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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 27, Issue 12 - Dec 2003
Volume 27, Issue 11 - Nov 2003
Volume 27, Issue 10 - Oct 2003
Volume 27, Issue 9 - Sep 2003
Volume 27, Issue 8 - Aug 2003
Volume 27, Issue 7 - Jul 2003
Volume 27, Issue 6 - Jun 2003
Volume 27, Issue 5 - May 2003
Volume 27, Issue 4 - Apr 2003
Volume 27, Issue 3 - Mar 2003
Volume 27, Issue 2 - Feb 2003
Volume 27, Issue 1 - Jan 2003
Selecting the target year
The Strength Properties of Metal Matrix Composites by Binder Additives
Park, Won-Jo ; Huh, Sun-Chul ;
Transactions of the Korean Society of Mechanical Engineers A, volume 27, issue 7, 2003, Pages 1051~1057
DOI : 10.3795/KSME-A.2003.27.7.1051
This study is about controlled impurities, which make metal alloys, especially AC4CH alloy that is made by restraining 0.2％ Fe and Aluminum to make a matrix material. A metal matrix composite is produced using the squeeze casting method. The first step in the squeeze casting method is to add some organic binder including aluminum borate whisker into the matrix. After the fabrication of a metal matrix composite, each is individually appended to an inanimate binder such as SiO
, and TiO
. Through experiments the mechanical property changes were investigated between the metal matrix composite and AC4CH alloy. This study proves the superiority of the mechanical property of a metal matrix composites over AC4CH according to the previous tests and results that were mentioned above. One excellent property of matrix material composites is the infiltrated TiO
reinforcement. This material is a good substitute for the existing materials that are used in the development of industries today.
Noise Estimation of Oil Lubricated Journal Bearings
Rho, Byoung-Hoo ; Kim, Kyung-Woong ;
Transactions of the Korean Society of Mechanical Engineers A, volume 27, issue 7, 2003, Pages 1058~1064
DOI : 10.3795/KSME-A.2003.27.7.1058
Noise estimating procedures of oil lubricated journal bearings are presented. Nonlinear analysis of rotor-bearing system including unbalance mass of the rotor is performed in order to obtain acoustical properties of the bearing. Acoustical properties of the bearing are investigated through frequency analysis of the pressure fluctuation of the fluid film calculated from the nonlinear analysis. Noise estimating procedures presented in this paper could aid in the evaluation and understanding of acoustical properties of oil lubricated journal bearings.
A Study on the Calculating Method of the Heat Input Efficiency in Arcspot Welding
Jang, Kyoung-Bok ; Cho, Sang-Myoung ;
Transactions of the Korean Society of Mechanical Engineers A, volume 27, issue 7, 2003, Pages 1065~1070
DOI : 10.3795/KSME-A.2003.27.7.1065
In arc spot welding process, the arc is not moving and heat input is concentrated in one spot so that the heat input efficiency of arc is higher than that of GMAW. In other words, the heat input efficiency of arc change during weld time because arc start is done in spot and weld metal is filled. Therefore, the heat input model of arc spot welding should be different from that of general GMAW. In present study, the calculating model of heat input efficiency in arc spot welding was suggested by temperature monitoring near spot in arc spot welding of copper plate. The result showed that the heat input efficiency of arc was changed three times during weld time. The accuracy of calculating method of heat input efficiency was verified by heat transfer analysis of arc spot welding process using finite element method.
