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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
Design of a Dexterous Anthropomorphic Robot Hand
Chi Ho-June ; Lee Sang-Hun ; Choi Byung-June ; Choi Hyouk-Ryeol ;
Transactions of the Korean Society of Mechanical Engineers A, volume 30, issue 4, 2006, Pages 357~363
DOI : 10.3795/KSME-A.2006.30.4.357
According to the study of grasping of the human hand, it is noted that the metacarpal link of the thumb plays the key role in power grasping. Also the face of fingertip can be discriminated into five parts depending on the grasping modalities such as pinch grasp, fingertip grasp and power grasp. In this paper, the design of the anthropomorphic robot hand which has a thumb and three fingers is proposed. A difference of SKKU hand II from the previous gripperlike robot hand is that the metacarpal bone is connected between the thumb and the palm. This thumb mechanism is specially designed to get the degree of freedom which can realize flexible motions relative to objects. Based on the analysis, the hand mechanism is developed. Since the driving circuits for the hand are embedded in the hand, only the communication lines supporting CAN protocol with DC power cable are necessary as the input. A new robot is manufactured and feasibility of the hand is validated through preliminary experiments.
Development of Tactile Sensor for Detecting Contact Force and Slip
Choi Byung-June ; Kang Sung-Chul ; Choi Hyouk-Ryeol ;
Transactions of the Korean Society of Mechanical Engineers A, volume 30, issue 4, 2006, Pages 364~372
DOI : 10.3795/KSME-A.2006.30.4.364
In this paper, we present a finger tip tactile sensor which can detect contact normal force as well as slip. The sensor is made up of two different materials, such as polyvinylidene fluoride (PVDF) known as piezoelectric polymer, and pressure variable resistor ink. In order to detect slip on the surface of the object, two PVDF strips are arranged along the normal direction in the robot finger tip and the thumb tip. The surface electrode of the PVDF strip is fabricated using silk-screening technique with silver paste. Also a thin flexible force sensor is fabricated in the form of a matrix using pressure variable resistor ink in order to sense the static force. The developed tactile sensor is physically flexible and it can be deformed three-dimensionally to any shape so that it can be placed on anywhere on the curved surface. In addition, a tactile sensing system is developed, which includes miniaturized charge amplifier to amplify the small signal from the sensor, and the fast signal processing unit. The sensor system is evaluated experimentally and its effectiveness is validated.
A Multi-chip Microelectrofluidic Bench for Modular Fluidic and Electrical Interconnections
Chang Sung-Hwan ; Suk Sang-Do ; Cho Young-Ho ;
Transactions of the Korean Society of Mechanical Engineers A, volume 30, issue 4, 2006, Pages 373~378
DOI : 10.3795/KSME-A.2006.30.4.373
We present the design, fabrication, and characterization of a multi-chip microelectrofluidic bench, achieving both electrical and fluidic interconnections with a simple, low-loss and low-temperature electrofluidic interconnection method. We design 4-chip microelectrofluidic bench, having three electrical pads and two fluidic I/O ports. Each device chip, having three electrical interconnections and a pair of two fluidic I/O interconnections, can be assembled to the microelectofluidic bench with electrical and fluidic interconnections. In the fluidic and electrical characterization, we measure the average pressure drop of
Pa/mm with the nonlinearity of 3.1 % for the flow-rates of
in the fluidic line. The pressure drop per fluidic interconnection is measured as 0.19kPa. Experimentally, there are no significant differences in pressure drops between straight channels and elbow channels. The measured average electrical resistance is
in the electrical line. The electrical resistance per each electrical interconnection is measured as
. Mechanically, the maximum pressure, where the microelectrofluidic bench endures, reaches up to
The Structural Design for Nonlinear Hyperelastic Materials Based on CFD
Jung Dae-Seok ; Kim Ji-Young ; Lee Jong-Moon ; Park Young-Chul ;
Transactions of the Korean Society of Mechanical Engineers A, volume 30, issue 4, 2006, Pages 379~386
DOI : 10.3795/KSME-A.2006.30.4.379
The hyper-elastic material has been used gradually and its range was extended all over the industry. The performance prediction of hyper-elastic material was required not only experimental methods but also numerical methods. In this study, we presented the process how to use numerical method for hyper-elastic material and applied it to seat-ring of butterfly valve. The finite element analysis was executed to evaluate the mechanical characteristics of hyper-elastic material. And the optimum model considered conditions and features. According to that model, the load conditions were obtained by using CFD analysis.
