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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Transactions of the Korean Society of Mechanical Engineers A
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Journal DOI :
The Korean Society of Mechanical Engineers
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Volume & Issues
Volume 27, Issue 12 - Dec 2003
Volume 27, Issue 11 - Nov 2003
Volume 27, Issue 10 - Oct 2003
Volume 27, Issue 9 - Sep 2003
Volume 27, Issue 8 - Aug 2003
Volume 27, Issue 7 - Jul 2003
Volume 27, Issue 6 - Jun 2003
Volume 27, Issue 5 - May 2003
Volume 27, Issue 4 - Apr 2003
Volume 27, Issue 3 - Mar 2003
Volume 27, Issue 2 - Feb 2003
Volume 27, Issue 1 - Jan 2003
Selecting the target year
Global Optimization Using Differential Evolution Algorithm
Jung, Jae-Joon ; Lee, Tae-Hee ;
Transactions of the Korean Society of Mechanical Engineers A, volume 27, issue 11, 2003, Pages 1809~1814
DOI : 10.3795/KSME-A.2003.27.11.1809
Differential evolution (DE) algorithm is presented and applied to global optimization in this research. DE suggested initially fur the solution to Chebychev polynomial fitting problem is similar to genetic algorithm(GA) including crossover, mutation and selection process. However, differential evolution algorithm is simpler than GA because it uses a vector concept in populating process. And DE turns out to be converged faster than CA, since it employs the difference information as pseudo-sensitivity In this paper, a trial vector and its control parameters of DE are examined and unconstrained optimization problems of highly nonlinear multimodal functions are demonstrated. To illustrate the efficiency of DE, convergence rates and robustness of global optimization algorithms are compared with those of simple GA.
Influence of Design Parameters on Dynamic Behavior and Frequencies of Cantilever ripe Conveying Fluid
Yoon, Han-Ik ; Son, In-Soo ; Park, Il-Ju ;
Transactions of the Korean Society of Mechanical Engineers A, volume 27, issue 11, 2003, Pages 1815~1823
DOI : 10.3795/KSME-A.2003.27.11.1815
The vibrational system of this study consists of a cantilever pipe conveying fluid, the moving masses upon it and having an attached tip mass. The equation of motion is derived by using Lagrange's equation. The influences of the velocity and the inertia force of the moving mass and the velocities of fluid flow in the pipe have been studied on the dynamic behavior and the natural frequency of a cantilever pipe by numerical method. The deflection of the cantilever pipe conveying fluid is increased due to the tip mass and rotary Inertia. After the moving mass passed upon the cantilever pipe, the amplitude of pipe is influenced by energy variation when the moving mass fall from the cantilever pipe. As the moving mass increase, the frequency of the cantilever pipe conveying fluid is increased. The rotary inertia of the tip mass influences much on the higher frequencies and vibration mode.
The Influence of Tip-mass on Dynamic Characteristics of Rotating Cantilever Pipe Conveying Fluid
Yoon, Han-Ik ; Choi, Chang-Soo ; Son, In-Soo ;
Transactions of the Korean Society of Mechanical Engineers A, volume 27, issue 11, 2003, Pages 1824~1830
DOI : 10.3795/KSME-A.2003.27.11.1824
The vibrational system of this study is consisted of a rotating cantilever pipe conveying fluid and the tip mass. The equation of motion is derived by using the Lagrange equation. The influences of the rotating angular velocity and the velocity of fluid flow in a cantilever pipe have been studied on the dynamic characteristics of a rotating cantilever pipe by the numerical method. The effects of a tip mass on the dynamic response of a cantilever pipe are also studied. The tip-amplitude and maximum tip-deflection of each direction are directly proportional to the tip mass of the cantilever pipe in steady state. It identifies that the influence of the fluid velocity and the rotating angular velocity of the cantilever pipe give much variation the bending tip-displacement of steady state and the bending tip-displacement of non-steady state, respectively. The influence of the rotating angular velocity gives much the deflection of axial direction.
