• 한국강구조학회 논문집
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• 제9권2호통권31호
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• pp.221-228
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• 1997

이 논문은 일정체적 단순지지 보-기둥의 동적 최적단면의 결정에 관한 연구이다. 정다각형 단면의 단면깊이가 포물선으로 변화하는 보-기둥에 대한 자유진동을 지배하는 상미분방정식을 유도하였다. 이 미분방정식에는 축하중효과를 고려하였고, Runge-Kutta method와 Regula-Falsi method를 이용하여 미분방정식을 수치적분하고 고유진동수를 산출하였다. 수치해석 결과로부터 얻어진 진동수-단면비 곡선의 임계값들을 분석하여 동적 최적단면을 결정하고 이 결과들을 표 및 그림에 나타내었다.

• 한국도서관정보학회지
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• 제14권
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• pp.39-69
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• 1987

The purpose of this research is to analyze the differences between literature (Belles-letters) class in DDC 19 and literature class in KDC 3. The results of the study can be summarized as follows : 1. The section of philosophy and theory of literature in DDC was subdivided according to the properties as including subsection of theory of criticism but KDC didn't subdivide this section. 2. In DDC, the subsections of 'rhetoric in specific languages' and 'rhetoric of specific kinds of composition' in rhetoric section was established and can subdivide according to each languages and subjects. These considerations can be useful as compared with KDC. 3. In DDC, collections or criticism of several literatures in specific forms can be more subdivide according to specific aspects or features dealing with in the collections or criticism by a n.0, pplying Table 3-A when specified more than the literary form. 4. Reviewing a notational rank to be assigned in literatures of specific languages, Latin literature and Classical Greek literature to be ranked in division in DDC was established as subsection in KDC to treat them as literatures of minor languages. 5. The DDC can sometimes a n.0, pply, in literatures of all languages, the notations of Table 3 to be subdivided again as specific kinds of literary forms, but KDC subdivided literary forms as specific kinds of each forms in only Korean, Chinese, Japanese literature. 6. In DDC, even literatures of minor languages are provided with 'the period table for the specific literature' under each literature of specific languages in schedules and these period tables can be a n.0, pplied a n.0, ppropriately, but period numbers in KDC was established in only Korean, Chinese, Japanese literature. 7. The optional use of letter prefixes or special numbers such as 828.99 to distinguish literatures of countries other than the "mother country" which makes the use of period tables feasible, but the KDC can only use to distinguish without the function of dividing a period such as DDC. 8. According to a n.0, pplying Table 3 and 3-A also in literatures of specific languages(810-890), a literature of specific languages, a specific literary form in literature of specific languages and a literature or literary form of specific period, in case of a n.0, pplying 'form divisions 08-09', can subdivide again by a specific aspect or feature dealing with in the works when specified. 9. For grasping the rate of subdividing, after selecting several sample-titles in literary field, they classified by DDC and KDC and gave a definite score in accordance with analytic small subjects. According to the results, the rate of subdividing in literature class of KDC is proved as less 22.8% than DDC. than DDC.

• 대한조선학회논문집
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• 제29권1호
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• pp.1-13
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• 1992

본 논문은 선박의 초기설계와 중앙단면 설계용 지식베이스 시스템을 개발하고 지식공학이 선체구조 설계 분야에 매우 효율적으로 적용될 수 있음을 검토하는데 그 목적이 있다. 이를 위하여 첫째 구조설계에 적합한 지식베이스 전문가 시스템 개발용 도구(tool)인 E.1을 개발하였다. E.1은 C언어로 작성되었고 구조설계 과정을 효율적으로 뒷받침해주기 위해서 자동 반복 계산과 재추론 기능을 갖고 있다. 둘째 살물선의 초기설계시 주요치수 추정과 중앙단면 설계를 위한 지식베이스를 개발하였다. 이 지식베이스들은 통계적 경험식, 선급 규정, 경험적 지식 등을 rule, fact, table로 표현하여 구성하였다. 셋째 지식베이스의 추론을 통하여 중앙 단면 최적 설계 프로그램의 입력 자료를 생성하고 최적화 프로그램을 수행시키는 통합(hybrid) 시스템을 구축하였다. 넷째 보강판 설계용 지식베이스 시스템을 개발하기 위해 최적화 결과의 회귀분석을 이용하는 간이 설계법을 적용해 보았다. 이 시스템을 사용하여 살물선과 보강판의 설계과정을 보이고 그 결과를 검토해 보았다. 앞으로 E.I와 성능 개선과 더 우수한 지식베이스가 축적됨에 따라서 선체 구조설계에 사용되는 기존의 CAD 시스템의 성능이 크게 보완될 것으로 기대된다.

