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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 20, Issue 12 - Dec 1996
Volume 20, Issue 11 - Nov 1996
Volume 20, Issue 10 - Oct 1996
Volume 20, Issue 9 - Sep 1996
Volume 20, Issue 8 - Aug 1996
Volume 20, Issue 7 - Jul 1996
Volume 20, Issue 6 - Jun 1996
Volume 20, Issue 5 - May 1996
Volume 20, Issue 4 - Apr 1996
Volume 20, Issue 3 - Mar 1996
Volume 20, Issue 2 - Feb 1996
Volume 20, Issue 1 - Jan 1996
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Mechanical Property and Fatigue Bahavior of
Metal Matrix Composite
Song, Jeong-Il ; LIm, Hong-Jun ; Han, Gyeong-Seop ;
Transactions of the Korean Society of Mechanical Engineers A, volume 20, issue 3, 1996, Pages 753~764
DOI : 10.22634/KSME-A.19126.96.36.1993
The metal matrix composites(MMC) are currently receiving a great deal of attention. These composites possess exellent mechanical and physical properties such as modulus, strength, wear resistance and thermal stability, which make them very attractive for use in automotive piston. In this study,
(15%) composites are fabricated by the squeeze casting method. Mechanical properties such as tensile strength and ductility are performed at room and elevated temperature(
), respectively. Through thermomechanical analyser, thermal expansion coefficient of
composites are conducted for ranging from room temperature to (
.And bending fatigue tests are also performed by the rotary bending machine at room temperature.The tensile strength and elastic modulus have been improved up to 38% and 35% by the addition of the reinforcements, respectively. Thermal expansion coefficients of MMCs which is located normal and parralel to the applied pressure are showed slightly different less than 10%. Fatigue strengh of the composite was improved by about 20% compared with that of unreinforced Al alloy. The results of this study will be used to understand the basic fracture behavior of MMCs and eventually to expand the applocation of MMCs as a machine parts undertaken various loadings.
A Study on Neural Network Modeling of Injection Molding Process Using Taguchi Method
Choe, Gi-Heung ; Yu, Byeong-Gil ; Hong, Tae-Min ; Lee, Gyeong-Don ; Jang, Nak-Yeong ;
Transactions of the Korean Society of Mechanical Engineers A, volume 20, issue 3, 1996, Pages 765~774
DOI : 10.22634/KSME-A.19188.8.131.525
Computer Integrated Manufacturing(CIM) requires models of manufacturing processes to be implemented on the computer. These models are typically used for determining optimal process control parameters or designing adaptive control systems. In spite of the progress made in the mechanistic modeling, however, empirical models derived from experimental data play a maior role in manufacturing process modeling. This paper describes the development of a meural metwork medel for injection molding. This paper describes the development of a nueral network model for injection molding process. The model uses the CAE analysis data based on Taguchi method. The developed model is, then, compared with the traditional polynomial regression model to assess the applicabilit in practice.
Optimal Design of Cylindrically Laminated Composite Shells for Strength
Kim, Chang-Wan ; Hwang, Un-Bong ; Park, Hyeon-Cheol ; Shin, Dae-Sik ; Park, Ui-Dong ;
Transactions of the Korean Society of Mechanical Engineers A, volume 20, issue 3, 1996, Pages 775~787
DOI : 10.22634/KSME-A.19184.108.40.2065
An optimization procedure is proposed for the design of cylindrically laminated composite shell having midplane symmetry and subjected to axial force, torsion and internal pressure. Tsai-Wu and Tsai-Hill failure criteria are taken as objective functions. The stacking sequence represents the design variable. The optimal design formulation based on state space method is adopted and solution proccedure is described with the emphasis on the method of calculations of the design sensitivities. A gradient projection algorithm is employed for the optimization process. Numerical results are presented for the several test problems.
Optimum Cam Profile Design of VTR Deck Using the Response Stuface Analysis
Han, Hyeong-Seok ; An, Hyeong-Jin ; Park, Tae-Won ;
Transactions of the Korean Society of Mechanical Engineers A, volume 20, issue 3, 1996, Pages 788~795
DOI : 10.22634/KSME-A.19220.127.116.118
In this paper, and optimum profile of a cam being used in a VTR Deck mechanism is designed by the response surface analysis. The objective function of the design is to reduce driving torque of the pinch roller system that is used to compress video tape to the capstan motor axia. The pinch roller system that will be designed is modeled using the general purpopse mechanism analysis program DADS. The computer model is compared with the physical system for reliability. A model function to represent relationship between design variables and the objective function is estimated by the response surface analysis. Once the model function is reliably estimated the optimal design is carried out using the model function and each design variable's boundaries. To verify improvement of the pinch roller system, a prototype for the pinch rooler system is made and tested. From the test result, an optimum cam profile to resuce driving torque of the pinch roller system is verified.