Path following of the passive off-hooked trailer system
Lee, Jae-Hyoung ; Park, Myoung-Kuk ; Chung, Woo-Jin ; Kim, Mun-Sang ; Song, Jae-Bok ;
Transactions of the Korean Society of Mechanical Engineers A, volume 27, issue 11, 2003, Pages 1831~1839
DOI : 10.3795/KSME-A.2003.27.11.1831
This paper deals with design and control of passive multiple trailer systems fer practical applications. Due to cost and complexity of trailer mechanism, passive systems are preferred to active systems in this research. The control objective is to minimize trajectory tracking errors of passive multiple trailers. Three types of passive trailer systems-direct-hooked, three-point, and off-hooked- are discussed in this paper. Trajectory tracking performance and stability issues under constant velocity motion are carried out for three types. Various simulations and experiments have been also performed for these three types. It is shown that the proposed off-hooked trailer system produces better tracking performance than the other types.
Structural Analysis and Optimum Design of a De-coupled Vertical Micro-Gyroscope
Park, Sung-Kyoon ; Jeong, Hee-Moon ; Kim, Myung-Hoon ; Kim, Hyung-Tae ; Ha, Sung-Kyu ;
Transactions of the Korean Society of Mechanical Engineers A, volume 27, issue 11, 2003, Pages 1840~1848
DOI : 10.3795/KSME-A.2003.27.11.1840
This paper presents the structural analysis and optimum design of a vertical micro-gyroscope with decoupled 2 degrees of freedom (DOF), driven by electrostatic force. Simplified beam models were presented to derive the structural stiffness of the driving spring of the U shape and the sensing spring of I shape. A finite element analysis (FEA) was performed to validate each derivation. A total mass and a polar mass moment of inertia were also obtained and used in calculating the resonance frequency at each mode of the 2 DOF. The resonance frequencies of the total system were calculated using the proposed models and it has been found that they were in excellent agreement with those of the FEA. Finally, the developed analysis program was then linked to an optimum design module, and an optimum design of the micro-gyroscope was successfully performed.
Design and fabrication of the Locomotive Mechanism for Capsule Endoscopes Using Shape Memory Alloys (SMA)
Lee, Seung-Hak ; Kim, Byung-Kyu ; Park, Jong-H. ; Park, Jong-Oh ;
Transactions of the Korean Society of Mechanical Engineers A, volume 27, issue 11, 2003, Pages 1849~1855
DOI : 10.3795/KSME-A.2003.27.11.1849
Newly commercialized wireless capsule endoscope has many advantages compared to conventional push-type endoscopes. However, it is moved by the peristaltic waves. Therefore, it can not diagnose desired zones actively. In this paper, a locomotive mechanism for wireless capsule endoscope is proposed to increase the efficiency of endoscopy. We designed and fabricated a prototype using SMA springs and bio-mimetic clamping device. The hollow space in the prototype is allocated for further system integration of a camera module, a RF module and a battery. And the sequential control scheme is employed to improve the efficiency of its locomotion. To validate the performance of the locomotive mechanism, experiments on a silicone rubber pad and in vitro tests are carried out. The results of the experiments indicate that proposed mechanism is effective in harsh environments such as digestive organs of a human.
Description of Hysteresis Loops using Modified Overlay Model
Yoon, Sam-Son ; Hong, Seong-Gu ; Lee, Soon-Bok ;
Transactions of the Korean Society of Mechanical Engineers A, volume 27, issue 11, 2003, Pages 1856~1863
DOI : 10.3795/KSME-A.2003.27.11.1856
Overlay model had several advantages to describe hysteretic behavior of material and showed good capability for many engineering materials. However, this model is only applicable to material obeying Masing postulate. Some materials such as 316L stainless steel do not follow Masing postulate and show cyclic hardening(or softening) and strain range dependence. Low cycle fatigue tests of 316L stainless steel at 600
were performed to investigate the characteristics of cyclic behavior of non-Masing material. From all tests cyclic softening was observed. There were differences in elastic limit of hysteresis loop according to applied strain range. To consider these features, modified overlay model was developed. Yield stresses of subelements were divided into isotropic and anisotropic part to describe the non-Masing behavior. The plastic strain range memorization was introduced to consider the strain range dependence. The prediction using modified overlay model showed a good accordance to actual hysteresis loops.
