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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
Journal Basic Information
Journal DOI :
The Korean Society of Mechanical Engineers
Editor in Chief :
Volume & Issues
Volume 34, Issue 12 - Dec 2010
Volume 34, Issue 11 - Nov 2010
Volume 34, Issue 10 - Oct 2010
Volume 34, Issue 9 - Sep 2010
Volume 34, Issue 8 - Aug 2010
Volume 34, Issue 7 - Jul 2010
Volume 34, Issue 6 - Jun 2010
Volume 34, Issue 5 - May 2010
Volume 34, Issue 4 - Apr 2010
Volume 34, Issue 3 - Mar 2010
Volume 34, Issue 2 - Feb 2010
Volume 34, Issue 1 - Jan 2010
Selecting the target year
Design of Fastener for Solid Rocket Motor Using Solid CAD System
Lee, Kang-Soo ; Kim, Won-Hoon ; Seok, Jung-Ho ;
Transactions of the Korean Society of Mechanical Engineers A, volume 34, issue 7, 2010, Pages 805~811
DOI : 10.3795/KSME-A.2010.34.7.805
When we design a product, we spend a considerable amount of time in designing fasteners and their mating parts. Fasteners have special features because of which they are widely used and well standardized. Although we use some equations to design the fasteners, we should select these fasteners from the standardized table. In order to design them quickly using the CAD system, we proceeded as follows. First, we prepared some standardized shapes of fasteners to design them automatically. Next, we built a database of some fasteners such as a tension bolt, lock wire, thread, pin, and snap ring. Then, we used the design equations to quickly and precisely calculate the various parameters. Finally, we used a configuration design method to generate the shapes automatically using the results of the calculation and the values retrieved from the database. We applied this approach to the design of a propulsion structure, and demonstrated that this approach worked well and saved considerable time.
Optimization of Vertical Roller Mill by Using Artificial Neural Networks
Lee, Dong-Woo ; Cho, Seok-Swoo ;
Transactions of the Korean Society of Mechanical Engineers A, volume 34, issue 7, 2010, Pages 813~820
DOI : 10.3795/KSME-A.2010.34.7.813
The vertical roller mill is important for machine grinding and mixing various crude materials in the process of producing Portland cement. A vertical roller mill is subjected to cyclic bending stress because of the roller load. Because of the cyclic bending stress, only
cycles are achieved instead of
cycles. The stress also causes fractures at the edge of grinding path of the outer roller. The expenses incurred in repairing the grinding path amounts to 30% of the total maintenance cost. Therefore, it is desirable to redesign the vertical roller mill in order to reduce the expenses incurred in repairing the roller. In this study, artificial neural networks (ANNs) were applied in order to solve the multiobjective optimization problem for vertical roller mills by using the function approximation ability of ANNs. To learn and generalize ANNs, the maximum and minimum stresses were estimated from the results of the finite-element analysis of a vertical roller mill. Thus, ANNs could be applied to solve the multiobjective optimization problem.
Topology Optimization of Perpendicular Magnetic Recording System by Considering Magnetic Nonlinearity
Park, Soon-Ok ; Yoo, Jeong-Hoon ; Min, Seung-Jae ;
Transactions of the Korean Society of Mechanical Engineers A, volume 34, issue 7, 2010, Pages 821~827
DOI : 10.3795/KSME-A.2010.34.7.821
This paper proposes a density method based topology optimization of a perpendicular magnetic recording system design in which the saturation effect is taken into account. During the topology optimization process in magnetic fields, the magnetic reluctivity is updated in accordance with the changes in element density determined by a sensitivity analysis. The magnetic reluctivity is determined from a B-H curve and is used to represent nonlinear material property, i.e., the saturation effect. The sensitivity for a generalized response functional is formulated using the adjoint variable method in which the nonlinear property is taken into account and the objective function is set such that the magnetic energy in the media is maximized. Effects due to the nonlinear property can be observed from a numerical study in which the linear and the nonlinear topology optimization results are compared.
