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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 33, Issue 12 - Dec 2009
Volume 33, Issue 11 - Nov 2009
Volume 33, Issue 10 - Oct 2009
Volume 33, Issue 9 - Sep 2009
Volume 33, Issue 8 - Aug 2009
Volume 33, Issue 7 - Jul 2009
Volume 33, Issue 6 - Jun 2009
Volume 33, Issue 5 - May 2009
Volume 33, Issue 4 - Apr 2009
Volume 33, Issue 3 - Mar 2009
Volume 33, Issue 2 - Feb 2009
Volume 33, Issue 1 - Jan 2009
Selecting the target year
Comparison of Fatigue Strength Criteria for TiNi/Al6061-T6 and TiNi/Al2024-T4 Shape Memory Alloy Composite
Jo, Young-Jik ; Park, Young-Chul ;
Transactions of the Korean Society of Mechanical Engineers A, volume 33, issue 2, 2009, Pages 99~107
DOI : 10.3795/KSME-A.2009.33.2.99
This study produced a design curve and fatigue limit for a variation in volume ratio and reduction ratio of TiNi/Al composites. In many cases, stress-life curve does not indicate fatigue limit, so it was presented by probabilistic-stress-life curve. Goodman diagram was used to analyze the fatigue strength of materials with a finite life determined by repeated load and the fatigue strength of endurance limit with an infinite life. The fatigue experiment was conducted using the scenk-type plane bending specimen in same shape. The result of the fatigue test, which had been conducted under consistent stress amplitude, was examined. (i) The optimal condition for TiNi/Al in accordance with hot pressing (ii) Impacts of fatigue limit caused by a variation in reduction ratio and volume ratio of TiNi/Al composites (iii) Probability distribution for fatigue limit of TiNi/Al2024 and TiNi/Al6061.
Mixing of Materials in FSW of Dissimilar Aluminum Alloys
Hong, Sung-Tae ;
Transactions of the Korean Society of Mechanical Engineers A, volume 33, issue 2, 2009, Pages 108~113
DOI : 10.3795/KSME-A.2009.33.2.108
The mixing of two dissimilar aluminum alloys in friction stir welding (FSW) was investigated using etching. The results show that the materials from the retreating side mixed into the advancing side in rather narrow and elongated bands whereas the materials from the advancing side mixed into the retreating side in the form of thick bands and lobes. A computational method using smoothed particle hydrodynamics (SPH) is introduced as a way to properly describe the complex mixing behavior in FSW.
Response Surface Approximation for Fatigue Life Prediction and Its Application to Multi-Criteria Optimization With a Priori Preference Information
Baek, Seok-Heum ; Cho, Seok-Swoo ; Joo, Won-Sik ;
Transactions of the Korean Society of Mechanical Engineers A, volume 33, issue 2, 2009, Pages 114~126
DOI : 10.3795/KSME-A.2009.33.2.114
In this paper, a versatile multi-criteria optimization concept for fatigue life prediction is introduced. Multi-criteria decision making in engineering design refers to obtaining a preferred optimal solution in the context of conflicting design objectives. Compromise decision support problems are used to model engineering decisions involving multiple trade-offs. These methods typically rely on a summation of weighted attributes to accomplish trade-offs among competing objectives. This paper gives an interpretation of the decision parameters as governing both the relative importance of the attributes and the degree of compensation between them. The approach utilizes a response surface model, the compromise decision support problem, which is a multi-objective formulation based on goal programming. Examples illustrate the concepts and demonstrate their applicability.
T-spline Finite Element Method for CAD/CAE Integrated Approach
Uhm, Tae-Kyoung ; Kim, Ki-Seung ; Seo, Yu-Deok ; Youn, Sung-Kie ;
Transactions of the Korean Society of Mechanical Engineers A, volume 33, issue 2, 2009, Pages 127~134
DOI : 10.3795/KSME-A.2009.33.2.127
T-splines are recently proposed geometric modeling tools. A T-spline surface is a NURBS surface with T-junctions and is defined by a control grid called T-mesh. Local refinement can be performed very easily for T-splines while it is limited for B-splines or NURBS. Using T-splines, patches with unmatched boundaries can be combined easily without special technique. In this study, the analysis methodology using T-splines is proposed. In this methodology, T-splines are used both for description of geometries and for approximation of solution spaces. Two-dimensional linear elastic and dynamic problems will be solved by employing the proposed T-spline finite element method, and the effectiveness of the current analysis methodology will be verified.
T-spline FEA for Trimmed NURBS Surface
Kim, Hyun-Jung ; Seo, Yu-Deok ; Youn, Sung-Kie ;
Transactions of the Korean Society of Mechanical Engineers A, volume 33, issue 2, 2009, Pages 135~144
DOI : 10.3795/KSME-A.2009.33.2.135
In this present work, spline FEA for the trimmed NURBS surface of the 2D linear elasticity problem is presented. The main benefit of the proposed method is that no additional efforts for modeling of trimmed NURBS surfaces are needed and the information of the trimming curves and trimmed surfaces exported from the CAD system can be directly used for analysis. For this, trimmed elements are searched by using NURBS projection scheme. The integration of the trimmed elements is performed by using the NURBS-enhanced integration scheme. The formulation of constructing stiffness matrix of trimmed elements is presented. In this formulation, the information of the trimming curve is used for calculating the Jacobian as well as for obtaining integration points. The robustness and effectiveness of the proposed method are investigated through various numerical examples.