Pattern Recognition of Rotor Fault Signal Using Bidden Markov Model
Lee, Jong-Min ; Kim, Seung-Jong ; Hwang, Yo-Ha ; Song, Chang-Seop ;
Transactions of the Korean Society of Mechanical Engineers A, volume 27, issue 11, 2003, Pages 1864~1872
DOI : 10.3795/KSME-A.2003.27.11.1864
Hidden Markov Model(HMM) has been widely used in speech recognition, however, its use in machine condition monitoring has been very limited despite its good potential. In this paper, HMM is used to recognize rotor fault pattern. First, we set up rotor kit under unbalance and oil whirl conditions. Time signals of two failure conditions were sampled and translated to auto power spectrums. Using filter bank, feature vectors were calculated from these auto power spectrums. Next, continuous HMM and discrete HMM were trained with scaled forward/backward variables and diagonal covariance matrix. Finally, each HMM was applied to all sampled data to prove fault recognition ability. It was found that HMM has good recognition ability despite of small number of training data set in rotor fault pattern recognition.
A Fundamental Study for the Sliding Wear Characteristics of the Crane Sheave Against a Rope Wire
Ryu, Jung-Buk ; Chae, Young-Hun ; Kim, Seock-Sam ;
Transactions of the Korean Society of Mechanical Engineers A, volume 27, issue 11, 2003, Pages 1873~1880
DOI : 10.3795/KSME-A.2003.27.11.1873
The sliding wear characteristics of the crane sheave were investigated using a pin on disk rig tester. The experiment was conducted using a high carbon steel wire that was upper material, also carbon steel castings that was disk material. There are various operating conditions in this work. At the room temperature, we carried out the wear test under a grease lubrication and dry condition. The results of wear test showed that an annealed-casted have lower, also the wear curves are linearly increased with increasing of sliding distance. For the specific wear rate of annealed-casted, the wear resistance was increased with decreasing diameter of wire. The wear of a wire and a disk have a different mechanism, the one is the abrasive wear due to fatigue wear under lubrication, another is the adhesion wear under dry condition.
A Study on Roll Wear in the Roll Forming Process
Kang, Byung-Seok ; Kim, Nak-Soo ;
Transactions of the Korean Society of Mechanical Engineers A, volume 27, issue 11, 2003, Pages 1881~1888
DOI : 10.3795/KSME-A.2003.27.11.1881
This study show a numerical method to predict roll wear in the roll forming process. Archard's wear model was reformulated in an elemental form to predict volume of roll wear and then wear depth on the roll was calculated using the results of finite element analysis. Abrasive wear occurs at contact area in the roll forming process and the results of simulation are compared with experimental data in production line. The wear simulation approach with 3-D FEM program for roll forming process, SHAPE-RF is in good agreement with it in tendency.
Optimum Design of a Viscous-driven Micropump with Single Rotating Cylinder for Maximizing Efficiency
Choi, Hyung-Il ; Kim, Jong-Min ; Choi, Dong-Hoon ; Maeng, Joo-Sung ;
Transactions of the Korean Society of Mechanical Engineers A, volume 27, issue 11, 2003, Pages 1889~1896
DOI : 10.3795/KSME-A.2003.27.11.1889
In the microfluidic applications, viscous-driven pumping mechanism is a promising one since the viscous effect increases significantly as the size of device decreases, relative to the inertial effect. However, there exist a few drawbacks we have to improve such as low efficiency and small volume flow rate. In the present study, an optimum design synthesis is proposed to enhance the performance characteristics of the micropump with single rotating cylinder. First, the unstructured grid CFD method is described and validated by comparing its results to the previous results. Next, an automated optimum design synthesis tool is constructed by combining the aforementioned CFD analysis model with the mathematical optimization model. This technique is used to improve the performance characteristics of newly designed viscous-driven pump. The presented results show that the fluid dynamic optimization tool is robust and may be applied to other microfluidic device design applications.
