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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 38, Issue 12 - Dec 2014
Volume 38, Issue 11 - Nov 2014
Volume 38, Issue 10 - Oct 2014
Volume 38, Issue 9 - Sep 2014
Volume 38, Issue 8 - Aug 2014
Volume 38, Issue 7 - Jul 2014
Volume 38, Issue 6 - Jun 2014
Volume 38, Issue 5 - May 2014
Volume 38, Issue 4 - Apr 2014
Volume 38, Issue 3 - Mar 2014
Volume 38, Issue 2 - Feb 2014
Volume 38, Issue 1 - Jan 2014
Selecting the target year
Measurement and Evaluation of Thermal Expansion Coefficient for Warpage Analysis of Package Substrate
Yang, Hee Gul ; Joo, Jin Won ;
Transactions of the Korean Society of Mechanical Engineers A, volume 38, issue 10, 2014, Pages 1049~1056
DOI : 10.3795/KSME-A.2014.38.10.1049
Microelectronics components contain various materials with different coefficients of thermal expansion (CTE). Although a large amount of published data on the CTE of standard materials is available, it occasionally becomes necessary to measure this property for a specific actual material over a particular temperature range. A change in the temperature of a material causes a corresponding change in the output of the strain gage installed on the specimen because of not only the mechanical load but also the temperature change. In this paper, a detailed technique for CTE measurement based on these thermal characteristics of strain gages is proposed and its reliability is evaluated. A steel specimen, aluminum specimen, and copper specimen, whose CTE values are well known, were used in this evaluation. The proposed technique was successfully applied to the measurement of the CTE of a coreless package substrate composing of electronics packages.
Non-Local Plasticity Constitutive Relation for Particulate Composite Material Using Combined Back-Stress Model and Shear Band Formation
Yun, Su-Jin ; Kim, Shin Hoe ; Park, Jae-Beom ; Jung, Gyoo Dong ;
Transactions of the Korean Society of Mechanical Engineers A, volume 38, issue 10, 2014, Pages 1057~1068
DOI : 10.3795/KSME-A.2014.38.10.1057
This paper proposes elastic-plastic constitutive relations for a composite material with two phases-inclusion and matrix phases-using a homogenization scheme. A thermodynamic framework is employed to develop non-local plasticity constitutive relations, which are specifically represented in terms of the second-order gradient terms of the internal state variables. A combined two back-stress evolution equation is also established and the degradation of the state and internal variables is expressed by continuum damage mechanics in terms of the damage factor. Then, deformation localization is analyzed; the analysis results show that the proposed model yields a wide range of shear band formation behaviors depending on the evolution of the specific internal state variables. The analysis results also show good agreement with the results of simplified Rice instability analyses.
Study on Piezoelectric Characteristics of Piezoelectric Paint Sensor According to Poling Time
Han, Dae-Hyun ; Park, Seung-Bok ; Kang, Lae-Hyong ;
Transactions of the Korean Society of Mechanical Engineers A, volume 38, issue 10, 2014, Pages 1069~1074
DOI : 10.3795/KSME-A.2014.38.10.1069
In this study, the piezoelectric characteristics of a piezoelectric paint sensor were investigated in relation to the poling time. This piezoelectric paint sensor was composed of PNN-PZT powder and epoxy resin with a 1:1 weight ratio. The dimensions of the paint specimen were
, and the top and bottom sides were both coated with a silver paste to create electrodes. During the poling treatment, the poling time was controlled to examine the effect of the piezoelectric properties, while the poling temperature was fixed at room temperature and the electric field was set to 4 kV/mm. The piezoelectric properties were measured by comparing the output voltage from the paint sensor to the force signal from an impact hammer when the impact hammer hit the specimen. In conclusion, the optimal poling conditions were found to be an electric field of 4 kV/mm and a poling time of around 30 min at room temperature.
