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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 29, Issue 12 - Dec 2005
Volume 29, Issue 11 - Nov 2005
Volume 29, Issue 10 - Oct 2005
Volume 29, Issue 9 - Sep 2005
Volume 29, Issue 8 - Aug 2005
Volume 29, Issue 7 - Jul 2005
Volume 29, Issue 6 - Jun 2005
Volume 29, Issue 5 - May 2005
Volume 29, Issue 4 - Apr 2005
Volume 29, Issue 3 - Mar 2005
Volume 29, Issue 2 - Feb 2005
Volume 29, Issue 1 - Jan 2005
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Analysis on LGP with Multi-Side-Lamp
Park Jong-Ryul ; Sah Jong-Youb ;
Transactions of the Korean Society of Mechanical Engineers A, volume 29, issue 3, 2005, Pages 361~368
DOI : 10.3795/KSME-A.2005.29.3.361
LGP(Light-Guide Panel) of LCD backlight is one of the major componets which affect on the product quality of LCD. The LGP with multi-side lamp has been analized for pattern design with the uniform distribution of brightness. When given the uniform distribution of brightness as target, the distribution of dot pattern has been designed for superposed distributions of brightness for each lamp. Multi-side lamp has been tested for various types such as ㄴ-, ㄷ-, and ㅁ -shapes. The present study enhances the possibility of LGP with multi-side lamp by showing the pricise control of brightness distribution.
An Overview of Optimization of Structures Subjected to Transient Loads
Park Gyung-Jin ; Kang Byung-Soo ;
Transactions of the Korean Society of Mechanical Engineers A, volume 29, issue 3, 2005, Pages 369~386
DOI : 10.3795/KSME-A.2005.29.3.369
Various aspects of structural optimization techniques under transient loads are extensively reviewed. The main themes of the paper are treatment of time dependent constraints, calculation of design sensitivity, and approximation. Each subject is reviewed with the corresponding papers that have been published since 1970s. The treatment of time dependent constraints in both the direct method and the transformation method is discussed. Two ways of calculating design sensitivity of a structure under transient loads are discussed - direct differentiation method and adjoint variable method. The approximation concept mainly focuses on re- sponse surface method in crashworthiness and local approximation with the intermediate variable Especially, as an approximated optimization technique, Equivalent Static Load method which takes advantage of the well-established static response optimization technique is introduced. And as an application area of dynamic response optimization technique, the structural optimization in flexible multibody dynamic systems is re- viewed in the viewpoint of the above three themes
Model Validation for the CBS Ku-Band Transponder Panel Using Launch Environmental Test
Seo Hyun Suk ; Choi Jang Sub ; Park Jong Heung ; Woo Hyung Je ;
Transactions of the Korean Society of Mechanical Engineers A, volume 29, issue 3, 2005, Pages 387~394
DOI : 10.3795/KSME-A.2005.29.3.387
Accurate predictions and simulations of the behavior of space structures based on analytical models become more important. In order to perform analysis to support the design of Ku-band transponder panel for the Communications and Broadcasting Satellite(CBS), mathematical models of the panel were generated in the form of finite element models. Test verification of these models is required before the transponder panel can be certified for launch environments. A modal identification was performed to obtain modal parameters which can be compared with the test results using correlation techniques. This paper approaches the sensor placement from the standpoint of the structural dynamicist who uses the modal parameter obtained during launch environmental test. The models were validated by performing a test-analysis correlation and updating analysis. It was proved that the Ku-band transponder panel satisfies the environmental test requirements.
