• Steel and Composite Structures
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• 제25권3호
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• pp.287-298
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• 2017

The present study aims to determine the structural response of full scaled rectangular columns under both of vertical and lateral loads using numerical methods. In the study, the composite columns considering full concrete filled circular steel tube (FCFRST) and concrete filled double-skin rectangular steel tube (CFDSRST) section types are numerically modelled using ANSYS software. Vertical and lateral loads are applied to models to assess the structural response of the composite elements. Also similar investigations are done for reinforced concrete rectangular (RCR) columns to compare the results with those of composite elements. The analyses of the systems are statically performed for both linear and nonlinear materials. In linear static analyses, both of vertical and lateral loads are applied to models as only one step. However in nonlinear analyses, while vertical loads are applied to model as only one step, lateral loads are applied to systems as step by step. The displacement and stress changes in some critical nodes and sections and contour diagrams are reported by graphs and figures. At the end of the study, it is demonstrated that the nonlinear models reveal more accurate result then those of linear models. Also, it is highlighted that composite columns provide more and more safety, ductility compared to reinforced concrete column.

• 대한기계학회논문집
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• 제10권6호
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• pp.870-875
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• 1986

본 연구에서는 랙의 이끝부분을 full-rounded tip으로 설계한 후, 이에 의하 여 창성되는 피니언의 이뿌리곡선을 구하여 전체치형을 완성하였다. 그리고 합성치 형기어의 미끄름율, 유효이뿌리원에서의 공칭굽힘응력과 두쌍접촉호의 길이대 원호부 분접촉호의 길이의 비인 접촉계수를 해석적인 방법으로 구하였다.또한 이들 특성들 과 물림율등 제특성을 비교.검토하여 공구압력각, 인벌류우트부분의 크기를 나타내는 물림각 및 원호반경등의 변화에 대한 제특성의 변화를 고려한 합성치형의 성능을 향상 시킬 수 있는 설계방법을 구하였으며, 합성치형과 표준인버류우트치형을 비교하였다.

• Steel and Composite Structures
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• 제51권5호
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• pp.563-573
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• 2024

This research experimentally evaluated the local stress distribution along the cross-section of composite beams under both positive and negative moments. The experiment utilized a large-scale, two-story, two-by-three bay steel gravity frame with a concrete on metal deck floor system. The composite shear connections, which are nominally assumed to be pinned under gravity loading, can develop non-negligible moment-resisting capacity when subjected to lateral loads. This paper discusses the local stress distribution, orshear lag effects, observed near the beam-to-column connections when subjected to combined gravity and lateral loading. Strain gauges were used for measurements along the beam depth at varying distances from the connection. The experimental data showed amplified shear lag effects near the unconnected region of the beam web and bottom flange under the applied loading conditions. These results indicate that strain does not vary linearly across the beam cross-section adjacent to the connection components. This insight has implications for the use of experimental strain gauge data in estimating beam demands near the connections. These findings can be beneficial in informing instrumentation plans for future experimental studies on composite beams.

• Steel and Composite Structures
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• 제25권3호
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• pp.337-346
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• 2017

Sandwich shells made of composite materials are the main focus on recent literature parallel to the requirements of industry. They are commonly chosen for the modern engineering applications which require moderate strength to weight ratio without dependence on conventional manufacturing techniques. The investigations on hyperbolic paraboloidal formed sandwich composite shells are limited in the literature contrary to shells that have a number of studies, consisting of doubly curved surfaces, arbitrary boundaries and laminations. Because of the lack of contributive data in the literature, the aim of this study is to present the effects of curvature on hyperbolic paraboloidal formed, layered sandwich composite surfaces that have arbitrary boundary conditions. Analytical solution methodology for the analyses of stresses and deformations is based on Third Order Shear Deformation Theory (TSDT). Double Fourier series, which are specialized for boundary discontinuity, are used to solve highly coupled linear partial differential equations. Numerical solutions showing the effects of shell geometry are presented to provide benchmark results.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2005년도 춘계학술발표대회 논문집
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• pp.94-97
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• 2005

The strength of aluminum 7075 and carbon composite hybrid joints was studied for adhesive, bolt, and the adhesive-bolt combined joints. Several hybrid joint specimens were tested to get the failure load and modes for three types of the joints. Adhesive Cytec EA9394S was used for aluminum and carbon bonding. Failure load of the adhesive-bolt combined joint was 94 % of the sum of the failure load of the separately bonded and bolted joints. Hybrid joint also showed more stable failure behavior than the simple adhesive or bolted joint.