An Experimental Study on the Fabrication and the Compression Behavior of Semi-Solid Aluminum Material
Gang, Chung-Gil ; Yun, Jong-Hun ;
Transactions of the Korean Society of Mechanical Engineers A, volume 20, issue 3, 1996, Pages 796~805
DOI : 10.22634/KSME-A.1918.104.22.1686
A fabrication process using Semi-Solid Material(SSM) for casting alloy has been studied to demonstrate the possibility for mass production with controlled solid fraction. The SSM was fabricated under the various solid fractions and preheating temperatures of mold. The behaviour of a semi-solid global microstructure has been investigated under the various heating and die temperatures for solid fraction. The effect of reheating time on the globularization of SSM microstructure has been investigated in detail. And the behavior of SSM which has the solid fraction 0.5 was observed under compression. The stress strain relationship was also obtained for the compression test of semi-solid materials. The rheological behaviour of semi-solid with globule microstructure was investigated as a function of the compression velocity under isothermal holing conditions.
Study on the Effects of Surface Treatment and Stitching on the Fracture Behavior of Composite Laminates
Hong, S.Y ; Hwang, W ; Park, H.C ; Han, K.S ;
Transactions of the Korean Society of Mechanical Engineers A, volume 20, issue 3, 1996, Pages 806~815
DOI : 10.22634/KSME-A.1922.214.171.1246
The interlaminar fracture behavior of woven laminates under static and cyclic loadings has been studied using DCB(double cantilever beam) specimens. The effects of surface treatment and stiching on the fracture behavior of composite laminates are investigated experimentally. Fracture toughness has been improved by surface treatment because the surface treatment can change the fracture mechanism of laminates. SCB(stitched cantilever beam) model has been proposed to quantify the effect of through-thickness resinforcement(stiching) in improving the delamination crack growth resistance. Distributed loads which are transfered to through-thickness fibers can be calculated by the SCB model. And fracture energy increase due to the distributed load can be predicted by a power function of the distributed load. A new parameter agreed well proposed predict fatigue crack growth rate. The predictions using this parameter agreed well with the experimental data.
Creep Densification of Metal Powder Compacts
Song, Min-Cheol ; Kim, Hong-Gi ; Kim, Gi-Tae ;
Transactions of the Korean Society of Mechanical Engineers A, volume 20, issue 3, 1996, Pages 816~824
DOI : 10.22634/KSME-A.19126.96.36.1996
The densification behaviors of copper powder under high temperature processing were investigated. Experimental data were obtained for copper powder under hot isostatic pressing, hot pressing and uniaxial compression. Finite element calculations from the constitutive models by McMeeking and co-workers were compared with the experimental data, The agreements between experimental data and theoretical calculations are reasonably good when hydrostatic stress is dominant, but not as good then deviatoric stress increases.
On the Explosive Welding Characteristics of Steel-Titanium Dissimilar Materials Using finite Element Method
Kim, Chung-Kyun ; Kim, Myung-Koo ; Sim, Sang-Han ; Moon, Jeong-Gi ;
Transactions of the Korean Society of Mechanical Engineers A, volume 20, issue 3, 1996, Pages 825~831
DOI : 10.22634/KSME-A.19188.8.131.525
Using the two-dimensional hydrocode HI-DYNA2D, a calculation on the explosive selding of dissimilar plates(Steel Titanium) was made for the pressure, temperature, velocity and impact ingles adjacent to the collision point during the welding process. The FEM result indicates that optimal stand-off distance of initially parallel set-up is 3-5mm for various values of the explosive thickness. The calculation shows that when the explosive thickness is around 30mm, the temperature of welding point which is strongly related to the metallic jet formation is 2, 000-3, 500K for the given stand-off distance.