Application of a Multidisciplinary Design Optimization Algorithm to Design of a Belt Integrated Seat Considering Crashworthiness
Shin Moon-Kyun ; Kang Byung-Soo ; Park Gyung-Jin ;
Transactions of the Korean Society of Mechanical Engineers A, volume 29, issue 3, 2005, Pages 395~402
DOI : 10.3795/KSME-A.2005.29.3.395
Recently Multidisciplinary Design Optimization Based on Independent Subspaces (MDOIS), an MDO (multidisciplinary design optimization) algorithm, has been proposed. In this research, an MDO problem is defined for design of a belt integrated seat considering crashworthiness, and MDOIS is applied to solve the problem. The crash model consists of an airbag, a belt integrated seat (BIS), an energy absorbing steering system, and a safety belt. It is found that the current design problem has two disciplines - structural nonlin- ear analysis and occupant analysis. The interdisciplinary relationship between the disciplines is identified and is addressed in the system analysis step in MDOIS. Interdisciplinary variables are belt load and stiffness of the seat, which are determined in system analysis step. The belt load is passed to the structural analysis subspace and stiffness of the seat back frame to the occupant analysis subspace. Determined design vari- ables in each subspace are passed to the system analysis step. In this way, the design process iterates until the convergence criterion is satisfied. As a result of the design, the weight of the BIS and Head Injury Crite- rion (HIC) of an occupant are reduced with specified constraints satisfied at the same time. Since the system analysis cannot be formulated in an explicit form in the current example, an optimization problem is formu - lated to solve the system analysis. The results from MDOIS are discussed.
Benchmarking of Design Optimization Frameworks In View of Excel Interface
Yum Keun-Chul ; Lee Se Jung ;
Transactions of the Korean Society of Mechanical Engineers A, volume 29, issue 3, 2005, Pages 403~410
DOI : 10.3795/KSME-A.2005.29.3.403
This study presents the benchmark results of several design frameworks for the purpose of developing an efficient design framework in view of Excel interface. For the benchmark, three optimum design problems are chosen and solved by using the design frameworks. In order to compare the frameworks with each other, the evaluation criteria are specified and modified to fit the problems with Excel interface. Three example cases are solved and compared. The evaluation report is summarized in terms of efficiency, ease of use, internal structure, API, etc. However, the optimization result itself is not focused because the specific optimization algorithm is not our concern. Finally, some suggestions of how to develop an efficient design framework with Excel interface are presented.
Friction Characteristics for Density of Micro Dimples Using Photolithography
Kim Seock-sam ; Chae Young-hun ;
Transactions of the Korean Society of Mechanical Engineers A, volume 29, issue 3, 2005, Pages 411~417
DOI : 10.3795/KSME-A.2005.29.3.411
Surface texturing of tribological application is another attractive technology of friction reducing. Also, reduction of friction is therefore considered to be a necessary requirement for improved efficiency of machine. In this paper attempts to investigate the effect of density for micro-scale dimple pattern using photolithography on bearing steel flat mated with pin-on-disk. We demonstrated the lubrication mechanism for a Stribeck curve, which has a relationship between the friction coefficient and a dimensionless parameter for lubrication condition. It is found that friction coefficient is depended on the density of surface pattern. It was thus verified that micro-scale dimple could affect the friction reduction considerably under mixed and hydrodynamic lubrication conditions from based on friction map. Lubrication condition regime has an influence on the friction coefficient induced the density of micro dimple.
Design Parameters and Experimental Performance Evaluation of 4-bit Digital Multi-heater Microinjector
Kang Tae Goo ; Cho Young-Ho ;
Transactions of the Korean Society of Mechanical Engineers A, volume 29, issue 3, 2005, Pages 418~424
DOI : 10.3795/KSME-A.2005.29.3.418
We present the design, fabrication and experimental results of 4-bit digital microinjectors, whose ejected droplet volumes are adjusted by the digital operation of a 4-bit microheater array. We design the reference microinjectors as well as its comparative test structures. In the fabrication process, we use a five-mask micromachining process and the total chip size of the fabricated microinjector is
We measure the ejected droplet volumes and velocities, which are adjusted from
respectively, depending on the 15 possible combinations of 4-bit microheater array. We also experimentally characterize the effect of geometric variation including the microheater size, inter-microheater gap, microchannel width and sequential operation of microheater array on the ejected droplet volume and velocity. Among these parameters, we find that the microheater size is the most dominant parameter affected to the ejected droplet volumes and velocities. Thus, the present microinjector has a potential for application to the high-resolution inkjet printers with multiple gray levels or high-precision fluid injectors with variable volume control.