Analysis of Design Parameter of Structural Modification using Change of Dynamic Characteristics
Oh Jae-Eung ; Lee Jung-Woo ; Lee Jung-Youn ;
Transactions of the Korean Society of Mechanical Engineers A, volume 30, issue 4, 2006, Pages 387~392
DOI : 10.3795/KSME-A.2006.30.4.387
This paper predicts the modified mass and stiffness of structure using the sensitivity coefficients with the iterative method. The sensitivity coefficients are obtained by the change of the eigenvectors according to structural modification. The method is applied to an examples of a 3 degree of freedom system by modifying mass and stiffness. The predicted mass and stiffness are in good agreement with these from the structural reanalysis using the modified mass and stiffness.
Assessment of In-plane Size Effect of Nuclear Materials Based on Damage Mechanics
Chang Yoon-Suk ; Lee Tae-Rin ; Choi Jae-Boong ; Seok Chang-Sung ; Kim Young-Jin ;
Transactions of the Korean Society of Mechanical Engineers A, volume 30, issue 4, 2006, Pages 393~401
DOI : 10.3795/KSME-A.2006.30.4.393
The influences of stress triaxiality on ductile fracture have been investigated for various specimens and structures. With respect to a transferability issue, recently, the interests on local approaches reflecting micromechanical specifics are increased again due to rapid progress of computational environments. In this paper, the applicability of the local approaches has been examined through a series of finite element analyses incorporating modified GTN and Rousselier models as well as fracture toughness tests. The ductile crack growth of nuclear carbon steels is assessed to verify the transferability among compact tension (CT) specimens with different in-plane size. At first, the basic material constants were calibrated for standard CT specimens and used to predict fracture resistance (J-R) curves of larger CT specimens. Then, the in-plane size effects were examined by comparing the numerically estimated J-R curves with the experimentally determined ones. The assessment results showed that the in-plane size effect should be considered for realistic engineering application and the damage models might be used as useful tool for ductile fracture evaluation.
Mechanical Properties of Dissimilar Friction Welded Steel Bars in Relation to Post Weld Heat Treatment
Kong Yu-Sik ; Kim Seon-Jin ;
Transactions of the Korean Society of Mechanical Engineers A, volume 30, issue 4, 2006, Pages 402~408
DOI : 10.3795/KSME-A.2006.30.4.402
Dissimilar friction welding were produced using 15(mm) diameter solid bar in chrome molybedenum steel(KS SCM440) to carbon steel(KS S45C) to investigate their mechanical properties. The main friction welding parameters were selected to endure good quality welds on the basis of visual examination, tensile tests, Vickers hardness surveys of the bond of area and H.A.Z and microstructure investigations. The specimens were tested as-welded and post-weld heat treated(PWHT). The tensile strength of the friction welded steel bars was increased up to 100% of the S45C base metal under the condition of all heating time. Optimal welding conditions were n
Analysis of a Plate-type Piezoelectric Composite Unimorph Actuator Considering Thermal Residual Deformation
Goo Nam-Seo ; Woo Sung-Choong ;
Transactions of the Korean Society of Mechanical Engineers A, volume 30, issue 4, 2006, Pages 409~419
DOI : 10.3795/KSME-A.2006.30.4.409
The actuating performance of plate-type unimorph piezoelectric composite actuators having various stacking sequences was evaluated by three dimensional finite element analysis on the basis of thermal analogy model. Thermal residual stress distribution at each layer in an asymmetrically laminated plate with PZT ceramic layer and thermally induced dome height were predicted using classical laminated plate theory. Thermal analogy model was applied to a bimorph cantilever beam and LIPCA-C2 actuator in order to confirm its validity. Finite element analysis considering thermal residual deformation showed that the bending behavior of piezoelectric composite actuator subjected to electric loads was significantly different according to the stacking sequence, thickness of constituent PZT ceramic and boundary conditions. In particular, the increase of thickness of PZT ceramic led to the increase of the bending stiffness of piezoelectric composite actuator but it did not always lead to the decrease of actuation distance according to the stacking sequences of piezoelectric composite actuator. Therefore, it is noted that the actuating performance of unimorph piezoelectric composite actuator is rather affected by bending stiffness than actuation distance.
