• Journal of the Korean GEO-environmental Society
• /
• v.15 no.8
• /
• pp.51-58
• /
• 2014

In this research, the composite grounds including original clay and soil-cement were constructed for conducting uniaxial compression test. Strength and deformation properties were analysed using results of laboratory tests with variations of water content of clay, replacement ratio and cement content. Numerical simulation using 3D distinct element method was conducted for soil cement. For strength of composite ground that contains more than cement contents of 15 %, it is more effective to increase cement content than increase of replacement ratio. Strength and elastic modulus of composite ground could be predicted by regression equations using uniaxial compression strength of clay, cement content of soil cement and replacement ratio. For strength and elastic modulus of soil cement, which is most important things for predicting final strength and elastic modulus of composite ground, numerical simulation using the distinct element method adapted bonding model could be used to verify laboratory test, and predict strength and elastic modulus.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.14 no.1
• /
• pp.89-93
• /
• 2008

Stiffened panels are basic strength members which have been used widely in a vessel or an offshore. They have been used often a deck, a side and a bottom structure of ship and have a number of one sided stiffener in either one or both directions called grillage. Their buckling and plastic collapse become damaged reason of the hull girder so it needs to investigate accurately buckling and ultimate strength of stiffened panels. In the present paper, using the ANSYS, a commercial finite element analysis code, we conducted the evaluation regarding buckling and post-buckling behaviour of stiffened panels, and analyzed stiffener's web height change, considering the effect of lateral pressure load against compression ultimate strength.

• Journal of the Society of Naval Architects of Korea
• /
• v.33 no.3
• /
• pp.8-21
• /
• 1996

The aim of this study is to derive an empirical formula for predicting ultimate strength of plates and stiffened plates subjected to uniaxial compression. The test data of ultimate compressive strength for unstiffened and stiffened plates previously obtained by others have been collected. Many test data are necessary so that the derived formula will be available in wide range of plate dimensions. Additional collapse tests for a plate specimen with one flat bar stiffener, varying dimensions of plate and stiffener were performed in this study. On the basis of the present and previous experimental data, a more useful empirical formula than the existing ones was derived by applying the least square method.

• Proceedings of KOSOMES biannual meeting
• /
• 2005.05a
• /
• pp.141-146
• /
• 2005

Ship have cutout inner bottom and girder and floor etc. Ship's structure is used much, and structure strength must be situated, but establish new concept when high stress interacts sometimes fatally the area. There is no big problem usually by aim of weight reduction, a person and change of freight, piping etc. Because cutout's existence grow up in this place, and, elastic buckling strength by load causes large effect in ultimate strength. Therefore, stiffened perforated plate considering buckling strength and ultimate strength is one of important design criteria which must examine when decide structural concept at initial design. Therefore, and, reasonable buckling strength about perforated stiffened plate need to ultimate strength limited design . Calculated ultimate strength varied several web height and cutout's dimension, and thickness in this investigated data. Used program(ANSYS) applied F.E.A code based on finite element method.

• Magazine of the Korea Concrete Institute
• /
• v.11 no.2
• /
• pp.157-165
• /
• 1999

When the ultimate strength of a concrete flexural member is evaluated, the effect of member size is usually not considered. For various types of loading, however, the strength always decreases with the increment of member size. In this paper the size effect of a flexural compression member is investigated by experiments. For this purpose, a series of C-shaped specimens subjected to axial compressive load and bending moment was tested using three different sizes of specimens with a compressive strength of 528 kg/$cm^2$. According to test results the size effect on flexural compressive strength was apparent, and more distinct than that for uniaxial compressive strength of cylinders. Finally a model equation was derived using regression analyses with experimental data.

