• International Journal of Naval Architecture and Ocean Engineering
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• 제7권2호
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• pp.399-408
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• 2015

This paper concentrated on the ultimate uniaxial compressive strength of stiffened panel with opening under lateral load and also studied the design-oriented formulae. For this purpose, three series of well executed experiments on longitudinal stiffened panel with rectangular opening subjected to the combined load have been selected as test models. The finite element analysis package, ABAQUS, is used for simulation with considering the large elasticplastic deflection behavior of stiffened panels. The feasibility of the numerical procedure is verified by a good agreement of experimental results and numerical results. More cases studies are executed employing nonlinear finite element method to analyze the influence of design variables on the ultimate strength of stiffened panel with opening under combined pressure. Based on data, two design formulae corresponding to different opening types are fitted, and accuracy of them is illustrated to demonstrate that they could be applied to basic design of practical engineering structure.

• 한국강구조학회 논문집
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• 제26권4호
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• pp.277-288
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• 2014

본 연구에서는 여러 가지 제원 변화에 따른 폐단면 리브 보강판의 국부 처짐과 국부 모멘트의 특성을 살펴보고자 하였다. 여러가지 사다리꼴 리브를 갖는 보강판에 정사각형 분포하중을 재하하고 분석한 결과, 재하 패널 폭이 국부 거동에 미치는 영향이 가장 큰 것으로 나타났으며, 옆 패널 폭이 미치는 영향은 매우 작은 것을 알 수 있었다. 또한, 기준 보강판의 국부 거동은 강판과 리브가 이루는 각도로 표현되고, 다른 보강판의 국부 거동은 기준값에 재하 패널 폭, 판 두께, 리브 두께, 리브 높이, 옆 패널 폭의 비율 함수를 곱하여 구할 수 있음을 알 수 있었으며, 결과 또한 상당한 정확도를 나타내었다. 비율 함수를 다른 재하 크기에 적용한 결과, 재하 패널 폭을 제외한 다른 비율 함수의 타당성을 확인할 수 있었으며, 재하 패널 폭의 함수를 보정한 결과, 오차율이 크게 개선되었다. 따라서 본 연구에서 제안한 비율 함수식을 이용하면, 제원과 상관없이 폐단면 리브를 갖는 보강판의 국부 처짐과 국부 모멘트에 대하여 간편하게 타당한 결과를 얻을 수 있을 것으로 판단된다.

• 한국군사과학기술학회지
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• 제23권6호
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• pp.533-541
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• 2020

This study using ABAQUS investigates the nonlinear vibration responses when thermal and random acoustic loads are applied simultaneously to the stiffened composite panels. The nonlinear vibration analyses are performed with changing the number of stiffeners, and layup condition of the skin panel. The panel and stiffeners both are modeled using shell elements. Thermal load (ΔT) is assumed to have the temperature gradient through the thickness direction of the stiffened composite panel. The random acoustic load is represented as stationary white-Gaussian random pressure with zero mean and uniform magnitude over the panels. The thermal postbuckling analysis is conducted using RIKS method, and the nonlinear dynamic analysis is performed using Hilber-HughesTaylor time integration method. When ΔT = 25.18 ℃ and SPL = 105 dB are applied to the stiffened composite panel, the effect of the number of stiffener is investigated, and the snap-through responses are observed for composite panels without stiffeners and with 1 and 3 stiffeners. For investigation of the effect of layup condition of the skin panel, when ΔT = 38.53 ℃ and SPL = 110 dB are applied to the stiffened composite panel, the snap-through responses are shown when the fiber angle of the skin panel is 0°, 30°, and 60°.

• 대한조선학회논문집
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• 제52권2호
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• pp.161-169
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• 2015

According to SOLAS Regulation XII/6.5.3 and IMO GBS functional requirement(IMO, 2010), the structural redundancy of multi-bay stiffened panel in cargo area of bulk carrier should be provided enough in order to endure the initial design load though one bay of the stiffened panel is damaged due to plastic deformation or fatigue crack. To satisfy structural redundancy, Harmonized Common Structural Rules (hereinafter CSR-H, IACS, 2014) proposed to use 1.15 instead of 1.0 for buckling usage factor of stiffened panel in cargo area. This paper shows that buckling usage factor in CSR-H for structural redundancy is somewhat conservative considering the ultimate strength calculated by using nonlinear FEA for the damaged condition which is only one bay's plastic deformation due to colliding by weigh object like a bucket. Also, this paper presents that increasing of plate thickness only is more effective to get enough structural redundancy.

