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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 30, Issue 12 - Dec 2006
Volume 30, Issue 11 - Nov 2006
Volume 30, Issue 10 - Oct 2006
Volume 30, Issue 9 - Sep 2006
Volume 30, Issue 8 - Aug 2006
Volume 30, Issue 7 - Jul 2006
Volume 30, Issue 6 - Jun 2006
Volume 30, Issue 5 - May 2006
Volume 30, Issue 4 - Apr 2006
Volume 30, Issue 3 - Mar 2006
Volume 30, Issue 2 - Feb 2006
Volume 30, Issue 1 - Jan 2006
Selecting the target year
Control of Processing Conditions for Improvement of vibration Characteristics of Injection Molded Disk
Sin Hyo-Chol ; Nam Ji-Geun ;
Transactions of the Korean Society of Mechanical Engineers A, volume 30, issue 6, 2006, Pages 615~621
DOI : 10.3795/KSME-A.2006.30.6.615
Increased application of optical disks requires more improved dynamic stability of rotating disks. In this study, a new concept of controlling the processing conditions of injection molded disks was developed to improve vibration characteristics. The critical speed, which shows stiffness and dynamic stability of disk, is affected by the residual stress distribution; this varies as functions of distance from the gate and processing condition. The critical speed of disk was calculated with the initial stress taken into consideration, which was determined from injection molding simulation. Choosing melt temperature, mold temperature, filling speed and packing pressure as design parameters, critical speed is maximized with the method of response surface. It is shown that the stability of injection molded disk has been improved for the new condition obtained as a result of the study proposed.
A Magnetic Suspension Stage Based on the Switched Reluctance Propulsion Principle
Lee Sang-Heon ;
Transactions of the Korean Society of Mechanical Engineers A, volume 30, issue 6, 2006, Pages 622~630
DOI : 10.3795/KSME-A.2006.30.6.622
This paper is about the magnetic suspension stage based on the Switched Reluctance propulsion principle. Because the previous studies on contact-free stage adopted the Lorentz force for main force generation mechanism they have suffered from thermal problem deteriorating the precision. Thus, the magnetic suspension stage adopting SR principle which can achieve high force density is proposed. The main operating principle and structure for achieving high resolution and long travel range are represented. The magnetic force analysis of each actuator, providing back data for dynamic modeling and controller design are carried out. By conducting basic experiments, the feasibility of the proposed system is shown. In addition the problems which should be improved and their solutions are represented.
Modeling of a Pneumatic Cylinder Position Control System Considering Transfer Characteristics of a Transmission Line
Kang Bo-Sik ; Song Chang-Seop ; Ji Sang-Won ; Jang Ji-Seong ;
Transactions of the Korean Society of Mechanical Engineers A, volume 30, issue 6, 2006, Pages 631~636
DOI : 10.3795/KSME-A.2006.30.6.631
In this study, a model of pneumatic cylinder position control system considering dynamic characteristics of transmission line is proposed. The transfer characteristics of transmission line are assumed to be second order transfer function because the effect of resonance characteristics of transmission line under high frequency range can be neglected by the friction force and low pass characteristics of the pneumatic cylinder driving system. Therefore, the position control system including transmission line can be modeled by using a model of pneumatic cylinder driving system and the model of transmission line. The effectiveness of the proposed model is proved by comparison of simulation results using proposed model with experimental results.
In-situ Measurement of Plastic Zone Developed During Ductile Fracture Process
Back Jung-Hyun ; Kim Do-Hyung ; Kang Ki-Ju ;
Transactions of the Korean Society of Mechanical Engineers A, volume 30, issue 6, 2006, Pages 637~642
DOI : 10.3795/KSME-A.2006.30.6.637
A plastic zone size is regarded as a measure of material resistance, and also it determines the fracture behavior. The importance of estimating or measuring the plastic zone size cannot be too emphasized. In this article, SDSP(Stereo Digital Speckle Photography) is examined as a new techniques to measure the plastic zone developed in a ductile metal. This technique is simple, vibration free and non-contact, and measures simultaneously in-plane displacements as well as out-of plane displacements like the side necking. Experimental results for a CT specimen are presented to demonstrate the accuracy in comparison with those obtained by recrystallization technique and finite element analysis.