A Finite Element Analysis for Near-net-shape Forming of A16061 Powder under Warm Pressing
Kim, Jong-Kwang ; Yang, Hoon-Chul ; Kim, Ki-Tae ;
Transactions of the Korean Society of Mechanical Engineers A, volume 27, issue 11, 2003, Pages 1897~1906
DOI : 10.3795/KSME-A.2003.27.11.1897
A finite element analysis for near-net-shape forming of A16061 powder was performed under warm rubber isostatic pressing and warm die pressing. The advantages of warm compaction by rubber isostatic pressing were discussed to obtain a part with better density distributions. The shape of rubber mold was designed by determining a cavity shape that provides a desired shape of the final powder compact. To simulate densification and deformed shape of a powder compact during pressing, the elastoplastic constitutive equation based on yield function of Shima-Oyane was implemented into a finite element program(ABAQUS). The hyperelastic constitutive equation based on the Ogden strain energy Potential was employed to analyze nonlinear elastic response of rubber. Finite element results were compared with experimental data for Al6061 powder compacts under warm die pressing and warm isostatic pressing.
Comparison of Semi-Implicit Integration Schemes for Rate-Dependent Plasticity
Yoon, Sam-Son ; Lee, Soon-Bok ;
Transactions of the Korean Society of Mechanical Engineers A, volume 27, issue 11, 2003, Pages 1907~1916
DOI : 10.3795/KSME-A.2003.27.11.1907
During decades, there has been much progress in understanding of the inelastic behavior of the materials and numerous inelastic constitutive equations have been developed. The complexity of these constitutive equations generally requires a stable and accurate numerical method. To obtain the increment of state variable, its evolution laws are linearized by several approximation methods, such as general midpoint rule(GMR) or general trapezoidal rule(GTR). In this investigation, semi-implicit integration schemes using GTR and GMR were developed and implemented into ABAQUS by means of UMAT subroutine. The comparison of integration schemes was conducted on the simple tension case, and simple shear case and nonproportional loading case. The fully implicit integration(FI) was the most stable but amplified the truncation error when the nonlinearity of state variable is strong. The semi-implicit integration using GTR gave the most accurate results at tension and shear problem. The numerical solutions with refined time increment were always placed between results of GTR and those of FI. GTR integration with adjusting midpoint parameter can be recommended as the best integration method for viscoplastic equation considering nonlinear kinematic hardening.
A Study on Efficient Roughing of Impeller with 5-Axis NC Machine
Cho, Hwan-Young ; Jang, Dong-Kyu ; Lee, Hi-Koan ; Yang, Gyun-Eui ;
Transactions of the Korean Society of Mechanical Engineers A, volume 27, issue 11, 2003, Pages 1917~1924
DOI : 10.3795/KSME-A.2003.27.11.1917
This paper proposes a roughing path generation method fer machining impeller with 5-axis machining center. Traditional researches are focus on finishing for machining impeller. To achieve efficient machining, roughing method must be studied. The proposed method consists two steps : One is to select optimal tool size and tool attitude by dividing cutting area into two regions to reduce cutting time. The regions are automatically divided by character point on the geometry of impeller blade. After dividing, the tool of the optimal size is selected for each divided region. The other is avoidance of tool interference. Tool interference in cutting areas is avoided by checking the distance between tool axis vector and ruling line on blade surface or approximated plan between ruling line. Using this method, the cutting time is reduced efficiently.
CAD Model Construction Using Topology Image
Lee, Dong-Hoon ; Min, Seung-Jae ;
Transactions of the Korean Society of Mechanical Engineers A, volume 27, issue 11, 2003, Pages 1925~1932
DOI : 10.3795/KSME-A.2003.27.11.1925
Topology optimization is widely accepted as a conceptual design tool for the product design. Since the resulted layout of the topology optimization is a kind of digital images represented by the density distribution, the seamless process is required to transform digital images to the CAD model for the practical use. In this paper, the general process to construct a CAD model is developed to apply for topology images based on elements. The node density and the morphology technique are adopted to extract boundary contour of the shape and remove the noise of images through erosion and dilation operation. The proposed method automatically generates point data sets of the geometric model. The process is integrated with Pro/Engineer, so that the engineer in practice can directly handle with curves or surfaces form digital images.