Disposable Power Generator with Tubular PEMFC and H
Generator for the Power Source of Microfluidic Devices
Kim, Kwang-Ho ; Seo, Young-Ho ; Kim, Byeong-Hee ;
Transactions of the Korean Society of Mechanical Engineers A, volume 34, issue 7, 2010, Pages 829~835
DOI : 10.3795/KSME-A.2010.34.7.829
This paper presents a disposable power generator for microfluidic devices; the power generator has a tubular PEMFC and a
generator. The tubular PEMFC has a tubular MEA (diameter: 1.52 mm) that is supported by a spiral wire electrode. The
to the tubular PEMFC;
was generated via the reaction of Al foil (27 mg) and 5 M NaOH (0.12 ml). The open circuit voltage and power density of a unit cell of the tubular PEMFC were 0.81 V and
(0.35 V), respectively. The
generator generated 11.6 ml
for 15min. The power generator was continuously operated for 15 min at 0.64 mW (0.71 V) and for 10 min at 1.06 mW (0.46 V). We experimentally verified that it is feasible to use the proposed power generator as a power source for microfluidic devices; in the experiment, an LED (2.5 mW; 1.8 V) was lit for 10 min by using three serially connected TPEMFCs and one
Estimation of Contact Pressure of a Flat Wiper Blade by Dynamic Analysis
Kim, Wook-Hyeon ; Park, Tae-Won ; Chai, Jang-Bom ; Jung, Sung-Pil ; Chung, Won-Sun ;
Transactions of the Korean Society of Mechanical Engineers A, volume 34, issue 7, 2010, Pages 837~842
DOI : 10.3795/KSME-A.2010.34.7.837
The wiper system of a vehicle is important because it wipes the windshield, thereby enabling drivers to see through the windshield even under conditions of rain and snow. The blade is the key component of the wiper system because it wipes the windshield. When wiper-arm spring causes the blade to be pressed on the windshield optimum performance of wiping can be achieved when appropriate contact pressure is maintained. In this study, a dynamic analysis of the wiper system is carried out. A three-dimensional finite-element model of the wiper system is generated using SAMCEF, a commercial structural dynamic analysis program. The distribution of the contact pressure of the blade in its dynamic state is calculated. The simulation result is compared to the experiment result. Using the results of this study, the contact pressure of the blade can be estimated.
Spacer Grid Assembly with Sliding Fuel Rod Support
Song, Kee-Nam ; Lee, Sang-Hoon ;
Transactions of the Korean Society of Mechanical Engineers A, volume 34, issue 7, 2010, Pages 843~850
DOI : 10.3795/KSME-A.2010.34.7.843
A spacer grid assembly is one of the most important structural components of the nuclear fuel assembly of a Pressurized Water Reactor (PWR). A primary design requirement is that the fuel rod integrity be maintained by the spacer grid assembly during the operation of the reactor. In this study, we suggested a new spacer grid assembly having a fuel rod support, which is capable of sliding when the fuel rod vibrates due to flow-induced vibrations in the reactor. By adjusting the relative displacement between the fuel rod and its support, the proposed design will help in reducing fuel rod fretting damage.
Transient Elastodynamic Mode III Crack Growth in Functionally Graded Materials
Lee, Kwang-Ho ;
Transactions of the Korean Society of Mechanical Engineers A, volume 34, issue 7, 2010, Pages 851~858
DOI : 10.3795/KSME-A.2010.34.7.851
A generalized elastic solution for a transient mode III crack propagating along the gradient in functionally graded materials (FGMs) is obtained through an asymptotic analysis. The shear modulus and density of the FGMs are assumed to vary exponentially along the gradient. The stress and displacement fields near the crack tip are obtained in terms of powers of radial coordinates, and the coefficients depend on the time rates of the change of the crack tip speed and stress intensity factors. The influence of nonhomogeneity and transients on the higher order terms of the stress and displacement fields is discussed.
Replication of Multi-level Microstructures by Microinjection Molding Using Modularized and Sectioned Micromold System
Lee, Bong-Kee ; Kwon, Tai-Hun ;
Transactions of the Korean Society of Mechanical Engineers A, volume 34, issue 7, 2010, Pages 859~866
DOI : 10.3795/KSME-A.2010.34.7.859
In this study, microinjection molding process using the newly developed micromold system, namely modularized and sectioned micromold system (MSMS), has been carried out for a replication of multi-level microstructures. The present MSMS consisted of several micromold modules, each having cross-sectional microstructures on the top surface. The micromold modules were precisely fabricated by deep X-ray lithography and subsequent nickel electroforming. By assembling the micromold modules, an MSMS having multi-level microstructures, which could be used as a mold system in micromolding processes, was obtained. In this manner, polymeric multi-level microstructures, such as the triangular prism microstructures on a stepped surface, were successfully replicated by the microinjection molding process.