Fatigue Life Prediction of Circular Notched CFRP Laminates
Heo, Jae-Seok ; Hwang, Un-Bong ; Park, Hyeon-Cheol ; Han, Gyeong-Seop ;
Transactions of the Korean Society of Mechanical Engineers A, volume 20, issue 3, 1996, Pages 832~842
DOI : 10.22634/KSME-A.19184.108.40.2062
Fatigue life prediction and fatigue behavior of circular notched carbon fiber reinforced plastic laminates are presented. Point and average stress criteria by Whitney and Nuismer are generalized to fatigue fracture criteria for notched laminates. Residual strength degradation model and the assumptions on the stress redistribution are introduced during the derivation of prediction equations. S-N curve, Basquin's relation, and H and H's FLPE1 are chosen for evaluation of residual strength of unnotched laminates and six prediction equations are derived. Experiments are performed using Graphite/Epoxy laminates whose fiber orientation is $[0
]s. Presented prediction equations are reasonably close to experimental data and proposed appoach is found to be suitable to predict fatigue life of notched composite laminates.
Robust Modal Parameter Idnentification Using Total Least Square Method
Jeong, Weui-Bong ; Kim, Jun-Yeop ; Kim, Hyun ;
Transactions of the Korean Society of Mechanical Engineers A, volume 20, issue 3, 1996, Pages 843~849
DOI : 10.22634/KSME-A.19220.127.116.113
The least square estimation is used frequently in experimental modal analysis techinque to eliminate noise signals. However, identified modal parameters are sometimes inaccurate, since the least squre estimation is sensitive to noise. In this paper, a new total least squre estimation, which is robust to noise signals, is developed and applied to experimental modal analysis technique such as Prony method and Circle Fit method. Several simulated results show that the proposed method is robuster to noise than conventional method.
A Study on the Design of a Maneuvering Controller for Submersible Vehicles
Yang, Seung-Yun ; Lee, Man-Hyung ;
Transactions of the Korean Society of Mechanical Engineers A, volume 20, issue 3, 1996, Pages 850~860
DOI : 10.22634/KSME-A.1918.104.22.1680
This paper considers a sliding mode controller for a depth and course control of a class of submersible Vehicles. Since the vehicle used here shows complex dynamic characteristics sensitive to speed variation and buoyancy, robustness in control of vertical and horizontal plane motions of the vehicle is achieved by using the sliding mode controller of which a structure varies according to a pre-designed principle, so called the variable structure control. To compare this controller with another in robustness, PID controller for the same model of vehicle is designed. From various simulations for two controllers, it is shown that the sliding mode controller is the more robust anainst to modeling errors and disturbances.
Simulation of Fuzzy Shape Control for Cold-Rolled Strip with Randomly Irregular Strip Shape
Jung, Jong-Yeob ; Im, Yong-Taek ;
Transactions of the Korean Society of Mechanical Engineers A, volume 20, issue 3, 1996, Pages 861~871
DOI : 10.22634/KSME-A.1922.214.171.1241
In this study, a fuzzy control algorithm was developed for the randomly irregular shape of cold-rolled strip. Currently developed fuzzy control algorithm consists of two parts: the first part calculates the changes of work and intermediate roll bender forces based on the symmetric part of the irregular strip shape, and the second part calculates the weighting factors based on the asymmetric part and modifies the pre-determined roll bender forces according to the weighting factors. As a result of this, bender froces applied at the both sides of the cold-rolled strip were different. In order to simulate the continuous shape control. fuzzy controller developed was linked with emulator which was developed based on neural network. The fuzzy controller and emulator developed simulated the cold rolling process until irregular shape converged to a tolerable range in producing uniform cross-sectional strip shape. The results obtained from the simulation were reasonable for various irregular strip shapes.
Structural Homology Design Using Equality Constraints
Lee, Gwon-Hui ; Park, Gyeong-Jin ;
Transactions of the Korean Society of Mechanical Engineers A, volume 20, issue 3, 1996, Pages 872~881
DOI : 10.22634/KSME-A.19126.96.36.1992
The concept of homology design has been devised for the application to large telescope structure by S.v.Hoerner. It is defined that the deformation of a structure shall be called homologous, if a given geometrical relation holds, for a given number of structural points, before, during, and after the deformation. Recently, the need of homology design in the structural design has been increase due to the required precision in the structure. Some researchers have utilized the theory on the structural design with finite element method in the late 1980s In the present investigation, a simple method using geometrical equality constraints is suggested to gain homologous deformation. The previous method is improved in that the decomposition of FEM eqation, which is very expensive, is not necessary. The basic formulations of the homology design with the optimization concept are described and several practical examples are solved to verify the usefulness and validity. Especially, a back-up structure of a satellite antenna is designed by the suggested method. The results are compared with those of existing researches.
