• 한국해양공학회지
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• 제36권4호
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• pp.243-250
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• 2022

Subsea power cables are subjected to various external loads induced by environmental and mechanical factors during manufacturing, shipping, and installation. Therefore, the prediction of the structural strength is essential. In this study, experimental and theoretical analyses were performed to investigate the axial stiffness of subsea power cables. A uniaxial tensile test of a 6.5 m three-core AC inter-array subsea power cable was carried out using a 10 MN hydraulic actuator. In addition, the resultant force was measured as a function of displacement. The theoretical model proposed by Witz and Tan (1992) was used to numerically predict the axial stiffness of the specimen. The Newton-Raphson method was employed to solve the governing equation in the theoretical analysis. A comparison of the experimental and theoretical results for axial stiffness revealed satisfactory agreement. In addition, the predicted axial stiffness was linear notwithstanding the nonlinear geometry of the subsea power cable or the nonlinearity of the governing equation. The feasibility of both experimental and theoretical framework for predicting the axial stiffness of subsea power cables was validated. Nevertheless, the need for further numerical study using the finite element method to validate the framework is acknowledged.

• 한국공간구조학회논문집
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• 제10권2호
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• pp.69-76
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• 2010

적층고무 면진장치의 전단강성 뿐만 아니라 인장강성 및 압축강성을 실험적으로 구한 후 비선형 해석 프로그램을 이용하여 면진장치를 모델링 하였다. 수평력을 받는 면진된 골조의 면진장치에 전도에 의한 인장응력이 발생되게 하기 위하여 큰 초기변위를 부여한 자유진동 실험을 해석적으로 수행하였다. 적층고무 면진장치는 인장에 약하기 때문에 면진장치에서의 들림 현상을 해석적으로 구하기 위하여 면진장치의 수직방향 강성들이 해석 모델에 적절히 반영되어야 한다.

• Structural Engineering and Mechanics
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• 제19권3호
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• pp.337-346
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• 2005

The paper reports on a study of bond strength between reduced-water-content concrete and tensile reinforcement in spliced mode. Three different diameters (12, 16 and 22 mm) of tensile steel were spliced in the constant moment zone, where there were two bars of same size in tension. For each diameter of reinforcement, a total of nine beams ($1900{\times}270{\times}180mm$) were tested, of which three beams were with no axial force (positive bending) and the other six beams were with axial force (combined bending). The splice length was selected so that bars would fail in bond, splitting the concrete cover in the splice region, before reaching the yield point. It was found that there was a considerable size effect in the experimental results, i.e., as the diameter of the reinforcement reduced the bond strength and the deflection recorded at the midspan increased significantly, whilst the stiffness of the beams reduced. It was also found for all reinforcement sizes that higher bond strength and stiffness were obtained for beams tested in combined bending than that of the beams tested in positive bending only.

• Steel and Composite Structures
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• 제21권1호
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• pp.137-156
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• 2016

Due to excellent advantages such as better illuminative effects, considerable material savings and ease and rapidness of construction, the bolted ball-cylinder joint which is a new type joint system has been proposed in space truss structures. In order to reveal more information and understanding on the behaviour of bolted ball-cylinder joints, full-scale experiments on eight bolted ball-cylinder joint specimens were conducted. Five joint specimens were subjected to axial compressive force, while another three joint specimens were subjected to axial tensile force. The parameters investigated herein were the outside diameter of hollow cylinders, the height of hollow cylinders, the thickness of hollow cylinders, ribbed stiffener and axial force. These joint specimens were collapsed by excessive deformation of hollow cylinders, punching damage of hollow cylinders, evulsion of bolts, and weld cracking. The strain distributions on the hollow cylinder opening were mainly controlled by bending moments. To improve the ultimate bearing capacity and axial stiffness of bolted ball-cylinder joints, two effective measures were developed: (1) the thickness of the hollow cylinder needed to be thicker; (2) the ribbed stiffener should be adopted. In addition, the axial stiffness of bolted ball-cylinder joints exhibited significant non-linear characteristics.

• Steel and Composite Structures
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• 제16권2호
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• pp.157-185
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• 2014

This paper examines the behaviour of two types of practical open beam-to-tubular column connection details subjected to combined moment, axial and/or shear loads. Detailed continuum finite element models are developed and validated against available experimental results, and extended to deal with flexural, axial and shear load interactions. A numerical investigation is then carried out on the behaviour of selected connections with different stiffness and strength characteristics under various load combination scenarios. The influence of applied levels of axial tensile or compressive loads on the bending stiffness and capacity is examined and discussed. Additionally, the interaction effects between shear forces and co-existing bending and axial loads are examined and shown to be comparatively insignificant in terms of stiffness and capacity in most cases. It is also shown that the range of connections considered in this paper can provide rotational ductility levels in excess of those required under typical design scenarios. Based on these findings, a simplified component-based representation is proposed and described, and its ability to represent the connection response under combined loading is verified using results from detailed numerical simulations.