Design of a Piezocomposite Generating Element and Its Characteristics
Tien, Minh Tri ; Kim, Jong-Hwa ; Goo, Nam-Seo ;
Transactions of the Korean Society of Mechanical Engineers A, volume 34, issue 7, 2010, Pages 867~872
DOI : 10.3795/KSME-A.2010.34.7.867
Unused energy derived from sources in nature can be captured and stored for future use, for example, to recharge a battery or power a device; this process of capturing and storing energy is called energy harvesting. Extensive investigations are being carried out in order to use piezoelectricity to harvest the energy generated by body movements or machine vibrations. This paper presents a simple analytical model that describes the output voltage effectiveness of a Piezocomposite Generating Element (PCGE) from vibration and its experimental verification. PCGE is composed of carbon/epoxy, PZT, and glass/epoxy layers. During the manufacturing process, the stacked layers were cured at
in an autoclave, which created residual stresses in PCGE and altered the piezoelectric properties of the PZT layer. In the experiments, three kinds of lay-up configurations of PCGE were considered to verify the proposed prediction model and to investigate its capability to convert oscillatory mechanical energy into electrical energy. The predicted performance results are in good agreement with observed experimental ones.
Prediction of Changed Design Parameter of Proportional Damping Structure by Using Modified Dynamic Characteristics
Lee, Jung-Youn ;
Transactions of the Korean Society of Mechanical Engineers A, volume 34, issue 7, 2010, Pages 873~879
DOI : 10.3795/KSME-A.2010.34.7.873
It is common to predict structural dynamic design parameters due to the change of design parameter, but to predict the amount of changed design parameter where the mass and stiffness are being modified are rarely found in previous literature. In this study, the changed design parameter in a proportional damping system is predicted by using sensitivity coefficients and an iterative method. The sensitivity coefficients are determined from the changes in eigenvectors; these changes are due to modification. This method is applied to a three-story shear structure. To validate the prediction of the changed design parameter, the results are compared to the reanalysis results; both results are in good agreement.
Volume Integral Equation Method for Multiple Isotropic Inclusion Problems in an Infinite Solid Under Uniaxial Tension
Lee, Jung-Ki ;
Transactions of the Korean Society of Mechanical Engineers A, volume 34, issue 7, 2010, Pages 881~889
DOI : 10.3795/KSME-A.2010.34.7.881
A volume integral equation method (VIEM) is introduced for solving the elastostatic problems related to an unbounded isotropic elastic solid; this solid is subjected to remote uniaxial tension, and it contains multiple interacting isotropic inclusions. The method is applied to two-dimensional problems involving long parallel cylindrical inclusions. A detailed analysis of the stress field at the interface between the matrix and the central inclusion is carried out; square and hexagonal packing of the inclusions are considered. The effects of the number of isotropic inclusions and different fiber volume fractions on the stress field at the interface between the matrix and the central inclusion are also investigated in detail. The accuracy and efficiency of the method are clarified by comparing the results obtained by analytical and finite element methods. The VIEM is shown to be very accurate and effective for investigating the local stresses in composites containing isotropic fibers.
Design and Analysis of Gerotor with Generalized Shapes for Power-Steering Units
Jeong, Jae-Tack ; Shin, Soo-Sik ; Kim, Kap-Tae ;
Transactions of the Korean Society of Mechanical Engineers A, volume 34, issue 7, 2010, Pages 891~896
DOI : 10.3795/KSME-A.2010.34.7.891
A gerotor is used in power-steering units (PSUs) as well as in hydraulic motors or pumps. The inner rotor is developed on the basis of the shape of the outer rotor tooth, which normally has one arc. The method of generating inner rotor on the basis of a generalized shape of outer rotor is analyzed with a view to improve PSU characteristics. An arc-shaped outer rotor with two curvatures was used in the analysis; design parameters such as the shape and curvature of the inner rotor, the flow rate of the gerotor, the position of contact point, and slip velocity are calculated, and these results are shown. This analysis enables us to develop a new design of compact PSUs.