Micromachined DNA Manipulation Device Using Circular Multi-Electrodes
Moon, Sang-Jun ; Yun, Jae-Young ; Lee, Seung-S. ; Nam, Hong-Kil ; Chi, Yeun-Tae ;
Transactions of the Korean Society of Mechanical Engineers A, volume 27, issue 7, 2003, Pages 1071~1075
DOI : 10.3795/KSME-A.2003.27.7.1071
In this paper, we present a DNA manipulation device in the reaction chamber, which consists of a center electrode and circular outer electrodes of a reaction unit. The charged bio-molecules, DNA, are manipulated by the charge of the electrode in reaction unit. Controlling the induced dynamic electric field between the center electrode and the outer electrodes, concentration / repulsion / manipulation of bio-molecules are enabled at a periphery of electrode. Concentration of the fluorescent DNA at the center electrode is observed by applying ＋2V. Subsequently, applying －2V, the concentrated DNA is repelled rapidly from the center electrode, which makes dispersion completely in 0.5second. Furthermore, repeated applying ＋1V/－1V every 5 seconds at each outer electrode, we can circulate the DNA. We also investigate a micro-heater and sensor for DNA manipulation and reaction temperature. The coefficient of heat-resistance and heater temperature characteristic is 0.0043 and 100
Rubber Isostatic Pressing and Cold Isostatic Pressing of Metal Powder
Kim, Jong-Kwang ; Yang, Hoon-Chul ; Kim, Ki-Tae ;
Transactions of the Korean Society of Mechanical Engineers A, volume 27, issue 7, 2003, Pages 1076~1086
DOI : 10.3795/KSME-A.2003.27.7.1076
The effect of a rubber mould on densification behavior of aluminum alloy powder was investigated under cold isostatic compaction. A thickness of rubber mould and friction effect between die wall and rubber mould were also studied. The hyperelastic constitutive equation based on the Ogden strain energy potential was employed to analyze deformation of rubber. The elastoplastic constitutive equation of Shima and Oyane and that of Lee on densification were implemented into a finite element program (ABAQUS) to simulate densification of metal powder for cold isostatic pressing and rubber isostatic pressing. Finite element results were compared with experimental data for densification and deformation of aluminum alloy powder under isostatic compaction.
Finite Element Analysis of Piston Slap Phenomenon in Reciprocating Compressors Considering Coolant Circulation
Moon, Seung-Ju ; Cho, Jin-Rae ; Kim, Hyun-Ok ;
Transactions of the Korean Society of Mechanical Engineers A, volume 27, issue 7, 2003, Pages 1087~1094
DOI : 10.3795/KSME-A.2003.27.7.1087
The piston slap phenomenon occurs when the piston collides with the internal wall of the cylinder. Impact force caused by piston slap is one of the major mechanical noise sources in reciprocating compressors. In response to public demand, strict regulations are increasingly being imposed on the allowable noise level which is caused mostly by household electric appliances. In this paper, forces acting on piston by considering the dynamic behavior of suction and discharge valves are analytically calculated and the piston slap caused by the piston secondary motion is investigated by the finite element method.
Development of Calibrating Instrument for Tool Wear using Spindle Orientation Function in End Milling
Kim, Jeon-Ha ; Kang, Myung-Chang ; Kim, Jeong-Suk ; Kim, Kwang-Ho ;
Transactions of the Korean Society of Mechanical Engineers A, volume 27, issue 7, 2003, Pages 1095~1102
DOI : 10.3795/KSME-A.2003.27.7.1095
The most important thing in measuring the tool wear is to set up the measurement base. The end mill that is being used for machining of die is difficult to set up the base and to measure the tool wear because of geometric properties of that such as a helix and relief angle. In this study, a new instrument using spindle orientation function in end milling is developed to measure the tool wear and evaluated by the measuring system on the machine. Finally, this new method makes possible the wear measurement of same position and reduces the measuring time compared with the measuring methods such as the microscope and CCD.
A Study of Adaptive Bone Remodeling by Cellular Automata Method
Moon, Byung-Young ; Park, Jung-Hong ; Son, Kwon ;
Transactions of the Korean Society of Mechanical Engineers A, volume 27, issue 7, 2003, Pages 1103~1109
DOI : 10.3795/KSME-A.2003.27.7.1103
An adaptive bone remodeling is simulated by using the cellular automata (CA) method. It is assumed that bone tissue consist of bone marrow, osteoclast, osteoblast cell or osteoprogenitor cell. Two types of local rule are adopted; those are the metabolism rule and adaptive bone formation rule. The metabolism rule is based on the interactions of cells and the bone formation rule is based on the adaptation against the mechanical stimulus. The history of load and memory of mechanical stimulus are also considered in the local rules. As a result, the pattern of distribution of the bone tissue is dynamically adequate and it is similar to intact cancellous bone.
3D Grasp Planning using Stereo Matching and Neural Network
Lee, Hyun-Ki ; Bae, Joon-Young ; Lee, Sang-Ryong ;
Transactions of the Korean Society of Mechanical Engineers A, volume 27, issue 7, 2003, Pages 1110~1119
DOI : 10.3795/KSME-A.2003.27.7.1110
This paper deals with the synthesis of the 3-dimensional grasp planning for unknown objects. Previous studies have many problems, which the estimation time for finding the grasping points is much long and the analysis used the not-perfect 3-dimensional modeling. To overcome these limitations in this paper new algorithm is proposed, which algorithm is achieved by two steps. First step is to find the whole 3-dimensional geometrical modeling for unknown objects by using stereo matching. Second step is to find the optimal grasping points for unknown objects by using the neural network trained by the result of optimization using genetic algorithm. The algorithm is verified by computer simulation, comparing the result between neural network and optimization.
