• 대한토목학회논문집
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• 제29권2A호
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• pp.145-153
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• 2009

본 연구에서는 포물선 아치의 횡-비틂 좌굴 강도에 관한 연구를 수행하였다. 포물선 아치는 아치의 중립축을 따라 곡률이 변하므로 일정한 곡률을 갖는 원형 아치의 경우보다 횡-비틂 좌굴 강도식을 유도하는 것이 복잡하며, 이에 대한 연구가 미흡한 실정이다. 본 연구에서는 ?의 효과를 고려하여 변곡률을 갖는 아치의 횡-비틂 좌굴식을 유도하고 포물선 아치의 좌굴강도를 계산하기 위하여 유한차분법을 이용한 수치해법을 제안하였다. 이러한 수치해법은 기존 연구자 및 유한요소해석 결과와 비교하였으며, 그 타당성을 검증하였다. 마지막으로, 변수해석을 수행하여 라이즈비의 영향에 따른 원형과 포물선 아치의 횡-비틂 좌굴 강도를 비교 분석하였다.

• 한국강구조학회 논문집
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• 제18권3호
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• pp.301-310
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• 2006

면외로 적절히 구속되어 있는 아치의 극한강도는 소성 휨모멘트와 면내 연구는 압축력을 받는 고정지점 포물선 아치의 면내 좌굴 거동과 강도에 관한 연구를 수행하고, 압축력과 휨모멘트를 받는 고정지점 포물선 아치로 연구를 확장하였다. 본 연구 결과 한계 세장비를 제안하여 아치의 좌굴 모드를 구분하는 방법을 제안하였으며, 직선기둥의 좌굴곡선을 이용하여 압축력을 받는 고정지점 포물선 아치의 극한하중을 평가하였다. 마지막으로 직선 부재의 보-기둥 연성식을 수정하여 고정지점을 갖는 포물선 아치에 적용하였다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 추계학술대회논문집 II
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• pp.995-999
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• 2001

This paper deals with the free vibrations of arches with general boundary condition. Based on the dynamic equilibrium equations of a arch element acting the stress resultants and the inertia forces, the governing differential equation is derived for the in-plane free vibration of such arches. Differential equations are solved numerically to calculate natural frequencies. In numerical examples, the parabolic arch is considered. The effects of the arch rise to span length ratio, the slenderness ratio, the vertical spring coefficient and the rotational spring coefficient on the natural frequencies are analyzed.

• 대한토목학회논문집
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• 제6권3호
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• pp.1-9
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• 1986

동하중(動荷重)을 받는 양단(兩端) 힌 지 포물선(抛物線) 아치의 연동방정식(連動方程式)을 Runge-Kutta 방법(方法)으로 수치해석(數値解析)하므로써 동적(動的) 임계하중(臨界荷重)을 구했다. 낮은 양단(兩端) 힌 지 포물선(抛物線) 아치에 step하중(荷重)과 impulse하중(荷重))이 작용(作用)하는 경우에 관해 Budiansky-Roth criterion을 적용하여 동적(動的) 임계하중(臨界荷重)을 정의(定義)하고, 이를 상관곡선(相關曲線)으로써 동적(動的) 안정영역(安定領域)을 제안하였다. 포물선(抛物線) 아치에 대하여 얻어진 결과를 정현(正弦) 아치의 경우와 비교(比較)하여 아치의 기하학적(幾何學的) 형상(形狀)이 동적(動的) 안정영역(安定領域)에 미치는 영향을 밝혔고, 동적(動的) 안정영역(安定領域)은 아치의 높이에 큰 영향을 받는다는 것을 밝혔다.

• 한국농공학회지
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• 제28권2호
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• pp.87-92
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• 1986

The differential equation, which can determine the dynamic critical loads for low parabcoic arches, is derived in this study. The dynamic critical loads of the parabolic arches subjected to a concentrated step load are nummerically analyzed for the changes of load positions. In cases of arches with different end conditions (both hinged, fixed hinged, both fixed), the effect of end conditions and that of the rises are investigated in detail. The summary of the results are the following: 1)The snapthrough does not occur when the rise of arch is very low, and the bifurcation appears clearly as the rise of arch increases. 2)The regions in which the dynamic critical loads are not defined for the both ends fixed are broader than that for the both ends hinged. 3)For all case, the load positions of minimum dynamic critical loads exsit at the near position from the end hinged. Thus, the results obtained in present study show that the magnitude of dynamic critical loads, the load positions of minimum dynamic critical loads and the regions in which the dynamic critical loads are not defined depend on end conditions of arches.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 추계학술대회논문집
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• pp.819-823
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• 2003

The differential equations governing the shape of displacement for the shallow parabolic arch subjected to multiple dynamic point step loads were derived and solved numerically The Runge-Kutta method was used to perform the time integrations. Hinged-hinged end constraint was considered. Based on the Budiansky-Roth criterion, the dynamic critical point step loads were calculated and the dynamic stability regions for such loads were determined by using the data of critical loads obtained in this study.

