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 37, Issue 12 - Dec 2013
Volume 37, Issue 11 - Nov 2013
Volume 37, Issue 10 - Oct 2013
Volume 37, Issue 9 - Sep 2013
Volume 37, Issue 8 - Aug 2013
Volume 37, Issue 7 - Jul 2013
Volume 37, Issue 6 - Jun 2013
Volume 37, Issue 5 - May 2013
Volume 37, Issue 4 - Apr 2013
Volume 37, Issue 3 - Mar 2013
Volume 37, Issue 2 - Feb 2013
Volume 37, Issue 1 - Jan 2013
Selecting the target year
Electrochemical Combined-Stress Degradation Test and Failure Mechanisms of EPDM Rubber for Automotive Radiator Hoses
Kwak, Seung Bum ; Choi, Nak Sam ; Shin, Sei Moon ;
Transactions of the Korean Society of Mechanical Engineers A, volume 37, issue 1, 2013, Pages 1~8
DOI : 10.3795/KSME-A.2013.37.1.001
Coolant rubber hoses for automotive radiators can degrade under thermal and mechanical loadings and thus fail owing to the influences of locally formed electricity. In this study, an advanced test method was developed to simulate the failure of a rubber hose. The aging behavior of carbon-black-filled ethylene-propylene diene monomer (EPDM) rubber used as a radiator hose material under a combination of electrochemical stresses and tensile strain was analyzed. The changing behaviors of the current and the resistance as a function of the aging time were analyzed in consideration of the tensile strain, voltage, and aging temperature. Sectioned specimens clarified the failure mechanisms of the aged skin layer under the combined electrochemical stresses.
Analysis of Two-Way Fluid-Structure Interaction and Local Material Properties of Brazed Joints for Estimation of Mechanical Integrity
Kang, Seok Hoon ; Park, Sang Hu ; Min, June Kee ; Jeong, Ho Sung ; Son, Chang Min ; Ha, Man-Young ; Cho, JongRae ; Kim, Hyun Jun ;
Transactions of the Korean Society of Mechanical Engineers A, volume 37, issue 1, 2013, Pages 9~16
DOI : 10.3795/KSME-A.2013.37.1.009
Recent years have witnessed a strong need for eco-friendly and energy-efficient systems owing to global environmental problems. A heat exchanger is a well-known mechanical rig that has long been used in many energy systems. The use of a heat exchanger in an airplane engine has been attempted. In this case, the heat exchanger should be redesigned to be compact, lightweight, and highly reliable, and the issue of mechanical integrity gains importance. Therefore, in this study, we proposed a method for evaluating the mechanical integrity of a tube-type heat exchanger. A U-shaped single tube was used as an example, and its behavior and stress distribution were studied using fluid-structure interaction (FSI) analysis.
Lateral Damper of Subway Vehicle for Preventing Abnormal Impact
Shin, Yujeong ; You, Wonhee ; Park, Joonhyuk ; Hur, Hyunmoo ; Jeon, Juyun ;
Transactions of the Korean Society of Mechanical Engineers A, volume 37, issue 1, 2013, Pages 17~23
DOI : 10.3795/KSME-A.2013.37.1.017
In a subway vehicle, a lateral damper is used for compensating the lateral stiffness deterioration due to the air-spring as a secondary suspension. This lateral damper can reduce the lateral vibration of the carbody. When the damping force of the lateral damper is lowered, the running stability and ride quality of the subway vehicles worsens and the lateral motion of the carbody is increased. In this study, the lateral displacement variation of the carbody according to the damping force of the lateral damper was analyzed by multi-body dynamics to solve the abnormal impact problem during vehicle operation. Furthermore, the noise and vibration due to abnormal impact were considered. An adequate damping coefficient of the lateral damper for the subway vehicle treated in this paper was suggested for preventing abnormal impact.