Calculation of Stress Intensity Factors Using the Mixed Volume and Boundary Integral Equation Method
Lee, Jung-Ki ; Lee, Hyeong-Min ;
Transactions of the Korean Society of Mechanical Engineers A, volume 27, issue 7, 2003, Pages 1120~1131
DOI : 10.3795/KSME-A.2003.27.7.1120
A recently developed numerical method based on a mixed volume and boundary integral equation method is applied to calculate the accurate stress intensity factors at the crack tips in unbounded isotropic solids in the presence of multiple anisotropic inclusions and cracks subject to external loads. Firstly, it should be noted that this newly developed numerical method does not require the Green's function for anisotropic inclusions to solve this class of problems since only Green's function for the unbounded isotropic matrix is involved in their formulation for the analysis. Secondly, this method takes full advantage of the capabilities developed in FEM and BIEM. In this paper, a detailed analysis of the stress intensity factors are carried out for an unbounded isotropic matrix containing an orthotropic cylindrical inclusion and a crack. The accuracy and effectiveness of the new method are examined through comparison with results obtained from analytical method and volume integral equation method. It is demonstrated that this new method is very accurate and effective for solving plane elastostatic problems in unbounded solids containing anisotropic inclusions and cracks.
Interfacial Moderation and Characterization of Nb/MoSi
Lee, Sang-Pill ; Yoon, Han-Ki ;
Transactions of the Korean Society of Mechanical Engineers A, volume 27, issue 7, 2003, Pages 1132~1137
DOI : 10.3795/KSME-A.2003.27.7.1132
This study dealt with the suppression of interfacial reaction between Nb and MoSi
for the fabrication of high toughness Nb/MoSi
laminate composites, based on the results of a thermodynamical estimation. Especially, the effect of ZrO
particle on the interfacial reaction of Nb/MoSi
bonding materials has been examined. Nb/MoSi
bonding materials have been successfully fabricated by alternatively stacking matrix mixtures and Nb sheets and hot pressing in the graphite mould. The addition of ZrO
particle to MoSi
matrix is obviously effective for promoting both the interfacial reaction suppression and the sintered density of Nb/MoSi
bonding materials, since it is caused by the formation of ZrSiO
in the MoSi
matrix mixture. The interfacial shear strength of Nb/MoSi
bonding materials also decreases with the reduction of interfacial reaction layer associated with the content of ZrO
particle and the fabrication temperature.
Analysis of the Dynamic Behavior and Lubrication Characteristics of a Small Reciprocating Compressor
Kim, Tae-Jong ;
Transactions of the Korean Society of Mechanical Engineers A, volume 27, issue 7, 2003, Pages 1138~1145
DOI : 10.3795/KSME-A.2003.27.7.1138
In this paper, a study on the dynamic behavior and lubrication characteristics of a reciprocating compression mechanism used in small refrigeration compressor is performed. In the problem formulation of the compressor dynamics, the viscous frictional force between piston and cylinder wall is considered in order to determine the coupled dynamic behaviors of piston and crankshaft. The solutions of the equations of motion of the reciprocating mechanism along with the time dependent Reynolds equations for the lubricating film between piston and cylinder wall and oil films of the journal bearings are obtained simultaneously. The hydrodynamic forces of journal bearings are calculated using finite bearing model and Gumbel boundary condition. And, a Newton-Raphson procedure was employed in solving the nonlinear equations of piston and crankshaft. The results explored the effects of design parameters on the stability and lubrication characteristics of the compression mechanism.
Driver Adaptive Control Algorithm for Intelligent Vehicle
Min, Suk-Ki ; Yi, Kyong-Su ;
Transactions of the Korean Society of Mechanical Engineers A, volume 27, issue 7, 2003, Pages 1146~1151
DOI : 10.3795/KSME-A.2003.27.7.1146
In this paper, results of an analysis of driving behavior characteristics and a driver-adaptive control algorithm for adaptive cruise control systems have been described. The analysis has been performed based on real-world driving data. The vehicle longitudinal control algorithm developed in our previous research has been extended based on the analysis to incorporate the driving characteristics of the human drivers into the control algorithm and to achieve natural vehicle behavior of the adaptive cruise controlled vehicle that would feel comfortable to the human driver. A driving characteristic parameters estimation algorithm has been developed. The driving characteristics parameters of a human driver have been estimated during manual driving using the recursive least-square algorithm and then the estimated ones have been used in the controller adaptation. The vehicle following characteristics of the adaptive cruise control vehicles with and without the driving behavior parameter estimation algorithm have been compared to those of the manual driving. It has been shown that the vehicle following behavior of the controlled vehicle with the adaptive control algorithm is quite close to that of the human controlled vehicles. Therefore, it can be expected that the more natural and more comfortable vehicle behavior would be achieved by the use of the driver adaptive cruise control algorithm.