• 한국농공학회지
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• 제28권1호
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• pp.68-74
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• 1986

The governing differential equations and the boundary conditions for the free vibra- tion of the unsymmetric parabolic arch with fixed ends are derived on the basis of the equilibrium equations and the D'Alembert principle. The effect of the rotary inertia as well as the extensional and the flexural deformations is considered in the governing differential equations. A trial eigenvalue method is used for determining the natural frequencies. The Ru- uge-Kutta method is used in this method to perform the integration of the differential equations. The detailed studies are made of the lowest three vibration frequencies for the par- abolic chord length equal to 10m. The effect of the rotary inertia is analyzed and it's numerical data are presented in table. And as the numerical results the frequency versus the rise of arch and the radius of gyration are presented in figures.

• Steel and Composite Structures
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• 제34권1호
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• pp.1-15
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• 2020

This paper presents experimental and numerical studies on effects of local damages on the in-plane elastic-plastic buckling and strength of a fixed parabolic steel tubular arch under a vertical load distributed uniformly over its span, which have not been reported in the literature hitherto. The in-plane structural behaviour and strength of ten specimens with different local damages are investigated experimentally. A finite element (FE) model for damaged steel tubular arches is established and is validated by the test results. The FE model is then used to conduct parametric studies on effects of the damage location, depth and length on the strength of steel arches. The experimental results and FE parametric studies show that effects of damages at the arch end on the strength of the arch are more significant than those of damages at other locations of the arch, and that effects of the damage depth on the strength of arches are most significant among those of the damage length. It is also found that the failure modes of a damaged steel tubular arch are much related to its initial geometric imperfections. The experimental results and extensive FE results show that when the effective cross-section considering local damages is used in calculating the modified slenderness of arches, the column bucking curve b in GB50017 or Eurocode3 can be used for assessing the remaining in-plane strength of locally damaged parabolic steel tubular arches under uniform compression. Furthermore, a useful interaction equation for assessing the remaining in-plane strength of damaged steel tubular arches that are subjected to the combined bending and axial compression is also proposed based on the validated FE models. It is shown that the proposed interaction equation can provide lower bound assessments for the remaining strength of damaged arches under in-plane general loading.

• 소음진동
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• 제10권2호
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• pp.353-360
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• 2000

Numerical methods are developed for calculating the natural frequencies and mode shapes of the tapered cantilever arches with variable curvature. The differential equations governing the free vibrations of such arches are derived and solved numerically, in which the effect of rotatory inertia is included. The parabolic shape is chosen as the arch with variable curvature while both the prime and quadratic arched members are considered as the tapered arch with variable curvature while both the prime and quadratic arched members are considered as the tapered arch. Comparisons the natural jfrequencies between this study and finite element method SAP 90 seve to validate the numerical method developed herein. The lowest four natural frequencies are reported as a function of four non-dimensional system parameters. The effects of both the rotatory inertia and cross-sectional shape are reported. Also, the typical mode shapes of stress resultants as well as the displacements are reported.

• 한국강구조학회 논문집
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• 제17권4호통권77호
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• pp.439-447
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• 2005

아치 리브가 수직 하중을 받는 경우, 예기치 않게 면내 방향으로 좌굴이 발생될 수 있다. 따라서 설계자는 아치 리브의 면내 안정성을 설계 시 반드시 고려해야 한다. 본 논문에서는 유한 요소 해석을 통하여 수직 등분포 하중을 받는 고정지점 포물선 아치 리브의 탄성, 비탄성 면내 좌굴 강도를 연구하였다. 본 연구에서 사용된 아치 리브의 스냅-스루 현상과 비탄성 거동을 모사하기 위한 유한 요소 해석 모델은 기존 연구자들의 실험 결과를 이용하여 검증되었다. 또한 아치 리브의 면내 극한 강도를 결정하기 위하여 대변형과 재료의 비탄성, 잔류응력을 고려하였으며, 마지막으로 유한 요소 해석의 결과를 EC3 설계기준과 비교, 분석 하였다.