Optimization of Explosion Prevention for LPG Storage Tanks
Leem, Sa-Hwan ; Huh, Yong-Jeong ; Son, Seok-Woo ; Lim, Jae-Ki ; Lee, Jong-Rark ;
Transactions of the Korean Society of Mechanical Engineers A, volume 34, issue 7, 2010, Pages 897~903
DOI : 10.3795/KSME-A.2010.34.7.897
Used gas to the vehicle fuel are the problems of the 'survival' beyond the 'quality of life' improvements and revive a new paradigm of 'sustainable development' which pursues economic development in harmony with environmental conservation. However, the fatalities caused by explosions and fires increases every year with the increase in the use of LPG; gas accidents in large-scale storage facilities also cause severe damage to property. In this study, a suitable storage tank is designed in which the surface area of the fuel exposed to flames is minimized in order to prevent explosions; thus, the occurrences of explosions in underground storage tanks can be minimized. According to the optimum design of storage tank obtained in this study, underground containment space was minimized; the minimized diameter and length of a 20-ton storage tank was 3 m and 4.83 m, respectively. Thus, safety was ensured since surface area exposed to flames decreased by 89.4%, which is less than the exposed surface area in the currently used storage tanks.
Design and Performance Evaluation of Integrated Exhaust Manifold
Oh, Jin-Ho ; Ryu, Jeong-Soo ; Kim, Jae-Hyun ; Choi, Han-Ho ;
Transactions of the Korean Society of Mechanical Engineers A, volume 34, issue 7, 2010, Pages 905~910
DOI : 10.3795/KSME-A.2010.34.7.905
Exhaust manifolds are the first structures to be developed by hydroforming; mass production of exhaust manifolds by this method will be possible soon. This is obviously related with tight emission regulation induced by environmental problems commonly for both domestic and worldwide and standards, thus evoking its solution for domestic automakers. Compared to conventional cast products, thin-gauge tubular hydroformed exhaust manifold have superior features; for example, in the hydroformed exhaust manifold, gas decomposition during the cold-start period of the engine is reduced by lowering the heat sink, and manufacturing process is simplified since less welding is involved. The aim of this study is to develop a hydroformed exhaust manifold; the study deals with the components, the hydroforming process, and tool design of the manifolds. The performance of the exhaust system is evaluated by performing flow analysis, heat-transfer analysis, heat-stress analysis, and fatigue analysis by using a computer.
Prediction of Thermal Fatigue Life of Engine Exhaust Manifold under Thermo-mechanical Cyclic Loading
Choi, Bok-Lok ; Chang, Hoon ;
Transactions of the Korean Society of Mechanical Engineers A, volume 34, issue 7, 2010, Pages 911~917
DOI : 10.3795/KSME-A.2010.34.7.911
In this study, we performed structural and fatigue analyses of the engine exhaust manifold that was subjected to thermo-mechanical cyclic loading. The methodologies used in this study are based on an approach in which the techniques for modeling the exhaust system, the temperature-dependent properties of the material, and thermal cyclic loading are taken into consideration and a reliable strategy is adopted for failure prediction. An application example shows that at an elevated temperature, considerable compressive plastic deformation is observed and that at a low temperature, tensile stresses remain in those parts of the test exhaust manifold where failure is observed. In order to predict fatigue life, mechanical damage is determined on the basis of the stress.strain hysteresis loops by using the classical Coffin.Manson equation and by adopting a method in which the dissipated plastic energy is taken into consideration.
Development of High-Speed Width-Changing Pattern in Continuous Caster
Kang, Gi-Pan ; Shin, Geon ; Kang, Chung-Gil ;
Transactions of the Korean Society of Mechanical Engineers A, volume 34, issue 7, 2010, Pages 919~928
DOI : 10.3795/KSME-A.2010.34.7.919
Four patterns for width adjustment were studied with an aim to increase the width-adjustment speed in continuous casting. The main goals are to minimize the actuating force of a WAM actuator, to develop a deformation analysis model of a solidified shell in the mold, and to induce the main limit factor for the speedup of width adjustment. On the basis of the width-adjustment experiment, the notable features of four patterns types were considered, and we compared the corresponding actuating forces. For comparing the driving forces of the patterns, during the experiment, the same casting speed was maintained for each pattern. To optimize the parameter of the deformation analysis model of the solidified shell, the experiment results were applied to them. To speed up width adjustment and to reduce the driving force, we controlled the pattern parameters. The most effective pattern was the fast-mode pattern, and the taper was the main parameter that helped reduce the driving forces during the motion of the actuator.