Vibration Reduction Technique for Rotating Suspension Vehicles with a Modified Skyhook Controller
Jung, Samuel ; Yoo, Wan-Suk ;
Transactions of the Korean Society of Mechanical Engineers A, volume 37, issue 1, 2013, Pages 25~30
DOI : 10.3795/KSME-A.2013.37.1.025
In military vehicles moving over poor roads, severe vibration of the chassis can damage internal components. Currently, many studies have focused on active and semi-active suspensions to reduce the vibration of the chassis. In this study, a vibration reduction technique is suggested by applying a unique rotating suspension structure. SH-ADD, a type of modified Skyhook, was selected as a controller for vibration reduction. A random ISO class E road was selected as the driving road. The simulation was performed using ADAMS Control and Matlab Simulink. The control result was compared with the RMS acceleration with a focus on the cumulative fatigue of the internal equipment.
Study of Size Optimization for Skirt Structure of Composite Pressure Vessel
Kim, Jun Hwan ; Shin, Kwang Bok ; Hwang, Tae Kyung ;
Transactions of the Korean Society of Mechanical Engineers A, volume 37, issue 1, 2013, Pages 31~37
DOI : 10.3795/KSME-A.2013.37.1.031
This study aims to find the optimal skirt dimensions for a composite pressure vessel with a separated dome part. The size optimization for the skirt structure of the composite pressure vessel was conducted using a sub-problem approximation method and batch processing codes programmed using ANSYS Parametric Design Language (APDL). The thickness and length of the skirt part were selected as design variables for the optimum analysis. The objective function and constraints were chosen as the weight and the displacement of the skirt part, respectively. The numerical results showed that the weight of the skirt of a composite pressure vessel with a separated dome part could be reduced by a maximum of 4.38% through size optimization analysis of the skirt structure.
Development of Plastic Lenses for High-Resolution Phone Camera by Injection-Compression Molding
Lee, Ho Sang ; Jeon, Won Taek ; Kim, Sung Woo ;
Transactions of the Korean Society of Mechanical Engineers A, volume 37, issue 1, 2013, Pages 39~46
DOI : 10.3795/KSME-A.2013.37.1.039
This study aims to develop a plastic aspheric lens for a 13-megapixel mobile phone camera by injection-compression molding. A mold for injection-compression molding experiments was fabricated with a movable upper plate and four springs. During cavity filling for an aspheric lens with a thickness ratio of 2, a weldline was formed under conventional injection molding, whereas no weldline was formed under injection-compression molding with a compression stroke of 0.3 mm. The flow patterns were in good agreement with the simulation results. The birefringence decreased as the compression stroke increased, and the birefringence produced by injection-compression molding was very low and more uniform compared with that produced by injection molding. In addition, the bulk birefringence of an assembly composed of four plastic lenses was significantly affected by the orientation of the lenses to be mounted.
Crack Growth Analysis due to PWSCC in Dissimilar Metal Butt Weld for Reactor Piping Considering Hydrostatic and Normal Operating Conditions
Lee, Hwee-Sueng ; Huh, Nam-Su ; Lee, Seung-Gun ; Park, Heung-Bae ; Lee, Sung-Ho ;
Transactions of the Korean Society of Mechanical Engineers A, volume 37, issue 1, 2013, Pages 47~54
DOI : 10.3795/KSME-A.2013.37.1.047
This study investigates the crack growth behavior due to primary water stress corrosion cracking (PWSCC) in the dissimilar metal butt weld of a reactor piping using Alloy 82/182. First, detailed finite element stress analyses were performed to predict the stress distribution of the dissimilar metal butt weld in which the hydrostatic and the normal operating loads as well as the weld residual stresses were considered to evaluate the stress redistribution due to mechanical loadings. Based on the stress distributions along the wall thickness of the dissimilar metal butt weld, the crack growth behavior of the postulated axial and circumferential cracks were predicted, from which the crack growth diagram due to PWSCC was proposed. The present results can be applied to predict the crack growth rate in the dissimilar metal butt weld of reactor piping due to PWSCC.