Measurement of Mechanical Properties of a Thermally Evaporated Gold Film Using Blister Test
Moon, Ho-Jeong ; Ham, Soon-Sik ; Earmme, Yun-Young ; Cho, Young-Ho ;
Transactions of the Korean Society of Mechanical Engineers A, volume 20, issue 3, 1996, Pages 882~890
DOI : 10.22634/KSME-A.19188.8.131.522
Mechanical properties, including Young's modulus, residual stress and rupture strength, of a thermally evaporated gold film have been measured form a blister test. In a theoretical study, the priniple of minimum potential energy and that of virtual work have been applied to the pressurized circular membrane problem, and load-deflection relations have been derived for typical membrane deflection mode of spheroidal shape. In an experimental study, circular gold membranes of 4800 A-thickness and 3.5mm diameter were fabricated by the silicon electropolishing technique. Mecahnical properties of the thin gold films were deduced from the load-deflection curves obtained by the blister test, Young's moduli, obtianed from blister test, have been in the range of 45-70 GPa, while those of bulk gold have been in the range of 78-80 GPa. Residual stresses in the evaporated gold films have been measured as 28-110MPa in tension, The rupture strength of the gold film has turned out to be almost equal to that of dental gold alloy (310-380MPa). It has been demonstrated that the present specimen fabrication method and blister test apparatus have been effective for simultaneous measurement of Young's modulus, residual stress and repture strength of thin solid films. Especially, the electropolishing technique employed here has provided a simple and practical way to fabricate thin membranes in a circular or an arbitrary shape, which could not be obtained by the conventional anisotropic silicon mecromachining technique.
A Study on the Vision Sensor Using Scanning Beam for Welding Process Automation
You, Won-Sang ; Na, Suck-Joo ;
Transactions of the Korean Society of Mechanical Engineers A, volume 20, issue 3, 1996, Pages 891~900
DOI : 10.22634/KSME-A.19184.108.40.2061
The vision sensor which is based on the optical triangulation theory with the laser as an auxiliary light source can detect not only the seam position but the shape of seam. In this study, a vision sensor using the scanning laser beam was investigated. To design the vision sensor which considers the reflectivity of the sensing object and satisfies the desired resolution and measuring range, the equation of the focused laser beam which has a Gaussian irradiance profile was firstly formulated, Secondly, the image formaing sequence, and thirdly the relation between the displacement in the measuring surface and the displacement in the camera plane was formulated. Therefore, the focused beam diameter in the measuring range could be determined and the influence of the relative location between the laser and camera plane could be estimated. The measuring range and the resolution of the vision sensor which was based on the Scheimpflug's condition could also be calculated. From the results mentioned above a vision sensor was developed, and an adequate calibration technique was proposed. The image processing algorithm which and recognize the center of joint and its shape informaitons was investigated. Using the developed vision sensor and image processing algorithm, the shape informations was investigated. Using the developed vision sensor and image processing algorithm, the shape informations of the vee-, butt- and lap joint were extracted.
Stress Intensity Factors for an Interlaminar Crack in Composites under Arbitrary Crack Surface Loadings
Lee, Gang-Yong ; Park, Mun-Bok ; Kim, Seong-Ho ;
Transactions of the Korean Society of Mechanical Engineers A, volume 20, issue 3, 1996, Pages 901~909
DOI : 10.22634/KSME-A.19220.127.116.111
A model is constructed to evaluate the stress intensity factors(SIFs) for composites with an interlaminar crack subjected to as arbitrary crack surface loading. A mixed boundary value problem is formulated by Fourier integral transform method and a Fredholm integral equation of the second kind is derived. The integral equation is solved numerically and the mode I and II SIFs are evaluated for various shear modulus ratios between each layer, crack length to layer thickness, each term of crack surface polynomial loading and the number of layers. The mode I and II SIFs for the E- glass/epoxy composites as well as the hybrid composites are also evaluated.