Development of Feature-Based 3D CAD Assembly Data Simplification System for Equipment and Materials
Kim, Byung Chul ; Kwon, Soonjo ; Park, Sunah ; Mun, Duhwan ; Han, Soonhung ;
Transactions of the Korean Society of Mechanical Engineers A, volume 38, issue 10, 2014, Pages 1075~1084
DOI : 10.3795/KSME-A.2014.38.10.1075
It is necessary to construct an equipment catalog in plant design. A different level of detail may be needed for the three-dimensional (3D) computer aided design (CAD) data for equipment, depending on the purpose. Equipment suppliers provide CAD data with high complexity, whereas plant designers need CAD data with low complexity. Therefore, it is necessary to simplify the 3D CAD assembly data. To resolve this issue, a system for automatically simplifying the 3D CAD assembly data of equipment was developed. This paper presents the architecture of the system, the detailed functions of the system, and a neutral data format used for uploading simplified 3D CAD assembly data to a plant 3D CAD system. In addition, experiment results using the prototype system are explained.
Development of Single-Channel Thread Sensor for Rotary Bobbin by Optical Sensing
Jung, Yong-Sub ; Cho, Janghyun ; Byeon, Clare Chisu ;
Transactions of the Korean Society of Mechanical Engineers A, volume 38, issue 10, 2014, Pages 1085~1091
DOI : 10.3795/KSME-A.2014.38.10.1085
We developed a single-channel thread sensor for a rotary bobbin by optical sensing and analyzed the signal characteristics. A specially designed mount made of ABS (acrylonitrile-butadiene-styrene) resin that encapsulated an optical sensor was fabricated by using a 3D printer and was attached to the rotary bobbin system. Stable control on a weaving machine was achieved by observing the difference in the output signals of an optical sensor system, which vary significantly according to the states of the thread in the weaving operation. The optical sensor effectively detects an unintentional thread cut and run-out during weaving fast enough to enable prompt stopping of the weaving machine, thereby minimizing the loss of expensive fabrics.
A Study on the Weight-Reduction Design of High-Speed Maglev Carbody made of Aluminum Extrusion and Sandwich Composite Roof
Kang, SeungGu ; Shin, KwangBok ; Park, KeeJun ; Lee, EunKyu ; Yoon, IllRo ;
Transactions of the Korean Society of Mechanical Engineers A, volume 38, issue 10, 2014, Pages 1093~1100
DOI : 10.3795/KSME-A.2014.38.10.1093
The purpose of this paper is to suggest a weight-reduction design method for the hybrid carbody of a high-speed maglev train that uses aluminum extrusion profiles and sandwich composites. A sandwich composite was used on the roof as a secondary member to minimize the weight. In order to assemble the sandwich composite roof and aluminum extrusion side frame of the carbody using welding, a guide aluminum frame located at the four sides of the sandwich composite roof was introduced in this study. The clamping force of this guide aluminum frame was verified by three-point bending test. The structural integrity and crashworthiness of the hybrid carbody of a high-speed maglev train were evaluated and verified according to the Korean Railway Safety Law using a commercial finite element analysis program. The results showed that the hybrid carbody composed of aluminum extrusion frames and a sandwich composite roof was lighter in weight than a carbody made only of aluminum extrusion profiles and had better structural performance.
Finite Element Analysis of RF Coupler in Normal-Low Temperature
Kim, Hansol ; Lee, Hak Yong ; Park, Chan ; Lee, Jaeyeol ; Lim, Dong Yeal ; Yoo, Jeonghoon ; Hyun, Myung Wook ;
Transactions of the Korean Society of Mechanical Engineers A, volume 38, issue 10, 2014, Pages 1101~1107
DOI : 10.3795/KSME-A.2014.38.10.1101
A heavy ion accelerator is a device that accelerates heavy ions in the radio frequency (RF) range. The electric field that flows into the RF cavity continuously accelerates heavy ions in accordance with the phase of the input electromagnetic wave. For the purpose, it is necessary to design a coupler shape that can stably transfer the RF wave into the cavity. The RF coupler in a heavy ion accelerator has a large temperature difference between the input port and output port, which radiates the RF waves. It is necessary to consider the heat deflection on the RF coupler that occurs as a result of the rapid temperature gradient from an ultra-low temperature about 0 K to a room temperature about 300 K. The purpose of this study was to improve the system performance through an analysis of the intensity of the output electric field and temperature distribution considering various shapes of the RF coupler, along with an analysis of the durability considering the heat deflection and heat loss.