Analysis of Elastic-Plastic J Integrals for 3-Dimensional Cracks Using Finite Element Alternating Method
Park, Jai-Hak ;
Transactions of the Korean Society of Mechanical Engineers A, volume 33, issue 2, 2009, Pages 145~152
DOI : 10.3795/KSME-A.2009.33.2.145
SGBEM(Symmetric Galerkin Boundary Element Method)-FEM alternating method has been proposed by Nikishkov, Park and Atluri. In the proposed method, arbitrarily shaped three-dimensional crack problems can be solved by alternating between the crack solution in an infinite body and the finite element solution without a crack. In the previous study, the SGBEM-FEM alternating method was extended further in order to solve elastic-plastic crack problems and to obtain elastic-plastic stress fields. For the elastic-plastic analysis the algorithm developed by Nikishkov et al. is used after modification. In the algorithm, the initial stress method is used to obtain elastic-plastic stress and strain fields. In this paper, elastic-plastic J integrals for three-dimensional cracks are obtained using the method. For that purpose, accurate values of displacement gradients and stresses are necessary on an integration path. In order to improve the accuracy of stress near crack surfaces, coordinate transformation and partitioning of integration domain are used. The coordinate transformation produces a transformation Jacobian, which cancels the singularity of the integrand. Using the developed program, simple three-dimensional crack problems are solved and elastic and elastic-plastic J integrals are obtained. The obtained J integrals are compared with the values obtained using a handbook solution. It is noted that J integrals obtained from the alternating method are close to the values from the handbook.
Finite Element Analysis and Validation for Dimpled Tube Type Intercooler Using Homogenization Method
Lee, Hyun-Min ; Heo, Seong-Chan ; Song, Woo-Jin ; Ku, Tae-Wan ; Kang, Beom-Soo ; Kim, Jeong ;
Transactions of the Korean Society of Mechanical Engineers A, volume 33, issue 2, 2009, Pages 153~161
DOI : 10.3795/KSME-A.2009.33.2.153
Three-dimensional finite-element methods(FEM) have been used to analyze the thermal stress of an exhaust gas recirculation(EGR) cooler due to thermal and pressure load. Since efficiency and capability of the heat exchanger are mainly dependent on net heat transferring area of the EGR cooler system, the tube inside the system has a numerous dimples on the surface. Thus for finite element analysis, firstly the dimple-typed tube is modeled as a plain element without the dimple, and then the equivalent thermal conductivities and elastic modulus are calculated. This work describes the numerical homogenization procedure of the dimple-typed tube and verifies the equivalent material properties by comparison of a single unit and the actual full model. Finally, the homogenization scheme presented in this study can be efficiently applied to finite element analyses for the thermal stress and deformation behavior of the EGR cooler system with the dimple-typed tube.
Evaluation on the Delamination Life of Isothermally Aged Plasma Sprayed Thermal Barrier Coating
Kim, Dae-Jin ; Shin, In-Hwan ; Koo, Jae-Mean ; Seok, Chang-Sung ; Kim, Moon-Young ;
Transactions of the Korean Society of Mechanical Engineers A, volume 33, issue 2, 2009, Pages 162~168
DOI : 10.3795/KSME-A.2009.33.2.162
In this study, disk type of thermal barrier coating system for gas turbine blade was isothermally aged in the furnace changing exposure time and temperature. The aging conditions that delamination occurs were determined by the extensive microscopic analyses and bond tests for each aging condition. The delamination map was drawn from the time-temperature matrix form which summarize the delamination conditions. Finally, a method to draw the delamination life diagram of a thermal barrier coating system by using the delamination map was suggested.
Anti-skid Control System Analysis of a Tilting Train
Kang, Chul-Goo ; Kim, Ho-Yeon ; Kim, Min-Soo ; Goo, Byeong-Choon ;
Transactions of the Korean Society of Mechanical Engineers A, volume 33, issue 2, 2009, Pages 169~178
DOI : 10.3795/KSME-A.2009.33.2.169
The presence of low adhesion at the wheel-rail contact point can result in skid of train wheels, and the skid, in turn, results in flats appearing on the wheels. Thus, anti-skid control has a crucial role for safe braking and prevention from flats that could cause a disastrous train accident. This paper presents dynamic modeling of a tilting train and the brake system of the tilting train, and analyzes the anti-skid logic used in the tilting train. The validity of the analysis is demonstrated via simulation study using Simulink for skid and re-adhesion circumstances of the tilting train.
The Assembly and Test of Pressure Vessel for Irradiation
Park, Kook-Nam ; Lee, Jong-Min ; Youn, Young-Jung ; June, Hyung-Kil ; Ahn, Sung-Ho ; Lee, Kee-Hong ; Kim, Young-Ki ; Kennedy, Timothy C. ;
Transactions of the Korean Society of Mechanical Engineers A, volume 33, issue 2, 2009, Pages 179~184
DOI : 10.3795/KSME-A.2009.33.2.179
The Fuel Test Loop(FTL) which is capable of an irradiation testing under a similar operating condition to those of PWR(Pressurized Water Reactor) and CANDU(CANadian Deuterium Uranium reactor) nuclear power plants has been developed and installed in HANARO, KAERI(Korea Atomic Energy Research Institute). It consists of In-Pile Section(IPS) and Out-of Pile System(OPS). The IPS, which is located inside the pool is divided into 3-parts; the in-pool pipes, the IVA(IPS Vessel Assembly) and the support structures. The test fuel is loaded inside a double wall, inner pressure vessel and outer pressure vessel, to keep the functionality of the reactor coolant pressure boundary. The IVA is manufactured by local company and the functional test and verification were done through pressure drop, vibration, hydraulic and leakage tests. The brazing technique for the instrument lines has been checked for its functionality and performance. An IVA has been manufactured by local technique and have finally tested under high temperature and high pressure. The IVA and piping did not experience leakage, as we have checked the piping, flanges, assembly parts. We have obtained good data during the three cycle test which includes a pressure test, pressure and temperature cycling, and constant temperature.