Locomotions of a Biped Robot: Static vs. Dynamic Gaits
Lim Seung-Chul ; Ko In-Hwan ;
Transactions of the Korean Society of Mechanical Engineers A, volume 30, issue 6, 2006, Pages 643~652
DOI : 10.3795/KSME-A.2006.30.6.643
This paper is concerned with computer simulations of a biped robot walking in static and dynamic gaits. To this end, a three-dimensional robot is considered possessing a torso and two identical legs of a typical design. For such limbs, a set of inverse kinematic solutions is analytically derived between the torso and the feet. Specific walking patterns are off-line generated meeting stability based on the VPCG or ZMP condition. Subsequently, to verify whether the robot can walk as planned in the presence of mass and ground effects, a multi-body dynamics CAE code has been applied to the resulting joint motions determined by inverse kinematics. As a result, the key parameters to successful gaits could be identified including inherent characteristics as well. Upon comparisons between the two types of gaits, dynamic gaits are concluded more desirable for larger humaniods.
Fabrication of Metallic Sandwich Plates with Inner Dimpled Shell Structure and Static Bending Test
Seong Dae-Yong ; Jung Chang-Gyun ; Yoon Seok-Joon ; Lee Sang-Hoon ; Ahn Dong-Gyu ; Yang Dong-Yol ;
Transactions of the Korean Society of Mechanical Engineers A, volume 30, issue 6, 2006, Pages 653~661
DOI : 10.3795/KSME-A.2006.30.6.653
Metallic sandwich plates with various inner cores have important new features with not only ultra-light material characteristics and load bearing function but also multifunctional characteristics. Because of production possibility on the large scale and a good geometric precision, sandwich plates with inner dimpled shell structure from a single material have advantages as compared with other solid sandwich plates. Inner dimpled shell structures can be fabricated with press or roll forming process, and then bonded with two face sheets by multi-point resistance welding or adhesive bonding. Elasto-plastic bending behavior of sandwich plates have been predicted analytically and measured. The measurements have shown that elastic perfectly plastic approximation can be conveniently employed with less than 10% error in elastic stiffness, collapse load, and energy absorption. The dominant collapse modes are face buckling and bonding failure after yielding. Sandwich plates with inner dimpled shell structure can absorb more energy than other types of sandwich plates during the bending behavior.
Performance Test and Finite Element Analysis of Pneumatic Muscle Actuator
Huh Shin ; Bae Sang-Kyu ; Kim Dong-Soo ; Kim Wan-Doo ; Hong Sung-In ;
Transactions of the Korean Society of Mechanical Engineers A, volume 30, issue 6, 2006, Pages 662~669
DOI : 10.3795/KSME-A.2006.30.6.662
The pneumatic muscle actuator consists of an air bellows tube with two end-flanges. The air bellows tube is made from rubber layers and flexible sheathing formed from nylon 6 fibers. This structure can be stretched or compressed to convert the radial expansive forces into contractile forces. We performed the finite element analysis and the performance test of pneumatic muscle actuator. Also, the pneumatic muscle actuator was manufactured and tested by home-made tester. The results of FEA was similar with performance test below the maximum error of 42 %.
Dynamic Material Property of the Sinter-Forged Cu-Cr Alloys with the Variation of Chrome Content
Song Jung-Han ; Huh Hoon ;
Transactions of the Korean Society of Mechanical Engineers A, volume 30, issue 6, 2006, Pages 670~677
DOI : 10.3795/KSME-A.2006.30.6.670
Vacuum interrupters are used in various switch-gear components such as circuit breakers, distribution switches, contactors. The electrodes of a vacuum interrupter are manufactured of sinter-forged Cu-Cr material for good electrical and mechanical characteristics. Since the closing velocity is 1-2m/s and impact deformation of the electrode depends on the strain-rate at the given velocity, the dynamic material property of the sinter-forged Cu-Cr alloy is important to design the vacuum interrupter reliably and to identify the impact characteristics of a vacuum interrupter accurately. This paper is concerned with the dynamic material properties of sinter-forged Cu-Cr alloy for various strain rates. The amount of chrome is varied from 10 wt% to 30 wt% in order to investigate the influence of the chrome content on the dynamic material property. The high speed tensile test machine is utilized in order to identify the dynamic property of the Cu-Cr alloy at the intermediate strain-rate and the split Hopkinson pressure bar is used at the high strain-rate. Experimental results from both the quasi-static and the high strain-rate up to the 5000/sec are interpolated with respect to the amount of chrome in order to construct the Johnson-Cook and the modified Johnson-Cook model as the constitutive relation that should be applied to numerical simulation of the impact behavior of electrodes.