Temperature Dependence of Dynamic Behavior of Commercially Pure Titanium by the Compression Test
Lee, Su-Min ; Seo, Song-Won ; Park, Kyoung-Joon ; Min, Oak-Key ;
Transactions of the Korean Society of Mechanical Engineers A, volume 27, issue 7, 2003, Pages 1152~1158
DOI : 10.3795/KSME-A.2003.27.7.1152
The mechanical behavior of a commercially pure titanium (CP-Ti) is investigated at high temperature Split Hopkinson Pressure Bar (SHPB) compression test with high strain-rate. Tests are performed over a temperature range from room temperature to 1000
with interval of 200
and a strain-rate range of 1900 ∼ 2000/sec. The true flow stress-true strain relations depending on temperature are achieved in these tests. For construction of constitutive equation from the true flow stress-true strain relation, parameters for the Johnson-Cook constitutive equation is determined. And the modified Johnson-Cook equation is used for investigation of behavior of flow stress in vicinity of recrystalization temperature. The Modified Johnson-Cook constitutive equation is more suitable in expressing the dynamic behavior of a CP-Ti at high temperature, i.e. about recrystalization temperature.
Interfacial Crack-tip Constraints and J-integrals in Plastically Hardening Bimaterials under Full Yielding
Lee, Hyung-Yil ; Kim, Yong-Bom ;
Transactions of the Korean Society of Mechanical Engineers A, volume 27, issue 7, 2003, Pages 1159~1169
DOI : 10.3795/KSME-A.2003.27.7.1159
This paper investigates the effects of T-stress and plastic hardening mismatch on the interfacial crack-tip stress field via finite element analyses. Plane strain elastic-plastic crack-tip fields are modeled with both MBL formulation and a full SEC specimen under pure bending. Modified Prandtl slip line fields illustrate the effects of T-stress on crack-tip constraint in homogeneous material. Compressive T-stress substantially reduces the interfacial crack-tip constraint, but increases the J-contribution by lower hardening material, J
L/. For bimaterials with two elastic-plastic materials, increasing plastic hardening mismatch increases both crack-tip stress constraint in the lower hardening material and J
L/. The fracture toughness for bimaterial joints would consequently be much lower than that of lower hardening homogeneous material. The implication of unbalanced J-integral in bimaterials is also discussed.
Elastic-Plastic J Estimations for Pipes with Off-Centred Circumferential Through-Wall Cracks
Shim, Do-Jun ; Huh, Nam-Su ; Kim, Yun-Jae ; Kim, Young-Jin ;
Transactions of the Korean Society of Mechanical Engineers A, volume 27, issue 7, 2003, Pages 1170~1178
DOI : 10.3795/KSME-A.2003.27.7.1170
This paper provides approximate J estimates for off-centred, circumferential through-wall cracks in cylinders under bending and under combined tension and bending. The proposed method is based on the reference stress approach, where the dependence of elastic and plastic influence functions of J on the cylinder/crack geometry, the off-centred angle and strain hardening is minimised through the use of a proper normalising load. Based on published limited FE results for off-centred, circumferential through-wall cracks under bending, such normalising load is found, based on which the reference stress based J estimates are proposed for more general cases, such as for a different cylinder geometry and for combined loading. Comparison of the estimated J with extensive FE J results shows overall good agreements for different crack/cylinder geometries and for combined tension and bending, which provides sufficient confidence in the use of the proposed method to fracture mechanics analyses of off-centred circumferential cracks. Furthermore, the proposed method is simple to use, giving significant merits in practice.