A Study on the Measurement of Fracture Resistance Characteristics for Steam Generator Tubes
Chang Yoon-Suk ; Huh Nam-Su ; Ahn Min-Yong ; Hwang Seong-Sik ; Kim Joung-Soo ; Kim Young-Jin ;
Transactions of the Korean Society of Mechanical Engineers A, volume 30, issue 4, 2006, Pages 420~427
DOI : 10.3795/KSME-A.2006.30.4.420
The structural and leakage integrity of steam generator tubes should be sustained against all postulated loads even if a crack is present. During the past three decades, most of the efforts with respect to integrity evaluation of steam generator tubes have been focused on limit load solutions but, recently, the applicability of elastic-plastic fracture mechanics was examined cautiously due to its effectiveness. The purpose of this paper is to introduce a testing method to estimate fracture resistance characteristics of steam generator tubes with a through-wall crack. Due to limited thickness and diameter, inevitably, the steam generator tubes themselves were tested instead of standard specimen or alternative ones. Also, a series of three dimensional elastic-plastic finite element analyses were carried out to derive closed-form estimation equations with respect to J-integral and crack extension for direct current potential drop method. Since the effectiveness of
as well as J-R curves was proven through comparison with those of standard specimens taken from pipes, it is believed that the proposed scheme can be utilized as an efficient tool for integrity evaluation of cracked steam generator tubes.
Finite Element Analysis of Nd:YAG Pulse Laser Welding for AISI 304 Stainless Steel Plate
Nam Gi-Jeong ; Kim Kwan-Woo ; Hong Jin-Uk ; Lee Jae-Hoon ; Suh Jeong ; Cho Hae-Yong ;
Transactions of the Korean Society of Mechanical Engineers A, volume 30, issue 4, 2006, Pages 428~434
DOI : 10.3795/KSME-A.2006.30.4.428
Pulse laser welding of AISI 304 stainless steel plate was simulated to find optimal welding conditions by using commercial finite element code MARC. Due to geometric symmetry, a half model of AISI 304 stainless steel plate was considered and user subroutines were applied to boundary condition for the heat transfer. Material properties such as conductivity, specific heat, mass density and latent heat were given as a function of temperature. A moving heat source was designed on the basis of experimental data. As a result, Nd:YAG laser welding for AISI 304 stainless steel was successfully simulated and it should be useful to determine optimal welding condition.
Gait Study on the Normal and ACL Deficient Patients After Ligament Reconstruction Surgery Using Chaos Analysis Method
Ko Jae-Hun ; Moon Byung-Young ; Suh Jeung-Tak ; Son Kwon ;
Transactions of the Korean Society of Mechanical Engineers A, volume 30, issue 4, 2006, Pages 435~441
DOI : 10.3795/KSME-A.2006.30.4.435
The anterior cruciate ligament(ACL) is an important stabilizer of knee joint. The ACL injury of knee is common and a serious ACL injury leads to ligament reconstruction surgery. Gait analysis is essential to identify knee condition of patients who display abnormal gait. The purpose of this study is to evaluate and classify knee condition of ACL deficient patients using a nonlinear dynamic method. The nonlinear method focuses on understanding how variations in the gait pattern change over time. The experiments were carried out for 17 subjects(l2 healthy subjects and five subjects with unilateral deficiency) walking on a motorized treadmill for 100 seconds. Three dimensional kinematics of the lower extremity were collected by using four cameras and KWON 3D motion analysis system. The largest Lyapunov exponent calculated from knee joint flexion-extension time series was used to quantify knee stability. The results revealed the difference between healthy subjects and patients. The deficient knee was significantly unstable compared with the contralateral knee. This study suggests an evaluation scheme of the severity of injury and the level of recovery. The proposed Lyapunov exponent can be used in rehabilitation and diagnosis of recoverable patients.
Modal Analysis of Rotor System with Anisotropic Stator and Asymmetric Rotor in the Presence of Breathing Crack
Han Dong-Ju ;
Transactions of the Korean Society of Mechanical Engineers A, volume 30, issue 4, 2006, Pages 442~450
DOI : 10.3795/KSME-A.2006.30.4.442
This paper describes the new modal analysis method to detect the presence of the breathing crack in a general rotor system with disk asymmetry and stator anisotropy. It is proposed that the modal analysis using directional frequency response functions (dFRFs), which, accounting for the directivity in modes, clears the heavily over-lapping of other harmonics occurring from non-isotropic properties in addition to those due to crack, can provide an effective method to detect the modes by a crack. The simulations from the simple general rotor model show that the r-dFRFs (reverse dFRFs) for asymmetry confirms a good indicator of the presence of the breathing crack and the instability is primarily influenced by the shaft asymmetry than the breathing crack.