• 한국강구조학회 논문집
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• 제27권2호
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• pp.251-260
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• 2015

단부판 접합부는 다양한 형태로 보-기둥 모멘트 접합부에 적용되고 있다. 이러한 단부판 접합부는 단부판의 두께 및 길이, 고장력 볼트의 개수 및 직경, 고장력볼트의 게이지 거리, 고장력볼트의 지레작용력, 용접부의 치수 및 길이 등에 따라서 상이한 거동특성, 강성 및 강도, 에너지소산능력의 변화를 나타낸다. 따라서 이 연구는 단부판의 두께 변화에 따른 인장측에 체결된 고장력볼트의 지레작용력 및 축방향 인장강성을 파악하고, 단부판의 거동특성에 영향을 미치는 이러한 변수들을 예측하기 위한 해석모델을 제안하기 위하여 진행하였다. 이를 위하여 이 연구에서는 단부판의 두께만을 변수로 선택하여 비보강 확장단부판 접합부에 대한 3차원 비선형 유한요소해석을 수행하였다.

• Structural Engineering and Mechanics
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• 제73권2호
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• pp.123-132
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• 2020

Steel spherical hinged bearings have high loading capacity, reliable load transfer, flexible rotation with universal hinge and allowance of large displacement and rotation angle. However, bearings are in complex forced states subject to various load combinations, which lead to the significant influence on integral structural safety. Taking the large-tonnage complex steel spherical hinged bearings of Terminal 2 of Guangzhou Baiyun International Airport as an example, full-scale rotation and shear behaviour tests of the bearings subject to axial tensile load are carried out, and the corresponding finite element simulation analyses are conducted. The results of experiments and finite element simulations are in good agreement with the coincident development tendency of stress and deformation. In addition, the measured rotational moment is less than the calculated moment prescriptive by the code, and the relationship between horizontal displacement and horizontal shear force is linear. Finally, based on these results, the rotation and shear stiffness models of bearings subject to axial tensile load are proposed for the refinement analysis of integral structure.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 추계 학술발표회 논문집
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• pp.81-84
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• 2006

The purpose of this study is to investigate the inelastic behavior of hollow reinforced concrete bridge piers under varying axial load. The role of the variable axial load is very important in the ductility, strength, stiffness, and energy dissipation. A computer program, named RCAHEST(Reinforced Concrete Analysis in Higher Evaluation System Technology), for the analysis of reinforced concrete structures was used. Material nonlinearity is taken into account by comprising tensile, compressive and shear models of cracked concrete and a model of reinforcing steel. The proposed numerical method for the inelastic behavior of hollow reinforced concrete bridge piers under varying axial load is verified by comparison with reliable experimental results.

• 한국강구조학회 논문집
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• 제19권2호
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• pp.201-210
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• 2007

더블앵글 접합부는 충분한 강성 및 강도를 갖추어 작용하중을 잘 지탱할 수 있도록 설계되어야 한다. 따라서 구조설계자는 더블앵글 접합부의 강성 및 강도에 영향을 미치는 여러 변수들을 파악하여 접합부 설계에 반영하여야 한다. 본 연구는 볼트 게이지 거리 및 볼트 개수 등의 변수가 축방향 인장력을 받는 더블앵글 접합부의 강성 및 강도에 미치는 영향을 파악하기 위하여 진행하였다. 이를 위하여 6개의 접합부 시험체를 제작하여 접합부 실험을 수행하였고, 접합부의 하중-변위 관계 곡선을 획득하였다. 또한, 접합부 실험결과를 바탕으로 축방향 인장력을 받는 더블앵글 접합부의 초기강성 및 설계하중을 예측할 수 있는 해석모델도 제안하였다. 이러한 접합부 강성 및 강도 예측모델은 지렛대 작용 효과의 영향도 고려하여 제안되었다.

• Structural Engineering and Mechanics
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• 제90권5호
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• pp.435-446
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• 2024

The use of cold-formed steel members is increasing day by day, especially in regions where earthquake effects are intensively experienced. Among cold-formed steel members (CFS), "channel" members are used more than other crosssectional members, especially in buildings or industrial structures. In recent years, several studies have been carried out on the axial load and flexural performance of these members under monotonic loading. In this study, CFS beam-column members were cyclically and monotonically loaded under combined axial load and biaxial bending moments, and their buckling behavior, load bearing capacity, stiffness, ductility, and energy absorption capacity were determined. For this purpose, monotonic and cyclic loading experiments were carried out on 30 CFS channel members at 15 different eccentricities. Then, material properties were determined by axial monotonic tensile and very low cycle fatigue tests for use in numerical studies. From the experimental results, the buckling modes, bearing capacities, ductility, stiffness, and energy absorption capacities of the members were obtained. The characteristics of the members were compared according to the stress state of the lips. According to the data obtained from the displacement transducer placed on the lips and on the back of the web, information about the buckling mode and curvature of the members was obtained. Finally, monotonic, and cyclic loading results were compared to determine the differences in the buckling behavior of the members.