Kinematic Analysis of Levering Systems in Compound Bows
Lee, Yong-Sung ; Kim, Hong Seok ; Cheong, Seong-Kyun ; Choi, Ung-Jae ; Kim, Young-Keun ; Park, Kyung-Rea ; Shin, Ki-Hoon ;
Transactions of the Korean Society of Mechanical Engineers A, volume 37, issue 1, 2013, Pages 55~60
DOI : 10.3795/KSME-A.2013.37.1.055
Compound bows use levering systems consisting of cables and cam pulleys to bend limbs that are much stiffer than those of recurve bows, thus storing more energy while requiring less force for the archer to hold the bow at a fully drawn position. Many patents have thus far been proposed to improve the efficiency and performance of compound bows through empirical methods, whereas only a few analytical methods have been proposed. In this light, this paper presents a method for the kinematic analysis of levering systems in compound bows so that a designer can easily predict the effects of changes in the cam profiles and limb materials.
Fabrication of Functionally Graded Materials Between P21 Tool Steel and Cu by Using Laser-Aided Layered Manufacturing
Jeong, Jong-Seol ; Shin, Ki-Hoon ;
Transactions of the Korean Society of Mechanical Engineers A, volume 37, issue 1, 2013, Pages 61~66
DOI : 10.3795/KSME-A.2013.37.1.061
With the development of layered manufacturing, thermally conductive molds or molds embedding conformal cooling channels can be directly fabricated. Although P21 tool steel is widely used as a mold material because of its dimensional stability, it is not efficient for cooling molds owing to its low thermal conductivity. Hence, the use of functionally graded materials (FGMs) between P21 and Cu may circumvent a tradeoff between the strength and the heat transfer rate. As a preliminary study for the layered manufacturing of thermally conductive molds having FGM structures, one-dimensional P21-Cu FGMs were fabricated by using laser-aided direct metal tooling (DMT), and then, material properties such as the thermal conductivity and specific heat that are related to the heat transfer were measured and analyzed.
Determination of Flow Stress of Zircaloy-4 Under High Strain Rate Using Slot Milling Test
Hwang, Jihoon ; Kim, Naksoo ; Lee, Hyungyil ; Kim, Dongchoul ;
Transactions of the Korean Society of Mechanical Engineers A, volume 37, issue 1, 2013, Pages 67~75
DOI : 10.3795/KSME-A.2013.37.1.067
The flow stress of zircaloy-4 used in the spacer grid supporting a nuclear fuel rod was determined by the Johnson-Cook model, and model parameters were determined using reverse engineering. Parameters such as A, B, n and
were determined by the tensile test result. To obtain the parameters C and m, a slot milling test and numerical simulation were performed. The objective functions were defined as the difference between the experimental and the simulation results, and then, the parameters were determined by minimizing the objective function. To verify the validity of the determined parameters, cross-verification for each case was conducted through a shearing test and simulation. The results tend to show agreement with the experimental results, such as the features of sheared edges and maximum punch force, with the correlation coefficients exceeding at least 0.97.
Theoretical Analysis and Experimental Evaluation of Small Cyclone Separator to Remove Fine Particulate Matter
Ko, Han Gyul ; Kim, Hong Seok ;
Transactions of the Korean Society of Mechanical Engineers A, volume 37, issue 1, 2013, Pages 77~82
DOI : 10.3795/KSME-A.2013.37.1.077
A cyclone separator has been widely used in various industrial processes for removing fine particulate matter because it is easy to fabricate, cost effective, and adaptable to extremely harsh conditions. However, owing to the complex flow field in cyclones, a complete understanding of the detailed mechanisms of particulate removal has not yet been gained. In this study, a theoretical analysis was performed for calculating the collection efficiency and cut-off size in cyclones by taking into account the effects of geometrical and flow parameters. The collection efficiency and cut-off size values predicted by the theoretical model showed good agreement with experimental measurements for particles with a diameter of
. It was also revealed that the surface friction, along with the flow and geometrical parameters, has a significant effect on the cyclone performance.