Fabrication of Reaction Sintered SiC Materials by Complex Slurry with Nano Size Particles
Lee Sang-Pill ;
Transactions of the Korean Society of Mechanical Engineers A, volume 29, issue 3, 2005, Pages 425~431
DOI : 10.3795/KSME-A.2005.29.3.425
The efficiency of complex slurry preparation route for developing the high performance SiC matrix of
composites has been investigated. The green bodies for RS-SiC materials prior to the infiltration of molten silicon were prepared with various C/SiC complex slurries, which associated with both the sizes of starting SiC particles and the blending conditions of starting SiC and C particles. The characterization of Rs-SiC materials was examined by means of SEM, EDS and three point bending test. Based on the mechanical property-microstructure correlation, the process optimization is also discussed. The flexural strength of Rs-SiC materials greatly depended on the content of residual Si. The decrease of starting SiC particle size in the C/SiC complex slurry was effective for improving the flexural strength of RS-SiC materials.
The Effects of Groove Dimensions of Pad on CMP Characteristics
Park Ki-Hyun ; Kim Hyoung-Jae ; Choi Jae-young ; Seo Heon-deok ; Jeong Hae-do ;
Transactions of the Korean Society of Mechanical Engineers A, volume 29, issue 3, 2005, Pages 432~438
DOI : 10.3795/KSME-A.2005.29.3.432
CMP characteristics such as material removal rate and edge effect were measured and investigated in accordance with pad grooving effect, groove width, depth and pitch. GSQ (Groove Stiffness Quotient) and GFQ (Groove Flow Quotient) were proposed to estimate pad grooving characteristics. GSQ is defined as groove depth(D) divided by pad thickness(T) and GFQ is defined as groove width(W) divided by groove pitch(P). As GFQ value increased, material removal rate increased some point but gradually saturated. It seems that material removal rate is not affected by each parameter respectively but by interaction of these parameters such as groove dimensions. In addition, an increase in GFQ and GSQ causes edge effect to be improved. Because, pad stiffness decreases as GSQ and GFQ increase. In conclusion, groove influences relative pad stiffness although original mechanical properties of pad are unchanged by grooving. Also, it affects the flow of slurry that has an effect on the lubrication regime and polishing results. The change of groove dimensions has influence on pad stiffness and slurry flow, so that polishing results such as removal rate and edge effect become changed.
Free Vibration Analysis of Combined Cylindrical Shells with an Annular Plate Considering Additional Deformations
Chung Kang ; Kim Young-Wann ;
Transactions of the Korean Society of Mechanical Engineers A, volume 29, issue 3, 2005, Pages 439~446
DOI : 10.3795/KSME-A.2005.29.3.439
The theoretical method is developed to investigate the vibration characteristics of the combined cylindrical shells with an annular plate joined to the shell at any arbitrary axial position. The structural rotational coupling between shell and plate is simulated using the rotational artificial spring. For the translational coupling, the continuity conditions for the displacements of shell and plate are used. For the uncoupled annular plate, the transverse motion is considered and the in-plane motions are not. And the additional transverse and in-plane motions of the coupled annular plate by shell deformation are considered in analysis. Theoretical formulations are based on Love's thin shell theory. The frequency equation of the combined shell with an annular plate is derived using the Rayleigh-Ritz approach. The effect of inner-to-outer radius ratio, axial position and thickness of annular plate on vibration characteristics of combined cylindrical shells is studied. To demonstrate the validity of present theoretical method, the finite element analysis is performed.