An Experimental Study on the Tappet Spin for a Direct Acting Valve Train System
Cho, Myung-Rae ; Kim, Hyung-Jun ; Moon, Tae-Seon ; Han, Dong-Chul ;
Transactions of the Korean Society of Mechanical Engineers A, volume 27, issue 7, 2003, Pages 1179~1184
DOI : 10.3795/KSME-A.2003.27.7.1179
The technique for measuring the rotational speed of tappet in direct acting type valve train system has been developed. The optic signal monitoring system with laser and optic fiber was designed to follow the signal of tappet rotation. The system was based on ON/OFF signal generation from the additional encoder teeth under the tappet with optic fibers attached photo transistor. The data showed that tappet rotation was affected by offset, oil temperature and cam shaft operating speed. Also it was found that tappet rotation increases with oil temperature. Tappet spin was delayed 10∼s20
cam angle after valve opening. The instantaneous rotational speed of tappet was reciprocal to cam shaft speed and the tappet and the cam angle ratio was located in the range of 0.1∼0.3.
Prediction of Initiation Location and Direction of Fretting Fatigue Crack
Huh, Yong-Hak ; R. E. Edwards ; M.W. Brown ; E.R. de Ios Rios ;
Transactions of the Korean Society of Mechanical Engineers A, volume 27, issue 7, 2003, Pages 1185~1192
DOI : 10.3795/KSME-A.2003.27.7.1185
Governing parameters for determination of the location of crack initiation and direction of crack initiation were investigated by performing fretting fatigue tests and analysis on Al 2024-T351. Fatigue tests were carried out using biaxial fatigue machine. It was shown that the dominant fatigue crack tended to initiate at the outer edge of one of the four bridge pads, growing at an angle beneath a pad, before turning perpendicular to the orientation of the axial load. Distribution of stresses generated during fretting fatigue loading along the interface was calculated by elastic FE simulation. It can be known that the location of crack initiation can be predicted by using the maximum tangential stress range. Futhermore, the crack initiation direction can also be predicted by a maximum tangential stress range.
Experimental Study on Dynamic Track Tensioning System in Tracked Vehicles
Suh, Mun-Suk ; Kim, Jae-Yong ; Jeong, Soon-Kyu ; Huh, Kun-Soo ; Kim, Il-Min ; Chung, Chung-Choo ; Choi, Jae-Mo ;
Transactions of the Korean Society of Mechanical Engineers A, volume 27, issue 7, 2003, Pages 1193~1199
DOI : 10.3795/KSME-A.2003.27.7.1193
Maintaining track tension in tracked vehicles minimizes the excessive load on the tracks and prevents the peal-off of tracks from the road-wheel, and adequately guarantees the stable and improved driving of the tracked vehicles. However, the track tension cannot be easily measured due to the limitation in the sensor technology, harsh environment, etc. In this study, the track tension is estimated in realtime from the measurable signals of tracked vehicles and controlled based on a fuzzy logic controller. The proposed control system is implemented on tracked vehicles and its performance is evaluated under various driving conditions.
Development of Assessment Methodology for Locally Corroded Pipe Using Reference Stress Concept
Lim, Hwan ; Shim, Do-Jun ; Kim, Yun-Jae ; Kim, Young-Jin ;
Transactions of the Korean Society of Mechanical Engineers A, volume 27, issue 7, 2003, Pages 1200~1209
DOI : 10.3795/KSME-A.2003.27.7.1200
In this paper, a unified methodology based on the local stress concept to estimate residual strength of locally thinned pipes. An underlying idea of the proposed methodology is that the local stress in the minimum section for locally thinned pipe is related to the reference stress, popularly used in creep problems. Then the problem remains how to define the reference stress, that is the reference load. Extensive three-dimensional finite element (FE) analyses were performed to simulate full-scale pipe tests conducted for various shapes of wall thinned area under internal pressure and bending moment. Based on these FE results, the reference load is proposed, which is independent of materials. A natural outcome of this method is the maximum load capacity. By comparing with existing test results, it is shown that the reference stress is related to the fracture stress, which in turn can be posed as the fracture criterion of locally thinned pipes. The proposed method is powerful as it can be easily generalised to more complex problems, such as pipe bends and tee-joints.
Topology Design of a Structure with a Specified Eigenfrequency
Lee, Jong-Hwan ; Min, Seung-Jae ;
Transactions of the Korean Society of Mechanical Engineers A, volume 27, issue 7, 2003, Pages 1210~1216
DOI : 10.3795/KSME-A.2003.27.7.1210
Topology optimization is applied to determine the layout of a structural component with a specified frequency by minimizing the difference between the specified structural frequency and a given frequency. The homogenization design method is employed and the topology design problem is solved by the optimality criteria method. The value of a weighting factor in the optimality criteria plays an important role in this topology design problem. The modified optimality criteria method approximated by using the binomial expansion is suggested to determine the suitable value of the weighting factor, which makes convergence stable. If a given frequency is set as an excited frequency, it is possible to avoid resonance by moving away the specified structural frequency from the given frequency. The results of several test problems are compared with previous works and show the validity of the proposed algorithm.