Study on Development of Wheelchair Transfer-Storage Mechanism for Car
Lim, Gu ; Kim, Yong Seok ; Le, QuangHoan ; Jeang, Young Man ; Oh, Dong Kwan ; Oh, Ji Woo ; Yea, Chan Ho ; Yang, Soon Yong ;
Transactions of the Korean Society of Mechanical Engineers A, volume 38, issue 10, 2014, Pages 1109~1116
DOI : 10.3795/KSME-A.2014.38.10.1109
The wheelchair mechanism for a car that is proposed in this study primarily consists of a transfer mechanism and storage mechanism. The wheelchair transfer mechanism consists of a manipulator installed in the roof of a car, and performs the function of transferring the wheelchair from the driver`s seat to the trunk. The wheelchair storage mechanism consists of a lifting hoist installed in the trunk of car, and performs the function of storing the transferred wheelchair in the trunk and safely fastening it in place. This study analyzed and reviewed various manipulators, including a vertical type, Scara type, and telescopic type, with the goal of selecting the best type of manipulator for the wheelchair transfer mechanism. The telescopic type was selected and applied because of its good load support and storage capabilities. In addition, with regard to the wheelchair storage mechanism, a slide hoist type that used a slide rail and lift wire and a rotating link hoist type that used a rotating mechanism consisting of a worm gear and link were analyzed and reviewed. The slide hoist type was selected and applied because it had an advantage in relation to trunk space utilization. This study proposed a wheelchair transfer mechanism for a car to support a conventional wheelchair user`s movements, and in order to conform to the structure of a domestic welfare car for the disabled.
Wear Characteristics According of Heat Treatment of Si
with Different Amounts of SiO
Ahn, Seok Hwan ; Nam, Ki Woo ;
Transactions of the Korean Society of Mechanical Engineers A, volume 38, issue 10, 2014, Pages 1117~1123
DOI : 10.3795/KSME-A.2014.38.10.1117
This study sintered
with different amounts of
nano-colloid. The surface of a mirror-polished specimen was coated with
nano-colloid, and cracks were healed when the specimen was treated at a temperature of 1273 K for 1 h in air. Wear specimen experiments were conducted after heat treatments for 10 min at 1073, 1273, and 1573 K. The heat-treated surface that was coated with the
nano-colloid was slightly rougher than the noncoated surface. The oxidation state of the surface according to the heat treatment temperature showed no correlation with the surface roughness. Moreover, the friction coefficient, wear loss, and bending strength were not related to the surface roughness.
exhibited an abrasive wear behavior when SKD11 was used as an opponent material. The friction coefficient was proportional to the wear loss, and the bending strength was inversely proportional to the friction coefficient and wear loss. The friction coefficient and wear loss increased with increasing amounts of the
nanocolloid. In addition, the friction coefficient was slightly increased by increasing the heat treatment temperature.
Vulnerability Assessment for a Complex Structure Using Vibration Response Induced by Impact Load
Park, Jeongwon ; Koo, Man Hoi ; Park, Junhong ;
Transactions of the Korean Society of Mechanical Engineers A, volume 38, issue 10, 2014, Pages 1125~1131
DOI : 10.3795/KSME-A.2014.38.10.1125
This work presents a vulnerability assessment procedure for a complex structure using vibration characteristics. The structural behavior of a three-dimensional framed structure subjected to impact forces was predicted using the spectral element method. The Timoshenko beam function was applied to simulate the impact wave propagations induced by a high-velocity projectile at relatively high frequencies. The interactions at the joints were analyzed for both flexural and longitudinal wave propagations. Simulations of the impact energy transfer through the entire structure were performed using the transient displacement and acceleration responses obtained from the frequency analysis. The kill probabilities of the crucial components for an operating system were calculated as a function of the predicted acceleration amplitudes according to the acceptable vibration levels. Following the proposed vulnerability assessment procedure, the vulnerable positions of a three-dimensional combat vehicle with high possibilities of damage generation of components by impact loading were identified from the estimated vibration responses.