Incomplete 2-manifold Mesh Based Tool Path Generation
Lee Sung-gun ; Kim Su-jin ; Yang Min-yang ; Lee Dong-yoon ;
Transactions of the Korean Society of Mechanical Engineers A, volume 29, issue 3, 2005, Pages 447~454
DOI : 10.3795/KSME-A.2005.29.3.447
This paper presents a new paradigm for 3-axis tool path generation based on an incomplete 2-manifold mesh model, namely, an inexact polyhedron. When geometric data is transferred from one system to another system and tessellated for tool path generation, the model does not have any topological data between meshes and facets. In contrast to the existing polyhedral machining approach, the proposed method generates tool paths from an incomplete 2-manifold mesh model. In order to generate gouge-free tool paths, CL-meshes are generated by offsetting boundary edges, boundary vertices, and facets. The CL-meshes are sliced by machining planes and the calculated intersections are sorted, trimmed, and linked. The grid method is used to reduce the computing time when range searching problems arise. The method is fully implemented and verified by machining an incomplete 2-manifold mesh model.
Six Sigma Robust Design of Composite Hand for LCD Glass Transfer Robot
Nam Hyunwook ;
Transactions of the Korean Society of Mechanical Engineers A, volume 29, issue 3, 2005, Pages 455~461
DOI : 10.3795/KSME-A.2005.29.3.455
This research studied robust design of composite hand for LTR (LCD glass Transfer Robot).
DOE (Design of Experiment) was conducted to find out vital few Xs. 108 experiments were performed and their results were statistically analyzed. Pareto chart analysis shows that the geometric parameters (height and width of composite beam) are more important than material parameters
or stacking sequence angle. Also, the stacking sequence of mid-layer is more important than that of outer-layer. The main effect plots shows that the maximum deflection of LTR hand is minimized with increasing height, width of beam and layer thickness.
DOE was conducted to obtain RSM (Response Surface Method) equation. 25 experiments were conducted. The CCD (Central Composite Design) technique with four factors was used. The coefficient of determination
for the calculated RSM equation was 0.989. Optimum design was conducted using the RSM equation. Multi-island genetic algorithm was used to optimum design. Optimum values for beam height, beam width, layer thickness and beam length were 24.9mm, 186.6mnL 0.15mm and 2402.4mm respectively. An approximate value of 0.77mm in deflection was expected to be a maximum under the optimum conditions. Six sigma robust design was conducted to find out guideline for control range of design parameter. To acquire six sigma level reliability, the standard deviation of design parameter should be con trolled within
of average design value
Effect of Fully and Semi Austempering Treament on the Fatigue Properties of Ductile Cast Iron
Lim Bok-kyu ; Hwang Jung-gak ; Kim Dong-Youl ; Kim Min-gun ;
Transactions of the Korean Society of Mechanical Engineers A, volume 29, issue 3, 2005, Pages 462~469
DOI : 10.3795/KSME-A.2005.29.3.462
Single phase bainite structure which is obtained by the conventional austempering treatment reduces the ductility of ductile cast iron. Because of the reduction of ductility it is possible to worsen the fatigue properties. Therefore, semi austempered ductile iron which is treated from
is prepared to investigate the static strength and fatigue properties in comparison with fully austempered ductile iron (is treated from
). In spite of semi austempered ductile iron shows the
increase of ductility. Also, semi austempered ductile iron shows the higher fatigue limit and lower fatigue crack growth rate as compared with fully austempered ductile iron. By the fractographical analysis, it is revealed that the ferrite obtained by semi austempering process brings about the plastic deformation(ductile striation) of crack tip and gives the prior path of crack propagation. The relatively low crack growth rate in semi austempered specimen is caused by above fractographical reasons.
Compressive and Bending Behavior of Sandwich Panels with Octet Truss Core Fabricated from Wires
Lim Ji-Hyun ; Nah Seong-Jun ; Koo Man-Hoe ; Kang Ki-Ju ;
Transactions of the Korean Society of Mechanical Engineers A, volume 29, issue 3, 2005, Pages 470~476
DOI : 10.3795/KSME-A.2005.29.3.470
Ultra light metal structures have been studied for several years because of their superior specific stiffness, strength and potential of multi functions. Many studies have been focused on how to manufacture ultra light metal structures and optimize them. In this study, we introduced a new idea to make sandwich panels having octet truss cores. Wires bent in a shape of triangular wave were assembled to construct an Octet truss core and it was bonded with two face sheets to be a sandwich panel. The bending & compressive strength and stiffness were estimated through elementary mechanics for the sandwich specimens with two kinds of face sheets and the results were compared with the ones measured by experiments. Some aspects of assembling and mechanical behavior were discussed compared with Kagome core fabricated from wire, which had been introduced in the authors' previous work.