Characterization of Interfacial Adhesion of Cu-Cu Bonding Fabricated by Thermo-Compression Bonding Process
Kim, Kwang-Seop ; Lee, Hee-Jung ; Kim, Hee-Yeoun ; Kim, Jae-Hyun ; Hyun, Seung-Min ; Lee, Hak-Joo ;
Transactions of the Korean Society of Mechanical Engineers A, volume 34, issue 7, 2010, Pages 929~933
DOI : 10.3795/KSME-A.2010.34.7.929
Four-point bending tests were performed to investigate the interfacial adhesion of Cu-Cu bonding fabricated by thermo-compression process for three dimensional packaging. A pair of Cu-coated Si wafers was bonded under a pressure of 15 kN at
for 1 h, followed by post annealing at
for 1 h. The bonded wafers were diced into
pieces for the test. Each specimen had a
-deep notch along the center. An optical inspection module was installed in the testing apparatus to observe crack initiation at the notch and crack propagation over the weak interface. The tests were performed under a fixed loading speed, and the corresponding load was measured. The measured interfacial adhesion energy of the Cu-to-Cu bonding was
, and the delaminated interfaces were analyzed after the test. The surface analysis shows that the delamination occurred in the interface between
Vibration Analysis of a Cooling Fan Gear Reducer of the Secondary Cooling Tower in HANARO
Park, Young-Chul ;
Transactions of the Korean Society of Mechanical Engineers A, volume 34, issue 7, 2010, Pages 935~941
DOI : 10.3795/KSME-A.2010.34.7.935
HANARO is an open-tank-in-pool-type Korean research reactor that generates 30MW of thermal power. It differs from power plant reactor in that the heat generated by HANARO is exhausted into the atmosphere through a secondary cooling tower, thus maintaining the core temperature constant. During every monthly inspection of the cooling tower, large vibrations that exceeded the permissible limit were observed at cooling fan gear reducer No. 4 of the cooling tower. The purpose of this study is to identify the origin of the large vibration and to repair it. FFT spectrum analysis is performed to identify the part that caused the large vibration. The results of the frequency analysis showed that the vibration frequency was 354 Hz, which is twice the natural frequency of the pinion gear. A check of the pinion gear revealed that there was a crack on the surface of the pinion gear. After the gear was replaced, the reducer operated normally.
Evaluation of Shock-Absorbing Performance of Three-Different Types of Bicycle Suspension Systems
Chung, Kyung-Ryul ; Hyeong, Joon-Ho ; Kim, Sa-Yup ;
Transactions of the Korean Society of Mechanical Engineers A, volume 34, issue 7, 2010, Pages 943~946
DOI : 10.3795/KSME-A.2010.34.7.943
In this study, a front suspension system, which is mounted on the handle itself, was suggested because of its light weight and cost efficiency. The shock absorption was evaluated for the three types of suspension models; non-suspension, suspension on front forks (existing model), and suspension on handle (suggested model). The human body model was used for performing impact simulation for comparing the shock absorption for the suspension models. The result of the simulation shows that shock absorption for the proposed suspension model was not as good as that for the front fork suspension model. Nevertheless, the shock absorption observed for the proposed suspension model was significant when compared to the non-suspension model. Consequently, the proposed suspension model could be applied to lightweight bicycles.
System Design and Performance Test of Hydraulic Intensifier
Kim, Hyoung-Eui ; Lee, Gi-Chun ; Kim, Jae-Hoon ;
Transactions of the Korean Society of Mechanical Engineers A, volume 34, issue 7, 2010, Pages 947~952
DOI : 10.3795/KSME-A.2010.34.7.947
Components such as pressure vessel, hydraulic hose assembly, accumulator, hydraulic cylinder, hydraulic valve, pipe, etc., are tested under the impulse-pressure conditions prescribed in ISO and SAE standards. The impulse pressure test machine needs to have a high pressure, a precise control system and a long life. It should satisfy the requirements for fabrication of the impulse tester to generate ultra high pressure in the hydraulic system. In the impulse tester, a servo-valve control system is adopted; although the control application is convenient, it is expensive owing to the cost of developing the system. The type of the control system determines the pressure wave, which affects the components that are tested. In this study, the manufacturing process and the intensifier system design related to the flow, pressure, and the increasing rate of pressure are investigated. The results indicate the ultra high pressure waves in the system.