• Journal of Welding and Joining
• /
• v.8 no.4
• /
• pp.69-75
• /
• 1990

In this paper, ultimate compressive strength of TMCP 50HT steel plates (yield stress .sigma.$_{o}$=36kg/mm$^{2}$) with HAZ softening is studied. Finite element method formulated by the author is applied to analyze the elasto-plastic large deflection behaviour of the plates. The influence of HAZ softening breadth, welding direction and slenderness ratio on the ultimate compressive strength is investigated. The results obtained are summarized as 1) With the increasing of the HAZ softening breadth, early plasticity on the plates is formed and then the ultimate compressive strength is decreased, in which about 8% of the ultimate strength for the plate with h/t=4(h: HAZ softening breadth, t: plate thickness) was reduced comparing with no HAZ softening. 2) The large decrease of the ultimate strength for the case that the welding direction is normal to the loading direction is occurred than the case that the welding direction is parallel to the loading direction. 3) The influence of HAZ softening on the ultimate compressive strength is serious for thick plates, while it may be negligible for thin plates.s.

• Journal of the Society of Naval Architects of Korea
• /
• v.28 no.1
• /
• pp.117-124
• /
• 1991

In this paper, a method to overcome inefficiency of the finite element method in the calculation of compressive strength of one-sided stiffened plates, is proposed. In this method the collapse modes of stiffened plates are assumed as follows. a) Overall buckling $\rightarrow$ Overall collapse b) Local buckling $\rightarrow$ Overall collapse c) Local buckling $\rightarrow$ Local collapse In each collapse mode, shape of deflection is assumed, and then elastic large deformation analysis based on the Rayleigh-Ritz method is carried out. One-sided stiffening effect is considered by taking into account of the moment due to eccentricity. Plastic analysis by assuming hinge lines is also carried out. The ultimate strength of a stiffened plate is obtained as the point of intersection of the elastic analysis curve and the plastic one. From this study, it is concluded that the angles between the plastic hinge lines in plastic collapse mode are determined as the ones which give the minimum collapse load, and these angles are different from the ones assumed in the previous studies. Minimum stiffness ratios can also be calculated. Calculated results according to this method show good agreements with the results by the finite element method.

• Journal of the Korea Concrete Institute
• /
• v.25 no.5
• /
• pp.573-581
• /
• 2013

In this paper, an experimental investigation of bond properties between steel fiber reinforced concrete and glass fiber reinforced polymer reinforcements was performed. The experimental variables were diameter of reinforcements, volume fraction of steel fiber, cover thickness and compressive strength of concrete. Bond failure mainly occurred with splitting of concrete cover. Main factor for splitting of concrete is tension force occurred by the displacement difference between reinforcements and concrete. Therefore, in order to prevent the bond failure between reinforcements and concrete, capacity of tensile strength of concrete cover should be upgraded. As a results of test, volume fraction of steel fiber significantly increases the bond strength. Cover thickness changes the failure mode. Diameter of reinforcements also changes the failure mode. Generally, diameter of reinforcement also affects the bond properties but this effect is not significant as volume fraction of fiber. Increase of compressive strength increases the bond strength between concrete and reinforcement because compressive strength of concrete directly affects the tensile strength of concrete.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2005.05a
• /
• pp.383-386
• /
• 2005

철근콘크리트 부재가 하중을 받을 때, 응력교란구역에서의 힘의 흐름은 스트럿-타이 모델을 이용하여 효과적으로 표현할 수 있다. 그러나 스트럿-타이 모델을 이용하여 철근콘크리트 부재의 해석과 설계를 하기 위해서는 큰크리트 압축스트럿이 가지는 유효강도를 정확히 산정하여야 한다. 본 연구는 철근콘크리트 부재에 휨과 전단력이 동시에 작용할 때 발생하는 대각선 균열이 콘크리트 압축스트럿에 미치는 영향에 대해 설명하고 있다. 대각선 균열의 발생 메커니즘과 이로 인한 콘크리트 압축스트럿의 강도 저하를 이론적으로 설명하였으며, 그 결과를 철근콘크리트 보의 강도 산정에 적용하였다. 최종적으로 철근콘크리트 보의 강도 예측값을 기존 연구자들의 실험결과와 비교하여 제안된 이론의 합리성을 검증하였다.

• Proceedings of the KWS Conference
• /
• 1990.04a
• /
• pp.94-96
• /
• 1990