• Steel and Composite Structures
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• 제23권5호
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• pp.597-610
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• 2017

This paper presents a mathematical model for fixed-end moments of I-sections with straight haunches for the general case (symmetrical and/or non-symmetrical) subjected to a concentrated load localized anywhere on beam taking into account the bending deformations and shear, which is the novelty of this research. The properties of the cross section of the beam vary along its axis "x", i.e., the flange width "b", the flange thickness "t", the web thickness "e" are constant and the height "d" varies along of the beam, this variation is linear type. The compatibility equations and equilibrium are used to solve such problems, and the deformations anywhere of beam are found by the virtual work principle through exact integrations using the software "Derive" to obtain some results. The traditional model takes into account only bending deformations, and others authors present tables considering the bending deformations and shear, but are restricted. A comparison between the traditional model and the proposed model is made to observe differences, and an example of structural analysis of a continuous highway bridge under live load is resolved. Besides the effectiveness and accuracy of the developed models, a significant advantage is that fixed-end moments are calculated for any cross section of the beam "I" using the mathematical formulas.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2000년도 봄 학술발표회논문집
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• pp.92-99
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• 2000

The nondimensional differential equations governing the buckling loads of tapered columns with both clamped ends and its boundary conditions are derived, in which the effects of shear deformations are included. These equations are solved numerically using a numerical integration technique and a bracketing method to obtain the buckling loads of columns. Four types of cross-sectional shape are considered in the numerical examples. The parametric studies of shear deformation effects on the buckling loads such as cross-sectional shape factor, shear coefficient, ratio of modulus of elasticity, slenderness ratio and section ratio are reported in tables and figures.

• Advances in nano research
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• 제9권2호
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• pp.91-104
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• 2020

The bending, stability (buckling) and vibration response of nano sized beams is presented in this study based on the Eringen's nonlocal elasticity theory in conjunction with the Euler-Bernoulli beam theory. For this purpose, the bending, buckling and vibration problem of Euler-Bernoulli nanobeams are developed and solved on the basis of nonlocal elasticity theory. The effects of various parameters such as nonlocal parameter e₀a, length of beam L, mode number n, distributed load q and cross-section on the bending, buckling and vibration behaviors of carbon nanotubes idealized as Euler-Bernoulli nanobeam is investigated. The transverse deflections, maximum transverse deflections, vibrational frequency and buckling load values of carbon nanotubes are given in tables and graphs.

• 한국농공학회지
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• 제36권4호
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• pp.56-63
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• 1994

The nondimensional differential equations governing the buckling loads of tapered columns and its houndarv conditions are derived, in which the effects of shear deformations are included. These equations are solved numerically using a numerical integration technique and a bracketing method to obtain the buckling loads of columns. Four types of cross-sectional shape with clamped-free end constraint are used in the numerical examples. The parametric studies of shear deformation effects on the buckling loads such as cross-sectional shape factor, shear coefficient, ratio of modulus of elasticity, slenderness ratio and section ratio are reported in tables and figures.

• 한국소음진동공학회논문집
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• 제16권10호
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• pp.1074-1081
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• 2006

This paper deals with the dynamic stability analysis of clamped-hinged columns with constant volume. Numerical methods are developed for solving natural frequencies and buckling loads of such columns, subjected to an axial compressive load. The parabolic taper with the regular polygon cross-section is considered, whose material volume and column length are always held constant. Differential equations governing both free vibrations and buckled shapes of such columns are derived. The Runge-Kutta method is used to integrate the differential equations, and the Regula-Falsi method is used to determine natural frequencies and buckling loads, respectively. The numerical methods developed herein for computing natural frequencies and buckling loads are found to be efficient and robust. From the numerical results, dynamic stability regions, dynamic optimal shapes and configurations of strongest columns are reported in figures and tables.

• Structural Engineering and Mechanics
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• 제22권2호
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• pp.131-150
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• 2006

Exact analytical solutions for in-plane static problems of planar curved beams with variable curvatures and variable cross-sections are derived by using the initial value method. The governing equations include the axial extension and shear deformation effects. The fundamental matrix required by the initial value method is obtained analytically. Then, the displacements, slopes and stress resultants are found analytically along the beam axis by using the fundamental matrix. The results are given in analytical forms. In order to show the advantages of the method, some examples are solved and the results are compared with the existing results in the literature. One of the advantages of the proposed method is that the high degree of statically indeterminacy adds no extra difficulty to the solution. For some examples, the deformed shape along the beam axis is determined and plotted and also the slope and stress resultants are given in tables.

• Structural Engineering and Mechanics
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• 제54권3호
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• pp.419-432
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• 2015

The free vibration of rotating Euler-Bernoulli beams with the thickness and/or width of the cross-section vary linearly along the length is investigated by using the Adomian modified decomposition method (AMDM). Based on the AMDM, the governing differential equation for the rotating tapered beam becomes a recursive algebraic equation. By using the boundary condition equations, the dimensionless natural frequencies and the closed form series solution of the corresponding mode shapes can be easily obtained simultaneously. The computed results for different taper ratios as well as different offset length and rotational speeds are presented in several tables and figures. The accuracy is assured from the convergence and comparison with the previous published results. It is shown that the AMDM provides an accurate and straightforward method of free vibration analysis of rotating tapered beams.