Evaluation of Post-Buckling Residual Strength of H-Section Steel Column for Both Ends are Fixed Condition
Abebe, Daniel Yeshewawork ; Choi, Jae Hyouk ; Kim, Jin Hyang ;
Transactions of the Korean Society of Mechanical Engineers A, volume 37, issue 1, 2013, Pages 83~88
DOI : 10.3795/KSME-A.2013.37.1.083
Progressive collapse is a chain reaction of failures propagating throughout a portion of a structure that is disproportionate to the original local failure. When column members are subjected to unexpected load (compression load), they will buckle if the applied load is greater than the critical load that induces buckling. The post-buckling strength of the columns will decrease rapidly, but if there is enough residual strength, the members will absorb the potential energy generated by the impact load to prevent progressive collapse. Thus, it is necessary to identify the relationship of the load-deformation of a column member in the progressive collapse of a structure up to final collapse. In this study, we carried out nonlinear FEM analysis and based on deflection theory, we investigated the load-deformation relationship of H-section steel columns when both ends were fixed.
Study of Local Performance Index of 2-DOF Parallel Manipulator
Lee, Jong Gyu ; Yang, Seung Han ; Lee, Sang Ryong ; Lee, Choon Young ;
Transactions of the Korean Society of Mechanical Engineers A, volume 37, issue 1, 2013, Pages 89~95
DOI : 10.3795/KSME-A.2013.37.1.089
This study investigates a parallel manipulator that can move over two parallel sliders and in which the end-effector of the manipulator can be adjusted arbitrarily. Through the direct and inverse kinematics of the manipulator, position equations are derived. These equations represent the relationship between the positions of the sliders and the position of the end-effector. The Jacobian matrices of the direct and inverse kinematics are obtained by these equations. By using the condition number defined from these matrices, the local performance index of the manipulator is proposed. By using the simulation results of the performance index, we find that the manipulator can smoothen movements in only one quadrant and that the distribution of the maximal performance index is affected by the ratio of the length of links and the orientation of the end-effector.
Conical Path Generation Technique for Ball Bar Measurement Using Simultaneous 5-Axis Motion Control
Lee, Dong-Mok ; Lee, Jae-Chang ; Yang, Seung-Han ;
Transactions of the Korean Society of Mechanical Engineers A, volume 37, issue 1, 2013, Pages 97~103
DOI : 10.3795/KSME-A.2013.37.1.097
This study proposes a path generation technique for simultaneous five-axis driving for ball bar measurement, which is equivalent to cone frustum machining as mentioned in the NAS979 standard. The technique is generalized for a 3D circular path, and it is applicable to all machine tools regardless of their structural configurations. A mathematical machine input model that consists of a five-axis machine tool, ball-bar measurement and conical path information as inputs is presented for easy NC code generation, simulation for various test conditions, and a measurement test. The movement range of rotary axes, which depends on various conditions, is mathematically analyzed based on the proposed conical path model. Moreover, the effect of the movement range on various conditions (apex angle and inclination angle, ball bar tilting acceptance angle, offset position of workpiece ball, etc.) is analyzed.
Static and Dynamic Analysis and Optimization Design of 40,000-rpm High-Speed Spindle for Machine Tools
Kim, Dong Hyeon ; Lee, Choon Man ; Choi, Hyun Jin ;
Transactions of the Korean Society of Mechanical Engineers A, volume 37, issue 1, 2013, Pages 105~111
DOI : 10.3795/KSME-A.2013.37.1.105
The spindle is the main component in machine tools. The static and dynamic characteristics of the spindle directly affect the machining accuracy of workpieces. The characteristics of the spindle depend on the shaft size, bearing span, built-in motor location, and so on. Therefore, the appropriate selection of these parameters is important to improve the spindle characteristics. This paper presents the analysis of the static and dynamic characteristics and optimization design of a 40,000-rpm high-speed spindle. Statistical analysis for optimization and finite element analysis were performed. This study uses the response surface method to optimize the objective function and design factors. The targets are the natural frequency and displacement. The design factors are the shaft length, shaft diameter, bearing span, and motor location. The optimized design provides better results than the initial model, and these results are expected to improve the static and dynamic characteristics of the spindle.
