• Communications for Statistical Applications and Methods
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• v.19 no.4
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• pp.527-536
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• 2012

In this paper we analyze the effect of circular variables such as wind direction, time and month on the ozone level. In particular, we examined the effect of wind direction by exploratory data analysis methods and provide the correlation and regression analyzes in the cases including all circular explanatory variables. In the analysis, we convert time and month variables to circular variables and analyze the effect of these variables on regression analysis; in addition, we also consider circular-circular regression. We used weather condition and air pollution data collected from Dongdaemoon district of Seoul in 2007.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2003.10a
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• pp.227-234
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• 2003

This study presents the stress evaluation equations of circular column-box beam connection in steel frame piers. FEM analysis were carried out for circular column-box beam connection. Analysis models were made for design parameters such as joint angle, span length-width ratio(L/B), sectional-area ratio(S=A/sub w/A/sub f/), and circular column-box beam stiffness ratio(Ic/Ib). Analysis results were compared to the existing equation. Based on analysis results the stress evaluation equations of circular column-box beam connection are proposed by regression analysis.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.18 no.6
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• pp.681-689
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• 2008

This paper is concerned with the free vibration analysis of a circular plate with an eccentric circular hole by the Independent coordinate coupling method(ICCM). It was proved in the previous study that the ICCM can accurately predict the natural frequencies and mode shapes of the annular plates and can also be used for the free vibration analysis of the simply-supported circular plate with an eccentric circular hole. In this study, the clamped and free boundary conditions were considered for the circular plate. The numerical results show that the ICCM can be used effectively for the free vibration problem of circular plate with an eccentric hole compared to the finite element method.

• Journal of KSNVE
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• v.4 no.3
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• pp.283-295
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• 1994

This work presents the experimental and finite element analysis results for the free vibration of 4 edges clamped, isotropic square plates with 2 collinear circular holes. Natural frequencies of finite element analysis are obtained for the complete square plate, the square plates with a central circular hole and the square plates with 2 collinear circulare holes. And natural frequencies are experimentally measured for the complete square plate, the square plate with a central circular hole(d = 150 mm) and the square plates with 2 collinear circular holes. Agreement between experimental and FEM results is excellent. Mode shapes in special case are presented. The conclusions of the study are as follows. There is little variation of nondimensional frequency parameters for the first six mode when the aspect ratio of circular hole is less than 1/6 in the isotropic square plates with 2 collinear circular holes. And the first nondimensional frequency parameter doesn't vary as the aspect ratio of circular hole increase.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.9
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• pp.9-17
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• 1999

This investigation is the result of the structural analysis by finite element method for optimal design of the cross beam with circular holes of the electric car-body. in order to install the air pipe and electric wire pipe that correspond signal between electric machines for the control system and to reduce the weight of the electric car-body, several circular areas from a cross beam should be taken off. What we want to perform is the optimal design of a cross beam with circular holes to posses equal stress in comparison with no hole cross beam. first, no hole cross beam as basic modal be chosen, executing the analysis, reviewing the distribution of stress and displacement at each location. several parameter should be adopted from the cross beam geometry like the location and shape of the hole to affect the maximum stress and displacement. So the analysis was executed by finite element analysis for finding optimal design parameter to the change of the location and shape of the circular hole. finally, the optimal design of the cross beam with circular holes was obtained and the maximum equivalent stress was compared with no hole cross beam at each location.

• Steel and Composite Structures
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• v.44 no.1
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• pp.141-154
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• 2022

This paper describes the experimental and numerical investigation on circular and octagonal CFDST short columns under concentric loading to study their responses to various internal circular steel tube sizes by the constant cross-sectional dimensions of the external circular and octagonal steel tube. The non-linear finite element analysis of circular and octagonal CFDST columns was executed using the ABAQUS to forecast and compare the axial behavior influenced by the various sizes of internal circular steel tubes. The study shows that the axial compressive strength and ductility of circular and octagonal CFDST columns were significantly influenced by inner steel tubes with the strengths of constituent materials.

• Journal of Korean Society of Water and Wastewater
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• v.21 no.3
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• pp.287-294
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• 2007

When we use the circular pipes for wastewater and storm water, we should be known the characteristics of the flow for accurate design. To elevate the design accuracy, we want to know the profile of flow. The roughness coefficient in the Manning equation is constant, but in actuality changed with the relative depth in circular pipe. This study was conducted to calculate the relative normal depth in changing the roughness coefficient (named relative roughness coefficient) with the relative depth in the analysis of gradually varied flow in the circular pipe by Newton-Raphson method. We performed the analysis of gradually varied flow using the relative normal depth and the relative roughness coefficient. We presented the 12 flow profiles with the relative depth and the relative roughness coefficient in circular pipe. The flow classification considering relative depth in circular pipe is available to analyse gradually varied flow profiles.

• Geomechanics and Engineering
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• v.6 no.4
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• pp.321-340
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• 2014

Uplift response of symmetrical circular anchor plates has been evaluated in physical model tests and numerical simulation using Plaxis. The behavior of circular anchor plates during uplift test was studied by experimental data and finite element analyses in loose sand. Validation of the analysis model was also carried out with 50 mm, 75 mm and 100 mm diameter of circular plates in loose sand. Agreement between the uplift responses from the physical model tests and finite element modeling using PLAXIS 2D, based on 100 mm computed maximum displacements was excellent for circular anchor plates. Numerical analysis using circular anchor plates was conducted based on hardening soil model (HSM). The research has showed that the finite element results gives higher than the experimental findings in the loose sand.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.908-911
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• 2002

This paper investigates the characteristics of deflection for circular plate that has same supporting condition along the width direction of plate according to the area change of supporting end. For two boundary conditions such as simple supporting and clamping on both ends, this study derives maximum deflection formula of circular plate using differential equation of elastic curve, assuming that a circular plate is a beam with different widths along the longitudinal direction. The deflection formula of circular plate is verified by carrying out finite element analysis with regard to the ratio of length of supporting part to radius of circular plate.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.3
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• pp.109-116
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• 2004

This paper investigates the characteristics of deflection for circular plate that has same supporting boundary condition along the width direction of plate according to the length change of supporting end. For two boundary conditions such as simple supporting and clamping on both ends, this study derives maximum deflection formula of circular plate using differential equation of elastic curve, assuming that a circular plate is a beam with different widths along the longitudinal direction. The deflection formula of circular plate is verified by carrying out finite element analysis with regard to the ratio of length of supporting end to radius of circular plate.