Measurement of Ultrasonic Nonlinear Parameter by Using Non-Contact Ultrasonic Receiver
Kim, Jongbeom ; Jhang, Kyoung-Young ;
Transactions of the Korean Society of Mechanical Engineers A, volume 38, issue 10, 2014, Pages 1133~1137
DOI : 10.3795/KSME-A.2014.38.10.1133
The ultrasonic nonlinear parameter
is generally known as an effective parameter for evaluating material degradation. Thus far, most research has been conducted using a contact method. However, since measurement by this contact method is affected by the contact conditions between the transducer and the specimen, additional devices are required to maintain the contact conditions stable during the measurement. To avoid this inconvenience, this paper proposes a noncontact method. In this study, only the receiver was replaced with a noncontact receiver, and then, the ultrasonic nonlinear parameters measured by the newly developed noncontact receiver were compared with those measured by the contact receiver. Results obtained using both these receivers for heat-treated aluminum alloy specimens showed good agreement. From this result, we can confirm that the ultrasonic nonlinear parameter
can be measured using the proposed noncontact ultrasonic method.
Parametric Shape Modeling of Femurs Using Statistical Shape Analysis
Choi, Myung Hwan ; Koo, Bon Yeol ; Chae, Je Wook ; Kim, Jay Jung ;
Transactions of the Korean Society of Mechanical Engineers A, volume 38, issue 10, 2014, Pages 1139~1145
DOI : 10.3795/KSME-A.2014.38.10.1139
Creation of a human skeleton model and characterization of the variation in the bone shape are fundamentally important in many applications of biomechanics. In this paper, we present a parametric shape modeling method for femurs that is based on extracting the main parameter of variations of the femur shape from a 3D model database by using statistical shape analysis. For this shape analysis, principal component analysis (PCA) is used. Application of the PCA to 3D data requires bringing all the models in correspondence to each other. For this reason, anatomical landmarks are used for guiding the deformation of the template model to fit the 3D model data. After subsequent application of PCA to a set of femur models, we calculate the correlation between the dominant components of shape variability for a target population and the anatomical parameters of the femur shape. Finally, we provide tools for visualizing and creating the femur shape using the main parameter of femur shape variation.
Estimation of Human Lower-Extremity Muscle Force Under Uncertainty While Rising from a Chair
Jo, Young Nam ; Kang, Moon Jeong ; Chae, Je Wook ; Yoo, Hong Hee ;
Transactions of the Korean Society of Mechanical Engineers A, volume 38, issue 10, 2014, Pages 1147~1155
DOI : 10.3795/KSME-A.2014.38.10.1147
Biomechanical models are often used to predict muscle and joint forces in the human body. For estimation of muscle forces, the body and muscle properties have to be known. However, these properties are difficult to measure and differ from person to person. Therefore, it is necessary to predict the change in muscle forces depending on the body and muscle properties. The objective of the present study is to develop a numerical procedure for estimating the muscle forces in the human lower extremity under uncertainty of body and muscle properties during rising motion from a seated position. The human lower extremity is idealized as a multibody system in which eight Hill-type muscle force models are employed. Each model has four degrees of freedom and is constrained in the sagittal plane. The eight muscle forces are determined by minimizing the metabolic energy consumption during the rising motion. Uncertainty analysis is performed using a first-order reliability method. The one-standard-deviation range of agonistic muscle forces is calculated to be about 150-300 N.
Review of Acceleration Methods for Seismic Analysis of Through-Wall Cracked Piping from the Viewpoint of Linear Elastic Fracture Mechanics
Kim, Jong Sung ; Kim, Yong Woo ;
Transactions of the Korean Society of Mechanical Engineers A, volume 38, issue 10, 2014, Pages 1157~1162
DOI : 10.3795/KSME-A.2014.38.10.1157
Two acceleration methods, an effective force method (or inertia method) and a large mass method, have been applied for performing time history seismic analysis. The acceleration methods for uncracked structures have been verified via previous studies. However, no study has identified the validity of these acceleration methods for cracked piping. In this study, the validity of the acceleration methods for through-wall cracked piping is assessed via time history implicit dynamic elastic seismic analysis from the viewpoint of linear elastic fracture mechanics. As a result, it is identified that both acceleration methods show the same results for cracked piping if a large mass magnitude and maximum time increment are adequately selected.