5-Axis Tool Path Generation from Offset Polyhedral Mesh
Kim Su-Jin ; Yang Min-Yang ;
Transactions of the Korean Society of Mechanical Engineers A, volume 30, issue 6, 2006, Pages 678~683
DOI : 10.3795/KSME-A.2006.30.6.678
In this paper, the 5-axis tool path that has been generated from the original surface is, newly generated from the offset polyhedral mesh. In this approach, the interference check between two solid models can be simplified to that of offset polyhedral mesh and axis line. The tool path computation and interference check based on the offset mesh is simpler and faster than that based on the original surface. But 5-axis tool path generation using this approach is able to apply only for ball endmill and still takes longer time than 3-axis tool path generation.
Development of a Prototype New Electric Power Steering (EPS) System
Song Jeong-Hoon ;
Transactions of the Korean Society of Mechanical Engineers A, volume 30, issue 6, 2006, Pages 684~690
DOI : 10.3795/KSME-A.2006.30.6.684
This study proposes and validates a new column type electric power steering system (EPS-TT). It is driven by a uni-directional motor and two electro-magnetic clutches. The assist motor produces assist torque in only one direction and two clutches transmit the torque to the column of steering system in either left or right direction with respect to the steering input. A full order and a reduced order models are developed to evaluate the EPS-TT. Models are also used to investigate the vehicle responses. A PID control logic is designed to control the torque of the assist motor. A driver model is applied to the system and the resulting performances are analyzed. The results show that the performances of the full order model are similar to those of reduced order model. The results also prove that the performances achieved by the EPS-TT are improved compared to those of a conventional EPS-TT across the frequency domain.
Sequential Feasible Domain Sampling of Kriging Metamodel by Using Penalty Function
Lee Tae-Hee ; Seong Jun-Yeob ; Jung Jae-Jun ;
Transactions of the Korean Society of Mechanical Engineers A, volume 30, issue 6, 2006, Pages 691~697
DOI : 10.3795/KSME-A.2006.30.6.691
Metamodel, model of model, has been widely used to improve an efficiency of optimization process in engineering fields. However, global metamodels of constraints in a constrained optimization problem are required good accuracy around neighborhood of optimum point. To satisfy this requirement, more sampling points must be located around the boundary and inside of feasible region. Therefore, a new sampling strategy that is capable of identifying feasible domain should be applied to select sampling points for metamodels of constraints. In this research, we suggeste sequential feasible domain sampling that can locate sampling points likely within feasible domain by using penalty function method. To validate the excellence of feasible domain sampling, we compare the optimum results from the proposed method with those form conventional global space-filling sampling for a variety of optimization problems. The advantages of the feasible domain sampling are discussed further.
Electrode Shape Optimization of Piezo Sensors Using Genetic Algorithm
Lee Ki-Moon ; Park Hyun-Chul ; Park Chul-Hue ;
Transactions of the Korean Society of Mechanical Engineers A, volume 30, issue 6, 2006, Pages 698~704
DOI : 10.3795/KSME-A.2006.30.6.698
This paper presents an electrode shape design method for the multi-mode sensors that could deteict the selected structural multiple modes. The structure used for this study is an isotropic cantilever beam type with a PVDF (polyvinylidene fluoride) which is bonded onto the structure as a sensor. The shape optimization problem is solved by using Genetic Algorithm (GA) with an appropriate objective function. The performance of analytical optimal shape sensor is compared with that of experimental work. The results show that the, obtained electrode shape sensors have good performance to detect the multiple vibration modes simultaneously.
Subdomain-Based Finite Element Method for Thermomechanical Analysis with Thermal Radiation
Shin Eui-Sup ; Jin Ji-Man ;
Transactions of the Korean Society of Mechanical Engineers A, volume 30, issue 6, 2006, Pages 705~712
DOI : 10.3795/KSME-A.2006.30.6.705
A finite element method based on the penalized subdomain-interface framework is proposed for fully-coupled, nonlinear thermomechanical analyses with thermal contact anuor radiation boundaries. In the variational formulation, a well-known penalty functional scheme is adopted for connecting subdomains and interfaces that satisfy various continuity requirements. As a logical consequence, the whole domain can be arbitrarily divided into independently-modeled subdomains without considering the conformity of meshes along their interfaces. Since the nonlinearities due to the contact and radiation boundaries can be localized within a few subdomains, the computational efficiency of the present method is greatly increased with appropriate solution algorithms. By solving some numerical problems, these advantageous features are confirmed carefully.