• Steel and Composite Structures
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• 제11권2호
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• pp.169-181
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• 2011

The behavior of connections between open sandwich slabs and double steel skin composite walls in steel plate-concrete(SC) structure is investigated by a series of experimental programs to identify the roles of components in the transfer of forces. Such connections are supposed to transfer shear by the action of friction on the interface between the steel surface and the concrete surface, as well as the shear resistance of the bottom steel plate attached to the wall. Experimental observation showed that shear transfer in slabs subjected to shear in short spans is explained by direct force transfer via diagonal struts and indirect force transfer via truss actions. Shear resistance at the interface is enhanced by the shear capacity of the shear plate as well as friction caused by the compressive force along the wall plate. Shear friction resistance along the wall plate was deduced from experimental observation. Finally, the appropriate design strength of the connection is proposed for a practical design purpose.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2002년도 추계학술발표대회 논문집
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• pp.241-244
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• 2002

Recently, the size of glass panel is increased to $1250 mm{\times}1100 mm{\times}0.7 mm$, whose mass is 2.65 kg, which requires much stiffer robot structure. In addition to the high stiffness, the robot hands and wrists for glass panel handling should have miller surface finishing of its outer surface to prevent particles and dusts from adhering on the surface. The maximum height of the robot structure should not be larger than 1500 mm because other automated guided vehicles (AGV) and transfer equipments have been designed within this size limit. The difference of maximum deflections of the four ends of the hands before and after loading the glass panel should be less than 2.0 mm. In this work, the robot hands and wrists for handling large glass panel displays were designed based on the axiomatic design using the finite element method along with optimization routine.

• 대한기계학회논문집A
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• 제25권11호
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• pp.1802-1812
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• 2001

The theoretical method is developed to investigate the effects of ring stiffeners on free vibration characteristics and transient response for the ring stiffened composite cylindrical shells subjected to the impulse pressure Loading. In the theoretical procedure, the Love's thin shell theory combined with the discrete stiffener theory to consider the ring stiffening effect is adopted to formulate the theoretical model. The concentric or eccentric ring stiffeners are laminated with composite and have the uniform rectangular cross section. The modal analysis technique is used to develop the analytical solutions of the transient problem. The analysis is based on an expansion of the loads, displacements in the double Fourier series that satisfy the boundary conditions. The effect of stiffener's eccentricity, number, size, and position on transient response of the shells is examined. The results are verified by comparison with FEM results.

• 한국음향학회:학술대회논문집
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• 한국음향학회 1999년도 학술발표대회 논문집 제18권 1호
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• pp.307-310
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• 1999

An analysis of the free vibration for the metal-piezoceramic composite thin plates is described. The purpose of this study is to develop a equivalent method for the free vibration analysis of metal-piezoceramic composite thin plates which are not symmetrically about the adhered layer and the piezoelectric effect. In order to confirm the validity of the vibration analysis, double Fourier sine series is used as a modal displacement function of a metal-piezoceramic composite thin plate and applied to the free vibration analysis of the plate under various boundary conditions.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 봄 학술발표회 논문집
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• pp.427-432
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• 2003

An analytical method to predict the flexural behavior of composite girder is presented in which the early-age properties of concrete are specified including maturing of elastic modulus, creep and shrinkage. The time dependent constitutive relation accounting for the early-age concrete properties is derived in an incremental format by expanding the total form of stress-strain relation by the first order Taylor series with respect to the reference time. The sectional analysis calculates the axial and curvature strains based on the force and moment equilibriums. The deflection curve of the box girder approximated by the quadratic polynomial function is calculated by applying to the proper boundary conditions in the consecutive segments. Numerical applications are made for the 3-span double composite steel box girders which is a composite bridge girder filled with concrete at the bottom of the steel box in the negative moment region. The one dimensional finite element analysis results are compared with those of the three dimensional finite element analysis and the analytical method based on the sectional analysis. Close agreement is observed among the three methods.