Development of Web-Based Platform System for Sharing Manufacturing Technologies on Housing Parts of Mobile Products
Jung, Tae Sung ; Yoon, Gil Sang ; Heo, Young Moo ; Lee, Hyo Soo ; Kang, Moon Jin ;
Transactions of the Korean Society of Mechanical Engineers A, volume 37, issue 1, 2013, Pages 113~119
DOI : 10.3795/KSME-A.2013.37.1.113
Despite rapid changes in the structure of industry, manufacturing remains a key industry for economic progress, promotion of trade, increased employment, and the creation of new industries. Production technologies are essential for strengthening the competitiveness of small- and medium-sized manufacturing industries. However, it is very difficult to standardize and systematically propagate production technology from an experienced worker to an inexperienced worker because these technologies are generally improved by the skilled people in a workshop. In this study, we introduce a Web-based platform system consisting of a knowledge authoring tool, technology database, semantic database, and Web portal service for sharing production technologies for the exterior housing parts of mobile products. By investigating various cellular phone designs, reference form factors for three types of mobile phone housings were designed based on the standard features. In addition, several manufacturing technologies and considerable information such as reference mold designs and molding conditions optimized using CAE and recent R&D outputs are stored in this system.
Utilization of Finite Element Analysis in Design and Performance Evaluation of CFRP Bicycle Frames
Lee, Yong-Sung ; Shin, Ki-Hoon ; Cheong, Seong-Kyun ; Choi, Ung-Jae ; Kim, Young-Keun ; Park, Kyung-Rea ; Kim, Hong Seok ;
Transactions of the Korean Society of Mechanical Engineers A, volume 37, issue 1, 2013, Pages 121~127
DOI : 10.3795/KSME-A.2013.37.1.121
With the continuing demand for lightweight bicycles, carbon fiber composite materials have been widely used in manufacturing bicycle frames and components. Unlike general isotropic materials, the structural characteristics of composite materials are strongly influenced by the staking directions and sequences of composite laminates. Thus, to verify the design process of bicycles manufactured using composites, structural analysis is considered essential. In this study, a carbon-fiber-reinforced plastic (CFRP) bicycle frame was designed and its structural behavior was investigated using finite element analysis (FEA). By measuring the failure indices of the fiber and matrix under various stacking sequences and loading conditions, the effect of the stacking condition of composite laminates on the strength of the bicycle structure was examined. In addition, the structural safety of the bicycle frame can be enhanced by reinforcing weak regions prone to failure using additional composite laminates.
An Optimal Design of the Curtain Airbag System Using the Response Surface Method
Yun, Yong-Won ; Park, Gyung-Jin ;
Transactions of the Korean Society of Mechanical Engineers A, volume 37, issue 1, 2013, Pages 129~135
DOI : 10.3795/KSME-A.2013.37.1.129
There is not enough absorption space in the side of a vehicle so injuries to a passenger are higher compared to frontal impact injuries. For the protection of the passenger in the event of a side impact, vehicle regulations and new car assessment program(NCAP) are implemented all over the world. However, passive safety such as absorption technology of vehicle body itself is limited due to the narrow space of the side part. At the present time, it is well known that a side airbag including a curtain airbag is the most effective system to protect the passenger during a side impact. In this study, optimum design of the curtain airbag is carried out to reduce Head Injury Criterion(HIC) of the passenger. Based on crashworthiness simulation, an orthogonal array is selected based on the defined design variables, the response surfaces are generated from the orthogonal array and optimization is conducted with the surfaces.