Development of a Knowledge-Based Information Management System for Plant Maintenance
Park, Young-Jae ; Lee, Sang-Min ; Yim, Hyung-Sang ; Choi, Jae-Boong ; Kim, Young-Jin ; Roh, Eun-Chul ; Lee, Byung-Ine ;
Transactions of the Korean Society of Mechanical Engineers A, volume 27, issue 11, 2003, Pages 1933~1940
DOI : 10.3795/KSME-A.2003.27.11.1933
Recently, the importance of plant maintenance(PM) was highly raised to provide efficient plant operation which highly affects the productivity. For this reason, a number of engineering methodologies, such as risk-based inspection(RBI), fitness for service guidelines(FFS), plant lifecycle management(PLM), have been applied to improve the plant operation efficiency. Also, a network-based business operation system, which is called ERP(Enterprise Resource Planning), has been introduced in the field of plant maintenance. However, there was no attempt to connect engineering methodologies to the ERP PM system. In this paper, a knowledge-based information system for the plant operation of steel making company has been proposed. This system which is named as K-VRS(Knowledge-based Virtual Reality System), provides a connection between ERP plant maintenance module and knowledge-based engineering methodologies, and thus, enables network-based highly effective plant maintenance process. The developed system is expected to play a great role for more efficient and safer plant maintenance.
Feasibility Study of Positioning Device Using Magnetic Suspension System of Out of Plane Direction Forces
Lee, Sang-Heon ; Baek, Yoon-Su ;
Transactions of the Korean Society of Mechanical Engineers A, volume 27, issue 11, 2003, Pages 1941~1948
DOI : 10.3795/KSME-A.2003.27.11.1941
This paper is about feasibility study of positioning device using magnetic suspension system which uses only vertical magnetic forces. The proposed system has inherited advantages from contact-free system, simple structure, and high expansibility in operating range different from conventional positioning devices. In this paper, the structure and operating principle are described and the linearized magnetic force and dynamic model are obtained. With the linear control theory, the experiments are executed. finally, the experimental results are shown.
Influence of Ring Gear Boundary Conditions on the Static Characteristics of Epicyclic Gear Trains with Manufacturing Errors
Cheon, Gill-Jeong ;
Transactions of the Korean Society of Mechanical Engineers A, volume 27, issue 11, 2003, Pages 1949~1957
DOI : 10.3795/KSME-A.2003.27.11.1949
A hybrid finite element analysis was used to analyze the influence of ring gear rim thickness and spline number on the static properties of a planetary gear system with manufacturing errors. Both of these parameters affected the bearing force and critical stress. The effect of changes in the rim thickness on the load sharing between the gears depended on the type of manufacturing error. Ring flexibility improved the load sharing between planetary gears only in systems with planet tooth thickness or planet tangential errors; for other types of error, ring flexibility worsened the load sharing. To improve load sharing, rim thickness and spline number should be controlled within a specific range. The minimum rim thickness limit should be determined considering not only the critical stress but also the load sharing. The effect of the ring gear boundary condition was more apparent in a system with errors than in a normal system.
Integrated NURBS Surface Interpolator Considering Both Rough and Finish Cuts
Koo, Tae-Hoon ; Jee, Sung-Chul ;
Transactions of the Korean Society of Mechanical Engineers A, volume 27, issue 11, 2003, Pages 1958~1966
DOI : 10.3795/KSME-A.2003.27.11.1958
Three-axis CNC surface machining entails a series of processes including rough cutting, intermediate cutting and finish cutting for a reference surface defined in CAD/CAM. This study is targeting development of an integrated NURBS surface interpolator that can incorporate rough, intermediate and finish cutting processes. In each process, volume to be removed and cutting condition are different according to the shape of a part to be machined and the reference surface. Accordingly, the proposed NURBS surface interpolator controls motion in real-time optimized for the machining conditions of each process. In this paper, a newly defined set of G-codes is proposed such that NURBS surface machining through CNC is feasible with minimal information on the surface composition. To verify the usefulness of the proposed interpolator, through computer simulations on NURBS surface machining, total machining time, size of required NC data and cutting force variations are compared with the existing method.
