• Computational Structural Engineering
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• v.10 no.4
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• pp.217-228
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• 1997

The high precision analysis by the p-version of the finite element method are fairly well established as highly efficient method for linear elastic problems, especially in the presence of stress singularity. It has been noted that the merits of the p-version are accuracy, modeling simplicity, robustness, and savings in user's and CPU time. However, little has been done to exploit their benefits in elasto-plastic analysis. In this paper, the p-version finite element model is proposed for the materially nonlinear analysis that is based on the incremental theory of plasticity using the constitutive equation for work-hardening materials, and the associated flow rule. To obtain the solution of nonlinear equation, the Newton-Raphson method and initial stiffness method, etc are used. Several numerical examples are tested with the help of the square plates with cutout, the thick-walled cylinder under internal pressure, and the circular plate with uniformly distributed load. Those results are compared with the theoretical solutions and the numerical solutions of ADINA

• Journal of the Computational Structural Engineering Institute of Korea
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• v.35 no.3
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• pp.183-190
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• 2022

The construction of an underground silo structure was the first stage of erecting the Gyeongju low-and-intermediate-level radioactive waste disposal facility. The facility, completed in 2014, has a scale of 100 000 drums and is currently in operation. The underground silo structure, 25 and 50 m in diameter and height, respectively, consists of cylindrical (for storing waste packages) and dome parts. The dome is divided into lower (connected to the operation tunnel) and upper parts. The wall of the underground silo structure is an approximately 1-m-thick reinforced concrete liner. In this study, finite element analysis was performed for each phase of the construction sequence and operation of the underground silo structure. Two-dimensional axial symmetric finite element analysis was implemented using the SMAP-3D program. Three-dimensional finite element analysis was also performed to examine the reliability of the two-dimensional axial symmetric finite element model. The structural behavior of the underground silo structure was predicted, and its structural safety was examined.

• Transactions of the Korean Society of Mechanical Engineers
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• v.15 no.1
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• pp.1-10
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• 1991

Two-dimensional explicit finite element code was developed. The transient dynamics code can analyse large deformations of non-linear materials subjected to extremely high strain rates. The Lagrangian finite element program uses an explicit time integration operator to integrate the equations of motion, thus the stiffness matrix is not introduced. Cylinder upsetting and ring compression problems are simulated to check the effects of friction and inertia force. It is shown that (1) calculated results agree very well with experimental results, (2) constant shear friction method overestimates the decrease of inner ring radius and then underestimates after on in comparison with the Coulomb friction method, and (3) the effect of the increase in initial strain rate is similar to the effect of higher frictional coefficient.

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.3
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• pp.806-819
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• 1995

A study of radiative heat heat transfer has been done in the non-orthogonal coordinate system utilizing the finite volume method and the P.1 approximation. Radiation of absorbing, emitting and scattering media in a concentric annulus has been solved using the non-orthogonal coordinate and the calculations were compared with the existing results. The results obtained from the analysis using the finite volume method are in good agreement with the existing calculations for all optical thicknesses. It was also shown that for only optically thick cases, P-1 approximation can be used in a non-orthogonal coordinate. Convective heat transfer analysis has been carried out to obtain the temperature fields in a cross flow around a circular cylinder and the finite volume method was applied in the non-orthogonal coordinate system to analyze radiative heat transfer. Effects of the optical thickness, the ratio of the surface temperature of the cylinder tot he free stream temperature, and the scattering albedo on radiation have been presented.

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.4
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• pp.39-48
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• 2005

Finite element analyses have been performed for the purpose of obtaining the robust and reliable design of engine cylinder block. Fatigue under high cycle operating loads is a primary concern and is evaluated by a probabilistic method. The robust and reliable design by a probabilistic method can provide satisfactory design conditions for the performance of the system under the influence of noise factors. Therefore, the design by this method will be desensitized to the uncontrollable noise factors. The simple methodology evaluates the distortion of main bore is proposed for the purpose of maintaining a well-controlled clearance between the crankshaft and main bores. The proposed methodology has proven a capability of predicting the distortion of the main bore under assembly, thermal, and firing loads. The calculated results are correlated well with the experimental ones.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.6
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• pp.2267-2275
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• 2013

Existing conventional model for analysis of shallow water flow just assumed the internal boundary condition as free-slip, which resulted in the wrong prediction about the velocity, vorticity, water level, shear stress distribution, and time variation of drag and lift force around a structure. In this study, a finite element model that can predict flow characteristics around the structure accurately was developed and internal boundary conditions were generalized as partial slip condition using slip length concept. Laminar flow characteristics behind circular cylinder were analyzed by varying the internal boundary conditions. The simulation results of (1) time variations of longitudinal and transverse velocities, and vorticity; (2) wake length; (3) vortex shedding phenomena by slip length; (4) and mass conservation showed that the vortex shedding had never observed and laminar flow like creeping motion was occurred under free-slip condition. Assignment of partial slip condition changed the velocity distribution on the cylinder surface and influenced the magnitude of the shear stress and the occurrence of vorticity so that the period of vortex shedding was reduced compared with the case of no slip condition. The maximum mass conservation error occurred in the case of no slip condition, which had the value of 0.73%, and there was 0.21 % reduction in the maximum mass conservation error by changing the internal boundary condition from no slip to partial slip condition.

• Computational Structural Engineering
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• v.10 no.2
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• pp.213-223
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• 1997

Calculation of elastic wave fields has important applications in a variety of engineering fields including NDE (Non-destructive evaluation). Scattering problems have been investigated by numerous authors with different solution schemes. For simple geometries of the scatterers (e.g., cylinders or spheres), the analysis of steady-state elastic wave scattering has been carried out using analytical techniques. For arbitrary geometries and multiple inclusions, numerical methods have been developed. Special finite element methods, e.g., the infinite element method and a hybrid method called the Global-Local finite element method have also been developed for this purpose. Recently, the boundary integral equation method has been used successfully to solve scattering problems. In this paper, a volume integral equation method (VIEM) is proposed as a new numerical solution scheme for the solution of general elasto-dynamic problems in unbounded solids containing multiple inclusions and voids or cracks. A boundary integral equation method (BIEM) is also presented for elastic wave scattering problems. The relative advantage of the volume and boundary integral equation methods for solving scattering problems is discussed.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.974-979
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• 2004

The fluidic muscle cylinder consist of an air bellows tube, flanges and lock nuts. It's features are softness of material and motion, simplicity of structure, low production cost and high power efficiency. In this study, we carried out the finite element modelling and analysis about the main design variables such as contraction ration and force, diameter increment of fluidic muscle cylinder. On the basis of finite element analysis, the prototype of fluidic muscle cylinder was manufactured and tested. Finally, we compared the results between the test and the finite element analysis.

• Transactions of the Korean Society of Automotive Engineers
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• v.4 no.5
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• pp.187-196
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• 1996

In this study, 3-dimensional finite element model of a diesel engine cylinder head was made to accomplish heat transfer analysis and also thermal stress and deformation analysis. Heat release analysis and Nusselt-Reynolds correlations were applied to determine the convective boundary conditions which are required for heat transfer analysis to calculate temperature distribution. Thermal stress distribution was also investigated from heat transfer analysis results. Steady state temperature and heat flux were measured by using K-type thermocouples and then compared with numerical results to give a guarantee for the propriety of numerical analyses.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.1293-1296
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• 2007

In this paper, present a finite element method to reduce vibration of a cylindrical structure by avoiding resonance between motor and structure. To analysis the modes of structure, some different FE models (different places and combinations of ribs) of the structure with free-free condition were built and compared.