Mode II loading using A533B pressure vessel steel. Single punch shear(SPS) test was performed to obtain the J-R curve under pure Mode II loading which was compared with that of the Model I loading. Simulation using Rousellier Ductile Damage Theory(RDDT) was carried out with 4-node quadrilateral element(L(sub)c=0.25mm). For the crack advance, the failed element removal technique was adopted with a
criterion. Through the
value tuning-up procedures,
(sub)crit(sup)II was determined as 1.5 in contrast with
(sub)crit(sup)I=5.5. In conclusion, it was found that the J-R curve under Mode II loading was located at lower part than that under Mode I loading obtained from the previous study and that the
values strongly depended on the loading type. In addition, the predicted result using RDDT showed a good agreement with the SPS experimental one under pure Mode II loading.
Creep Design of Type 316LN Stainless Steel by K-R Damage Theory
Kim, U-Gon ; Kim, Dae-Hwan ; Ryu, U-Seok ;
Transactions of the Korean Society of Mechanical Engineers A, volume 25, issue 2, 2001, Pages 296~303
DOI : 10.22634/KSME-A.2001.25.2.296
Kachanov-Rabotnov(K-R) creep damage theory was reviewed, and applied to design a creep curve for type 316LN stainless steel. Seven coefficients used in the theory, i.e., A, B, k, m, λ, r, and q were determined, and their physical meanings were analyzed clearly. In order to quantify a damage parameter (
), cavity amount was measured in the crept specimen taken from interrupted creep test with time variation, and then the amount was reflected into K-R damage equations. Coefficient λ, which is regarded as a creep tolerance feature of a material, increased with creep strain. Mater curve with λ=2.8 was well coincided with an experimental one to the full lifetime. The relationship between damage parameter and life fraction was matched with the theory at exponent
=24 value. It is concluded that K-R damage equation was reliable as the modelling equation for type 316LN stainless steel. Coefficient data obtained from type 316LN stainless steel can be utilized for life prediction of operating material.
A Study on Stress Distribution Using Boundary Element Analysis Due to Surface Coating in Sliding Contact
Lee, Gang-Yong ; Gang, Jin-U ;
Transactions of the Korean Society of Mechanical Engineers A, volume 25, issue 2, 2001, Pages 304~311
DOI : 10.22634/KSME-A.2001.25.2.304
The present work examines the influence of surface coating on the temperature and the thermo-mechanical stress field produced by friction due to sliding contact. A two-dimensional transient model of a layered medium submitted to a moving heat flux is prsented. A solution technique based on the boundary element method employing the multiregion technique is utilized. Results are presented showing the influence of coating thickness, thermal properties, Peclet number, and mechanical properties. It has been shown that the mechanical properties and thickness of coating have a significant influence on the stress field, even for low temperature increase. The effects of the ratios of shear modulus become more important for low temperature increase than the effects of the ratios of other mechanical properties.
Friction Characteristics of Sheets for The Surface Finish and The Stoning Directions of the Dies
Kim, Dong-Hwan ; Kim, Byeong-Min ; O, Se-Uk ; Park, Chun-Dal ; Hwang, Ji-Seon ;
Transactions of the Korean Society of Mechanical Engineers A, volume 25, issue 2, 2001, Pages 312~322
DOI : 10.22634/KSME-A.2001.25.2.312
This paper investigates the combined effects of parameters such as die surface finish, die directionality of stoning contact pressure and draw speed on the resulting coefficient of friction. Also, this study show the correlation between the NN(Neural Network) and DOE(Design of Experiments) to reduce the number of experiments without the loss of the effects of parameter upon coefficient of friction. The experiments were run in random order with at least three replicates. It was found that the directional stoning orthogonal to the pulling direction is lower friction than directional stoning parallel to the pulling directi on using FCD55 die and SPCEN.
A Study for Color Recognition and Material Delivery of Distributed Multi Vehicles Using Adaptive Fuzzy Controller
Kim, Hun-Mo ;
Transactions of the Korean Society of Mechanical Engineers A, volume 25, issue 2, 2001, Pages 323~329
DOI : 10.22634/KSME-A.2001.25.2.323
In this paper, we present a collaborative method for material delivery using a distributed vehicle agents system. Generally used AGV(Autonomous Guided Vehicle) systems in FA require extraordinary facilities like guidepaths and landmarks and have numerous limitations for application in different environments. Moreover in the case of controlling multi vehicles, the necessity for developing corporation abilities like loading and unloading materials between vehicles including different types is increasing nowadays for automation of material flow. Thus to compensate and improve the functions of AGV, it is important to endow vehicles with the intelligence to recognize environments and goods and to determine the goal point to approach. In this study we propose an interaction method between hetero-type vehicles and adaptive fuzzy logic controllers for sensor-based path planning methods and material identifying methods which recognizes color. For the purpose of carrying materials to the goal, simple color sensor is used instead vision system to search for material and recognize its color in order to determine the goal point to transfer it to. The proposed method reaveals a great deal of improvement on its performance.
Development of Wire Temperature Prediction Method in a Continuous Dry Wire Drawing Process Using the High Carbon Steel
Kim, Yeong-Sik ; Kim, Dong-Hwan ; Kim, Byeong-Min ; Kim, Min-An ; Park, Yong-Min ;
Transactions of the Korean Society of Mechanical Engineers A, volume 25, issue 2, 2001, Pages 330~337
DOI : 10.22634/KSME-A.2001.25.2.330
Wire drawing process of the high carbon steel with a high speed is usually conducted at room temperature using a number of passes or reductions through consequently located dies. In multi-stage drawing process, temperature rise in each pass affects the mechanical properties of final product such as bend, twist and tensile strength. Also, this temperature rise during the deformation is the reason that the wire in drawing process is broken by the embrittlement due to rapid strain aging effect. This paper presents the estimation of the wire temperature for the multi-stage wire drawing process. Using the proposed calculation method of wire temperature, temperature rise at deformation zone as well as temperature drop in block considering the heat transfer between the block and wire were calculated. As these calculated wire temperatures were applied to the real industrial fields, it was known that the calculated results were in a good agreement with the measured wire temperature.