A Study on the Fatigue Strength Evaluation and Improvement of Marine Propeller Materials
Yoon Han-Yong ; Jung Ui-Jung ; Lim Myung-Hwan ;
Transactions of the Korean Society of Mechanical Engineers A, volume 29, issue 3, 2005, Pages 477~483
DOI : 10.3795/KSME-A.2005.29.3.477
A propeller has been considered as one of the most critical elements in propelling ships. However, only a little research on the marine propeller has been carried out. Furthermore, fractures of the propeller have been frequently caused by fatigue, but only tensile strength, yield strength and elongation are discussed in Register of Shipping. For the above reasons, we have evaluated strength properties of A1BC3 and HBsC1, both which have been used for the marine propeller by using air jet chisel and then, presented a method of improving the strength.
A Study of Selecting Material for Forming Analysis in Auto-Body Panel Stamping Process
Hwang Jae Sin ; Moon Won Sub ; Lee Chan Ho ; You Ho Young ; Jung Dong Won ;
Transactions of the Korean Society of Mechanical Engineers A, volume 29, issue 3, 2005, Pages 484~494
DOI : 10.3795/KSME-A.2005.29.3.484
Finite element method is very effective method to simulate the forming processes with good prediction of the deformation behaviour. For the finite element modeling of sheet mental forming the accurate tool model is required. Due to the geometrical complexity of real-size part stamping tools it is hard to make FE model for real-size auto-body stamping parts. In this paper, it was focussed on the drawability factors on auto-body panel stamping by AUTOFORM with using tool planing alloy to reduce law price as well as high precision from Design Optimization of die. According to this study, the results of simulation will give engineers good information to access the Design Optimization of die.
Reliability Analysis and Preventive Maintenance for Fatigue Life of End Beam for Uncovered Freight Car
Baek Seok Hem ; Jeon Joo Heon ; Lee Kyoung Young ; Cho Seok Swoo ; Joo Won Sik ;
Transactions of the Korean Society of Mechanical Engineers A, volume 29, issue 3, 2005, Pages 495~502
DOI : 10.3795/KSME-A.2005.29.3.495
Increased cumulative running times of railroad vehicle brings out such degradation as wear and fatigue. It doesn't adapt corrective maintenance which repairs a poor part after a trouble but use preventive maintenance which fixes a bad part before a trouble. There were a few researches for preventive maintenance such as inspect affairs and facilities management. They couldn't estimate the operation reliability on railroad vehicle. Therefore, this study proposes the preventive maintenance procedure that predict repair period of end beam fur uncovered freight car using reliability function and instantaneous failure rate on the basis of fatigue test and load history data.
Topology Optimization of Inner-Wall Stiffener for Critical Buckling Loads of Cylindrical Containers
Youn Sung-Kie ; Yeon Jeoung-Heum ; Chang Su-Young ; Yoo loon-Tae ; Seo Yu-Deok ;
Transactions of the Korean Society of Mechanical Engineers A, volume 29, issue 3, 2005, Pages 503~510
DOI : 10.3795/KSME-A.2005.29.3.503
In this paper, the topology optimization of inner-wall stiffener of cylindrical containers for the use as a rocket fuel tank is presented. Such structures for space mission should have high stiffness against the buck]ins while their weight should be maintained low from the viewpoint of cost and performance. Therefore, in the present work the reciprocal of critical buckling load is adopted as an objective function and the total mass of stiffener is constrained to a prescribed value. Due to the restriction of computational resources a section of cylindrical container is topologically optimized and this result is repeated to obtain the full design. Also, for manufacturability the concept of periodic topology pattern in design domain is newly introduced. In the numerical examples, the results by the proposed approach are investigated and compared with those of isogrid design.