Transparency Implementation for Bilateral Teleoperation System by using Two-channel Control Architecture
Kim, Jong-Hyun ; Chang, Pyung-Hun ; Park, Hyung-Soon ;
Transactions of the Korean Society of Mechanical Engineers A, volume 27, issue 11, 2003, Pages 1967~1978
DOI : 10.3795/KSME-A.2003.27.11.1967
Transparency has been considered as a performance measure in bilateral teleoperation system. Therefore, many issues of transparency have been studied. This paper investigates the transparency in two-channel control architectures. At first, we show the feasibility using analytic transparency-conditions and present the two classes of two-channel control architecture, which are perfectly transparent under ideal situation. In addition, remedies to problems due to impedance model estimation errors under real situation are introduced. They are as fellows; design guideline of control parameters to reduce the effect of model estimation error effect and introduction of time delay estimation for unknown dynamics. From these analyses, the systematic control scheme, which is stable and well transparent under real implementation, is proposed in two-channel control architecture. Finally, the proposed scheme is applied to a 2 D.O.F master-slave system and the experimental results show the validity of the theoretical work.
The Effect of Degradation on the Fretting fatigue for 1Cr-0.5Mo Steel
Kwon, Jae-Do ; Choi, Sung-Jong ; Kim, Kyung-Soo ; Bae, Yong-Tak ;
Transactions of the Korean Society of Mechanical Engineers A, volume 27, issue 11, 2003, Pages 1979~1985
DOI : 10.3795/KSME-A.2003.27.11.1979
Fretting is a kind of surface degradation mechanism observed in mechanical components and structures. The fretting damage decreases in 50-70% of the plain fatigue strength. This may be observed in the fossil power plant and the nuclear power plant used in special environments and various loading conditions. The thermal degradation of material is observed when the heat resisting steel is exposed for long period time at the high temperature. In the present study, the degraded 1Cr-0.5Mo steel used for long period time at high temperature (about 515
) and artificially reheat-treated materials are prepared. These materials are used for evaluating an effect of thermal aging on the fretting fatigue behavior. Through the experiment, it is found that the fretting fatigue endurance limit of the reheat-treated 1Cr-0.5Mo steel decreased about 46% from the non-fretting fatigue endurance limit, while the fretting fatigue endurance limit of the degraded 1Cr-0.5Mo steel decreased about 53% from the non-fretting fatigue endurance limit. The maximum value of fatigue endurance limit difference is observed as 57%(244 MPa) between the fretting fatigue of degraded material and non-fretting fatigue of reheat-treated material. These results can be a basic data to a structural integrity evaluation of heat resisting steel considered to thermal degradation effect.
A Study on Accuracy of J-Resistance Curves Measured with Curved Compact Tension Specimen of Zr-2.5Nb Pressure Tube
Yoon, Kee-Bong ; Park, Tae-Gyu ; Kim, Young-Suk ;
Transactions of the Korean Society of Mechanical Engineers A, volume 27, issue 11, 2003, Pages 1986~1996
DOI : 10.3795/KSME-A.2003.27.11.1986
Methodology based on the elastic-plastic fracture mechanics has been widely accepted in predicting the critical crack length(CCL) of pressure tubes of CANDU nuclear plants. A conservative estimate of CCL is obtained by employing the J-resistance curves measured with the specimens satisfying plane strain condition as suggested in the ASTM standard. Due to limited thickness of the pressure tubes the curved compact tension(CT) specimens taken out from tile pressure tube have been used in obtaining J-resistance curves. The curved CT specimen inevitably introduce slant fatigue crack during precracking. Hence, effect of specimen geometry and slant crack on J-resistance curve should be explored. In this study, the difference of J integral values between the standard CT specimens satisfying plane strain condition and the nonstandard curved CT with limited thickness (4.2mm) is estimated using finite element analysis. The fracture resistance curves of Zr-2.5Nb obtained previously by other authors are critically discussed. Various finite element analysis were conducted such as 2D analysis under plane stress and plane strain conditions and 3D analysis for flat CT, curved CT with straight crack and curved CT with slant crack front. J-integral values were determined by local contour integration near the crack tip, which was considered as accurate J-values. J value was also determined from the load versus load line displacement curve and the J estimation equation in the ASTM standard. Discrepancies between the two values were shown and suggestion was made for obtaining accurate J values from the load line displacement curves obtained by the curved CT specimens.