An Experimental Study on the Fatigue Crack Propagation Behavior in CTS Specimen under Mode II Loading
Song, Sam-Hong ; Lee, Jeong-Moo ;
Transactions of the Korean Society of Mechanical Engineers A, volume 27, issue 7, 2003, Pages 1217~1226
DOI : 10.3795/KSME-A.2003.27.7.1217
The purpose of this paper is to investigate fatigue crack behavior under shear(Mode II) loading. Various specimens and devices have been used in order to produce Mode II loading in fatigue experiments for shear crack propagation. But, there is not sufficient comparisons of experimental results between Mode II and others loading modes, because of characteristics of applied loads and specimens. So, compact tension shear(CTS) specimens were used in this paper to investigate the propagation behavior of Mode II by comparing the experimental results between loading modes. We firstly observed the characteristics which was showed in Mode II experiment using CTS specimens. The experimental results under Mode II loading were compared with fatigue crack behavior under Mode I and Mixed-mode I＋II loading. The characteristics for initiation and propagation behavior under Mode II loading was investigated by such comparisons.
NURBS Post-Processing of Linear Tool Path
Kim, Su-Jin ; Choi, In-Hugh ; Yang, Min-Yang ;
Transactions of the Korean Society of Mechanical Engineers A, volume 27, issue 7, 2003, Pages 1227~1233
DOI : 10.3795/KSME-A.2003.27.7.1227
NURBS (Non Uniform Rational B-Spline) is widely used in CAD system and NC data for high speed machining. Conventional CAM system changes NURBS surface to tessellated meshes or Z-map model, and produces linear tool path. The linear tool path is not good fur precise machining and high speed machining. In this paper, an algorithm to change linear tool path to NURBS one was studied and the machining result of NURBS tool path was compared with that of linear tool path. The N-post including both a post-processing and a virtual machining software was developed. The N-Post transforms linear tool path to NURBS tool path and quickly shades a machined product on OpenGL view, while comparing a machined surface with a original CAD one. A virtulal machined model of original tool path and post-processed tool path was compared to original CAD model. The machining error and machining time of post-processed NURBS tool path were investigated.
Gradient Index Based Robust Optimal Design Method for MEMS Structures
Han, Jeung-Sam ; Kwak, Byung-Man ;
Transactions of the Korean Society of Mechanical Engineers A, volume 27, issue 7, 2003, Pages 1234~1242
DOI : 10.3795/KSME-A.2003.27.7.1234
In this paper we present a simple and efficient robust optimal design formulation for MEMS structures and its application to a resonant-type micro probe. The basic idea is to use the gradient index (GI) to improve robustness of the objective and constraint functions. In the robust optimal design procedure, a deterministic optimization for performance of MEMS structures is followed by design sensitivity analysis with respect to uncertainties such as fabrication errors and change of operating conditions. During the process of deterministic optimization and sensitivity analysis, dominant performance and uncertain variables are identified to define GI. The GI is incorporated as a term of objective and constraint functions in the robust optimal design formulation to make both performance and robustness improved. While most previous approaches for robust optimal design require statistical information on design variations, the proposed GI based method needs no such information and therefore is cost-effective and easily applicable to early design stages. For the micro probe example, robust optimums are obtained to satisfy the targets for the measurement sensitivity and they are compared in terms of robustness and production yield with the deterministic optimums through the Monte Carlo simulation. This method, although shown for MEMS structures, may as well be easily applied to conventional mechanical structures where information on uncertainties is lacking but robustness is highly important.
FE Analysis of Hot Forging Process and Microstructure Prediction for Lower Arm Connector
Park, Jong-Jin ; Hwang, Han-Sub ; Lee, Sang-Joo ; Hong, Seung-Chan ; Lim, Sung-Hwan ; Lee, Kyung-Sub ; Lee, Kyung-Jong ;
Transactions of the Korean Society of Mechanical Engineers A, volume 27, issue 7, 2003, Pages 1243~1250
DOI : 10.3795/KSME-A.2003.27.7.1243
In the present study, hot forging process for a lower arm connector of an automobile was investigated. An FEM code, DEFORM-3D, was used to analyze the process and the process parameters, such as temperature, strain and strain rate, were obtained. The microstructure of the connector was predicted by applying the Sellars and Yada microstructure evolution models to the process parameters. The method of microstructure prediction used in the present study seems to be effective for the quality assurance of a forged automotive product.