Effective Conductivity of Disordered Three-Phase Media
Kim, In-Chan ;
Transactions of the Korean Society of Mechanical Engineers A, volume 20, issue 3, 1996, Pages 910~932
DOI : 10.22634/KSME-A.1918.104.22.1680
A problem of determining the effective conductivity of a useful model of sphere-matrix type, disordered three-phase composite media is considered. Specifically, a three-phase media in which two-phase composite spheres, consisting of spheres of conductivity
((phase 2) and concentric shells of conductivity
(phase 3), are randomly distributed in a matrix of conductivity
( (phase 1) is considered. As for the structure models configuring three-phase composite media, three different structure models of PCS, PS-1 and PS-2 models are defined, which are analogous to well-established PCS, PS structure models of two-phase composite media. Futhermore, a generalized PS-PCS structure model is proposed to incorporate thesee three different models in one. Effective condectivity
of multiphaes composite media is greatly influenced by the phase connectivity of each disspersed phase material, as well as phase conductivities and phase volume fractions. Phase connectivity of three-phase PCS, PS-1, PS-2 composite media is quantified by the impentrability parameter
. Mathematically rigorous first-order cluster bounds on
are derived for these models of three-phase composite media, and as computation examples, first-order cluster bounds on
for three-phase composites consisting of largely different phase conductivities are computed and compared as function of concnectivity parpmeter
. Results and discussions are given.
Numerical Analysis of Incompressible Viscous Flow with Free Surface Using Pattern Filling and Refined Flow Field Regeneration Techniques
Jeong, Jun-Ho ; Yang, Dong-Ryeol ;
Transactions of the Korean Society of Mechanical Engineers A, volume 20, issue 3, 1996, Pages 933~944
DOI : 10.22634/KSME-A.1922.214.171.1243
In this paper, two new techniques, the pattern filling and the refined flow field regeneration, based on the finite element method and Eulerian mesh advancement approach have been developed to analyze incompressible viscous flow with free surfaces. The gorerning equation for flow analysis is Navier-Stokes equation including inertia and gravity effects. The penalty and Newton-Raphson methods are used effectively for finite element formulation. The flow front surface and the volume inflow rate are calculated using the pattern filling technique to select an adequate pattern among five filling patterns at each quadrilateral control volume. By the refined flow field regeneration technique, the new flow field which renders better prediction in flow surface shape is generated and the velocity field at the flow front part is calculated more exactly. Using the new thchniques to be developed, the dam-breaking problem has been analyzed to predict flow phenomenon of fluid and the predicted front positions versus time have been compared with the reported experimental result.
Development of Numerical CCM in Pursuit of Accuracy Assessment for Coordinate Measuring Machines
Park, Hui-Jae ;
Transactions of the Korean Society of Mechanical Engineers A, volume 20, issue 3, 1996, Pages 945~959
DOI : 10.22634/KSME-A.19126.96.36.1995
In this paper, a comprehensive computer model is described which can be used to generate the volumetric error map combining the machine parametric errors and the measurement prove error, for most types of CMMs and axis configurations currently in use.
Identification of Diametrical Node Number of Travelling Wave Modes is Rotating Disk-Use of Directional Frequency Response Function
Kim, Myeong-Eop ; Lee, Chong-Won ;
Transactions of the Korean Society of Mechanical Engineers A, volume 20, issue 3, 1996, Pages 960~967
DOI : 10.22634/KSME-A.19188.8.131.520
Directional frequency response functions(dFRFs) are introduced for isotropic rotating disks, treating pairs of excitations and measurements as the complex input and output, respectively. It is shown that the dFRFs can be effectively used for separation of the forward and backward travelling wave modes and identification of the diametrical node numbers associated with modes of interst. Numerical simuations and experimental works are performed to demonstrate the analytical development and its validity.
Vibration Analysis of the Rotating Hybrid Cylindrical Shells Laminated with Metal and Composite
Lee, Young-Sin ; Kim, Young-Wann ;
Transactions of the Korean Society of Mechanical Engineers A, volume 20, issue 3, 1996, Pages 968~977
DOI : 10.22634/KSME-A.19184.108.40.2068
The linear/nonlinear vibration response of the rotating hybrid cylindrical shell with simply supported boundary condition is studied. The Ritz-Galerkin method is applied to obtain the nonlinear frequency equation, which excludes in-plane and rotatory inertia but includes bending stretching coupling terms. The bifurcation phenomena for the linear frequency and the frequency ratio(nonlinear/linear frequency ratio) are presented. The hybrid cylindrical shells are composed of composite(GFRP, CFRP) metal(aluminium, steel) with symmetric and antisymmetric stacking sequence. The effects of the Coriolis and centrifugal force are considered The results also present the effects of length-to- radies ratio, radius-to-thickness ratio, the circumferential wave number, the stacking sequence, the material property, the initial excitation amplitude and the rotating speed. The present linear frequency results are compared with those of the available literature.