Monitoring of Micro-Drill Wear by Using the Machine Vision System
Choi Young-Jo ; Chung Sung-Chong ;
Transactions of the Korean Society of Mechanical Engineers A, volume 30, issue 6, 2006, Pages 713~721
DOI : 10.3795/KSME-A.2006.30.6.713
Micro-drill wear deteriorates accuracy and productivity of the micro components. In order to improve productivity and qualify of micro components, it is required to investigate micro-drill wear exactly. In this study, a machine vision system is proposed to measure the wear of micro-drills using a precision servo stage. Calibration experiments are conducted to compensate for the machine vision system. In this paper, worn volume, area and length are defined as wear amounts. Micro-drill wear is reconstructed as the 3D topography and the quantized wear amount by using the shape from focus (SFF) method and wear parameters. Experiments have been conducted with HSS twist micro-drills and SM45C carbon steel workpieces. Validity of the proposed machine vision system is confirmed through experiments.
A Simulation Method for Bone Growth Using Design Space Optimization
Jang In-Gwun ; Kwak Byung-Man ;
Transactions of the Korean Society of Mechanical Engineers A, volume 30, issue 6, 2006, Pages 722~727
DOI : 10.3795/KSME-A.2006.30.6.722
Bone fracture healing is one of the important topics in biomechanics, demanding computation simulations due to the difficulty of obtaining experimental or clinical results. In this study, we adopt the design space optimization method which was established by the authors as a tool for the simulation of bone growth using its evolutionary characteristics. As the mechanical stimulus, strain energy density is used. We assume that bone tissues over a threshold strain energy density will be differentiated and bone tissues below another threshold will be resorbed. Under compression and torsion as loadings, the filling process of the defect is well illustrated following the given mechanical criterion. It is shown that the design space optimization is an excellent tool for simulating the evolutionary process of bone growth, which has not been possible otherwise.
Improvement of Sound Quality for the Vehicle HVAC System Using Optimum Layout of Damping Material
Oh Jae-Eung ; Hwang Dong-Kun ; Park Sang-Gil ; Yoon Tae-Kun ; Sim Hyoun-Jin ; Lee Jung-Youn ;
Transactions of the Korean Society of Mechanical Engineers A, volume 30, issue 6, 2006, Pages 728~733
DOI : 10.3795/KSME-A.2006.30.6.728
The reduction of the Vehicle interior noise has been the main interest of NVH engineers. The driver`s perception on the vehicle noise is affected largely by psychoacoustic characteristic of the noise as well as the SPL. In particular, the HVAC sound among the vehicle interior noise has been reflected sensitively in the side of psychology. In previous study, we have developed to verify identification of source for the vehicle HVAC system through multiple-dimensional spectral analysis. Also we carried out objective assessments on the vehicle HVAC noises and subjective assessments have been already performed with 30 subjects. In this study, the linear regression models were obtained for the subjective evaluation and the sound quality metrics. The regression procedure also allows you to produce diagnostic statistics to evaluate the regression estimates including appropriation and accuracy. Appropriation of regression model is necessary to
value and F-value. And testing for regression model is necessary to independence, homoscedesticity and normality. Also we selected optimum layout of damping material using Taguchi method. As a result of application, sound quality is improved more quietly, powerfully, even though costly, and smoothly.
A Study on the Development and Performance Test of the Paddle-type Fluidized Dryer
Kum Sung-Min ; Lee Kwang-Cheol ; Kong Min-Seog ; Yoo Byung-Hun ; Lee Hyun-Gu ; Lee Chang-Eon ;
Transactions of the Korean Society of Mechanical Engineers A, volume 30, issue 6, 2006, Pages 734~740
DOI : 10.3795/KSME-A.2006.30.6.734
The purpose of this study is to develop and commercialize a paddle-type fluidized dryer. The drying system used in this study, was designed to attach a paddle-type fluidized mixer to a dryer. The drying system is based on the drying method to generate thermal contacts, as fluidized layers are generated due to a paddle mechanism. Accordingly, the time of drying is short and material damage is very little. Also, the drying system operates as a closer system so it can be utilized not only for food and chemical materials, but also for environmental pollution materials. According to its performance test, the drying system is possible to dry low-moisture contents and its drying performance is outstanding. In conclusion, the drying system designed for this study, is likely to have great potential for commercialization.