A Study on the Light Cylinder Using Chemical Milling
Yoo Joon-Tae ; Yoon Jong-Hoon ; Jang Young-Soon ; Yi Yeong-Moo ; Kang Suk-Bong ; Lee Jong-Woong ;
Transactions of the Korean Society of Mechanical Engineers A, volume 30, issue 4, 2006, Pages 451~456
DOI : 10.3795/KSME-A.2006.30.4.451
The process for reducing the weight of the structure is chiefly performed by the machine processing. But, increasing the weight for strength of welding zone and geometrical defect are occurred in machine processing. In this study, chemical milling is applied to reduce the weight of the cylinder. Before chemical milling is applied to the cylinder, specimen testing is performed. After the specimen testing, NaOH 15% is selected to perform the chemical milling. After the chemical milling, the velocity of reagent is 0.0016 mm/min and the thickness of cylinder is about 2.4 mm after chemical milling.
Analysis of Isometry of the Anterior Cruciate Ligament for Optimal Ligament Reconstruction
Park Jung-Hong ; Suh Jeung-Tak ; Moon Byung-Young ; Son Kwon ;
Transactions of the Korean Society of Mechanical Engineers A, volume 30, issue 4, 2006, Pages 457~464
DOI : 10.3795/KSME-A.2006.30.4.457
The anterior cruciate ligament (ACL) is liable to a major injury that often results in a functional impairment requiring surgical reconstruction. The success of reconstruction depends on such factors as attachment positions, initial tension of ligament and surgical methods of fixation. The purpose of this study is to find isometric positions of the substitute during flexion/extension. The distance between selected attachments on the femur and tibia was computed from a set of measurements using a 6 degree-of-freedom magnetic sensor system. A three-dimensional knee model was constructed from CT images and was used to simulate length change during knee flexion/extension. This model was scaled for each subject. Twenty seven points on the tibia model and forty two points on the femur model were selected to calculate length change. This study determined the maximum and minimum distances to the tibial attachment during flexion/extension. The results showed that minimum length changes were
). The most isometric region was both the posterosuperior and anterior-diagonal areas from the over-the-top. The proposed method can be utilized and applied to an optimal reconstruction of ACL deficient knees.
The Optimal Design for Noise Reduction of the Intake System in Automobile Using Kriging Model
Sim Hyoun-Jin ; Ryu Je-Seon ; Cha Kyung-Joon ; Oh Jae-Eung ;
Transactions of the Korean Society of Mechanical Engineers A, volume 30, issue 4, 2006, Pages 465~472
DOI : 10.3795/KSME-A.2006.30.4.465
Recently, the regulations of the government and the concerns of people have rise to the interest in noise pollution levels as compared to other vehicles. In this area, many researchers have studied to reduce this noise in the field of automotive engineering. This paper proposes an optimal design scheme to reduce the noise of the intake system by adapting Kriging with two meta-heuristic techniques. For this, as a measuring tool for the performance of the intake system, the performance prediction software, was used. Then, the length and radius of each component of the current intake system are selected as input variables and the orthogonal arrays is adapted as a space-filling design. With these simulated data, we can estimate a correlation parameter in Kriging by solving the nonlinear problem with a genetic algorithm and find an optimal level for the intake system by optimizing Kriging estimated with simulated annealing. We notice that this optimal design scheme gives noticeable results and is a preferable way to analyze the intake system. Therefore, an optimal design for the intake system is proposed by reducing the noise of its system.
Analytical and Experimental Studies on the Natural Frequency of a Composite Train Carbody
Jeong Jong-Cheol ; Cho Sea-Hyun ; Seo Seong-Il ; Kim Jung-Seok ;
Transactions of the Korean Society of Mechanical Engineers A, volume 30, issue 4, 2006, Pages 473~480
DOI : 10.3795/KSME-A.2006.30.4.473
This paper explains analytical and experimental studies to evaluate the natural frequency of a composite carbody of Korean tilting train. The composite carbody with length of 23m was manufactured as a sandwich structure composed of 40mm-thick aluminium honeycomb core and 5mm-thick woven fabric carbon/epoxy face. From the finite element analysis, the 1st bending and 1st twisting natural frequency of the composite carbody were 11.67Hz and 14.4Hz, respectively. In order to verify the analytical results, the natural frequency measuring tests were performed. The measured 1st bending and twisting natural frequencies of the composite carbody were 10.25Hz and 11.0Hz, respectively. Both of these results satisfied the design requirement.