• 한국농촌건축학회논문집
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• 제7권1호
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• pp.129-136
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• 2005

In this paper, barrier panels against falling stones have been studied experimentally with various specimens. Test results show that stiffened barrier panels show more sufficient capacity than unstiffened barrier. Each type barrier panel can be used for various situations. New barrier panel is good for increasing strength and improving environment and maintaining cost down.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2009년도 춘계학술대회 논문집
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• pp.779-780
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• 2009

• 한국공작기계학회논문집
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• 제12권5호
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• pp.88-93
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• 2003

Buckling behavior of stiffened laminated composite cylindrical panel was studied using linear and nonlinear deformation theory. Various buckling load factors are obtained for stiffened laminated composite cylindrical panels with rectangular type longitudinal stiffeners and various longitudinal length to radius ratio, which made from Carbon/Epoxy USN150 prepreg and are simply-supported on four edges under uniaxial compression. Buckling behavior design analyses are carried out by the nonlinear search optimizer, ADS.

• International Journal of Naval Architecture and Ocean Engineering
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• 제12권1호
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• pp.699-710
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• 2020

Pitting corrosion commonly shaped in hull structure due to marine corrosive environment seriously causes the deterioration of structural performance. This paper deals with the ultimate strength behaviors of stiffened ship panels damaged by the pits subjected to uniaxial compression. A series of no-linear finite element analyses are carried out for three stiffened panels using ABAQUS software. Influences of the investigated typical parameters of pit degree (DOP), depth, location and distribution on the ultimate strength strength are discussed in detail. It is found that the ultimate strength is significantly reduced with increasing the DOP and pit depth and severely affected by the distribution. In addition, the pits including their distributions on the web have a slight effect on the ultimate strength. Compared with regular distribution, random one on the panel result in a change of collapse mode. Finally, an empirical formula as a function of corrosion volume loss is proposed for predicting the ultimate strength of stiffened panel.

• 한국정밀공학회지
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• 제17권4호
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• pp.197-202
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• 2000

A simple numerical procedure is presented to determine the stress intensity factors for crack in a stiffened panel subjected to a uniaxial uniform stress normal to the crack. Two types of stiffened panels are analyzed by the finite element method for various values of crack lengths, stiffness ratios, and stiffener spacings. From the finite element solution, the stress intensity factors were determined by using hybrid extrapolation method. Results are presented in graphical forms for upper mentioned parameters.

• Composites Research
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• 제35권4호
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• pp.269-276
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• 2022

본 연구에서는 층간분리의 위험이 없는 3차원 직조방식으로 복합재 보강패널을 제작하고 좌굴하중과 고유진동수 등의 기계적 특성을 연구하였다. 보강패널의 스트링거와 외피는 일체형으로 제작하였고 T800급 탄소섬유로 만들어진 프리폼에 수지(EP2400)를 충진시키는 방식을 적용하였다. 제작된 보강판에 대하여 압축시험과 고유진동수 측정 시험을 수행하였고 유한요소해석 결과와 비교하였다. 또한 3차원 직조 구조물의 성능을 상대적으로 비교하기 위해 일방향 프리프레그와 2차원 평직(fabric)으로 동일한 치수의 보강패널을 제작하여 시험과 해석을 수행하였다. 시험값을 기준으로 일방향 프리프레그와 2차원 평직으로 제작된 보강패널의 좌굴하중은 3차원 직조 패널의 좌굴하중 대비 각각 20%, -3%의 차이를 보였다. 본 연구로부터 3차원 직조방식으로 제작된 일체형 보강패널의 좌굴하중은 일방향 프리프레그 적층 보강판의 좌굴하중보다는 낮지만 2차원 평직 보강판넬보다는 미세하게 높은 수준의 값을 보임을 확인하였다.