Fatigue Assessment of High Strength Steel Welded Joints Under Bending Loading
Lee, Myeong-Woo ; Kim, Yun-Jae ; Park, Jun-Hyub ;
Transactions of the Korean Society of Mechanical Engineers A, volume 38, issue 10, 2014, Pages 1163~1169
DOI : 10.3795/KSME-A.2014.38.10.1163
In this study, a fatigue assessment method for vehicle suspension systems having welded geometries was established under a bending loading condition. For the fatigue life estimation of the actual product`s welded joints made of different steels, bending fatigue tests were performed on welded specimens with a simplified shape for obtaining the moment-fatigue-life plot. Further, geometry modeling of the simplified welded specimens was conducted. Results of finite element analysis were used to obtain the stress-fatigue-life plot. The analysis results were also used to calculate the stress concentration factors for notch-factor-based fatigue life estimation. The test results were compared with results of the general notch-factor-based fatigue life estimation for improving fatigue assessment. As a result, it was concluded that both the welded fatigue tests and the notch-factor-based fatigue life estimation are necessary for accurate fatigue assessment.
Reliability Demonstration Test Method for Electromagnetic Shielding Doorset with a Sub-Unit Subjected to Preventive Replacement
Shin, Jung-Hun ; Lee, Hyo-Kyung ; Jang, Jin ; Kim, Do-Sik ; Nam, Tae-Yeon ; Jung, Dong-Soo ;
Transactions of the Korean Society of Mechanical Engineers A, volume 38, issue 10, 2014, Pages 1171~1177
DOI : 10.3795/KSME-A.2014.38.10.1171
An electromagnetic shielding doorset must satisfy requirements associated with both mechanical strength/durability and electromagnetic shielding. Among the primary components of the doorset, a finger strip-a leaftype spring normally made of beryllium copper-is a core part to shield electromagnetic waves as well as to endure repetitive dry sliding friction. This study presented a reliability demonstration test method for the doorset system and, by a simple and simultaneous implementation, of the replacement interval of the finger strip. A rigorous evaluation for the qualification of maintenance or replacement interval is included in the reliability demonstration test of any series system that holds critical maintenance sub-units.
Reliability Allocation for KTX Door System
Jang, Mu-Seong ; Choi, Byung Oh ; Lee, Jeong Hun ;
Transactions of the Korean Society of Mechanical Engineers A, volume 38, issue 10, 2014, Pages 1179~1184
DOI : 10.3795/KSME-A.2014.38.10.1179
Reliability allocation is generally used during the early stage of system development to apportion the system reliability target to its individual modules. This paper presents a comprehensive method for performing the reliability allocation of KTX door systems. Nine criteria for reliability allocation include failure criticality, operating time, risk, complexity, failure rate, maintenance, manufacturing technology, working condition, and reliability cost. For satisfying the system reliability target, the allocated
lives of four modules are provided.
Life Assessment of Gas Turbine Blade Based on Actual Operation Condition
Choi, Woo Sung ; Song, Gee Wook ; Chang, Sung Yong ; Kim, Beom Soo ;
Transactions of the Korean Society of Mechanical Engineers A, volume 38, issue 10, 2014, Pages 1185~1191
DOI : 10.3795/KSME-A.2014.38.10.1185
Gas turbine blades that have complex geometry of the cooling holes and cooling passages are usually subjected to cyclic and sustained thermal loads due to changes in the operating characteristic in combined power plants; these results in non-uniform temperature and stress distributions according to time to gas turbine blades. Those operation conditions cause creep or thermo-mechanical fatigue damage and reduce the lifetime of gas turbine blades. Thus, an accurate analysis of the stresses caused by various loading conditions is required to ensure the integrity and to ensure an accurate life assessment of the components of a gas turbine. It is well known that computational analysis such as cross-linking process including CFD, heat transfer and stress analysis is used as an alternative to demonstration test. In this paper, temperatures and stresses of gas turbine blade were calculated with fluid-structural analysis integrating fluid-thermal-solid analysis methodologies by considering actual operation conditions. Based on analysis results, additionally, the total lifetime was obtained using creep and thermo-mechanical damage model.