• 대한토목학회논문집
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• 제36권4호
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• pp.595-604
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• 2016

본 연구에서는 현행 도로교설계기준의 KL-510 하중을 적용하여 장지간 바닥판의 내측 지간에 따른 캔틸레버 바닥판의 설계휨모멘트를 제안하였다. 장지간 바닥판의 내측 지간은 6.0~12.0m 범위를 대상으로 하였고, 캔틸레버 바닥판의 길이는 내측 지간의 30~50%를 적용하였다. 설계휨모멘트의 결정을 위해 바닥판의 직교이방성, 거더의 강성, 그리고 다차로재하계수의 영향을 반영하였으며, 이를 기존의 DB-24 하중에 대한 설계휨모멘트와 비교하였다.

• 대한토목학회논문집
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• 제36권3호
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• pp.375-384
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• 2016

현행, 도로교설계기준에서는 교량바닥판에 대해 지간이 짧은 다거더 플레이트 거더교 위주의 규정을 두고 있으며, 강합성 소수 거더교에 적용되는 장지간 바닥판에 대한 설계규정은 명확하게 없는 실정이다. 이는 소수 거더교의 장지간 바닥판에 적용하기에는 한계가 있으므로 합리적인 설계를 위해서는 관련 규정을 보완할 필요가 있다. 따라서, 본 연구에서는 내측부 교량바닥판의 지간 6.0~12.0m 범위를 대상으로 도로교설계기준의 KL-510 하중을 적용하여 교축방향(종방향)과 교축직각방향(횡방향)에 대한 설계휨모멘트를 제안하였다. 설계휨모멘트는 바닥판의 직교 이방성, 거더의 강성, 그리고 다차로재하계수의 영향이 반영되었으며, 이를 기존의 DB-24 하중에 대한 설계휨모멘트와 비교하였다.

• Steel and Composite Structures
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• 제9권4호
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• pp.303-323
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• 2009

Charts for the bending moments in the closed rib orthotropic deck plate are derived, based on the method originally introduced by Pelikan and Esslinger. New charts are done for EN 1991-2 traffic load distribution schemes. The governing Huber plate equation is solved utilizing Fourier series for various bridge deck plate boundary conditions. Bending moments are given as a function of deck plate rigidities and span length between cross beams. Old diagrams according to DIN 1072, the new ones according to EN 1991-2 and FE analyses results are compared. For typical bridge orthotropic deck plates, it can be concluded that the new EN 1991-2 traffic loads produce larger mid-span bending moments when two lane schemes are used, then those of DIN 1072. For support moments, DIN 1072 gives larger values for any number of lanes, especially under span lengths of 5m. The relevant differences are up to 25%.

• Structural Engineering and Mechanics
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• 제9권5호
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• pp.469-482
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• 2000

A numerical study using nonlinear finite element analysis is performed to investigate the behavior of isolated reinforced concrete walls subjected to combined axial force and in-plane and out-of-plane bending moments. For a nonlinear finite element analysis, a computer program addressing material and geometric nonlinearities was developed. Through numerical studies, the internal force distribution in the cross-section is idealized, and then a new design method, different from the existing methods based on the plane section hypothesis was developed. According to the proposed method, variations in the interaction curve of the in-plane bending moment and axial force depends on the range of the permissible axial force per unit length, that is determined by a given amount of out-of-plane bending moment. As the out-of-plane bending moment increases, the interaction curve shrinks, indicating a decrease in the ultimate strength. The proposed method is then compared with an existing method, using the plane section hypothesis. Compared with the proposed method, the existing method overestimates the ultimate strength for the walls subjected to low out-of-plane bending moments, while it underestimates the ultimate strength for walls subject to high out-of-plane bending moments. The proposed method can address the out-of-plane local behavior of the individual wall segments that may govern the ultimate strength of the entire wall.

• Computers and Concrete
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• 제18권6호
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• pp.1113-1134
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• 2016

A methodology using neural networks has been proposed for rapid prediction of inelastic bending moments in reinforced concrete continuous beams subjected to service load. The closed form expressions obtained from the trained neural networks take into account cracking in concrete at in-span and at near the internal supports and tension stiffening effect. The expressions predict the inelastic moments (considering the concrete cracking) from the elastic moments (neglecting the concrete cracking) at supports. Three separate neural networks are trained since these have been postulated to represent all the beams having any number of spans. The training, validating, and testing data sets for the neural networks are generated using an analytical-numerical procedure of analysis. The proposed expressions are verified for example beams of different number of spans and cross-section properties and the errors are found to be small. The proposed expressions, at minimal input data and computation effort, yield results that are close to FEM results. The expressions can be used in preliminary every day design as they enable a rapid prediction of inelastic moments and require a computational effort that is a fraction of that required for the available methods in literature.

• Earthquakes and Structures
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• 제10권6호
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• pp.1369-1389
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• 2016

The soil-structure interaction effect significantly influences the design of multi-storey buildings subjected to lateral seismic loads. The shear walls are often provided in such buildings to increase the lateral stability to resist seismic loads. In the present work, the nonlinear soil-structure analysis of a G+5 storey RC shear wall building frame having isolated column footings and founded on deformable soil is presented. The nonlinear seismic FE analysis is carried out using ANSYS software for the building with and without shear walls to investigate the effect of inclusion of shear wall on the moments in the footings due to differential settlement of soil mass. The frame is considered to behave in linear elastic manner, whereas, soil mass to behave in nonlinear manner. It is found that the interaction effect causes significant variation in the moments in the footings. The comparison of non-interaction and interaction analyses suggests that the presence of shear wall causes significant decrease in bending moments in most of the footings but the interaction effect causes restoration of the bending moments to a great extent. A comparison is made between linear and nonlinear analyses to draw some important conclusions.

• Structural Engineering and Mechanics
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• 제52권4호
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• pp.767-786
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• 2014

This paper presents the design of reinforced concrete circular footings subjected to axial load and bending in two directions using a new model. The new model considers the soil real pressure acting on contact surface of the circular footings and these are different, with a linear variation in the contact area, these pressures are presented in terms of the axial load, moments around the axis "X" and the axis "Y". The classical model takes into account only the maximum pressure of the soil for design of footings and it is considered uniform at all points of contact area. Also, a comparison is presented in terms of the materials used (steel and concrete) between the two models shown in table, being greater the classical model with respect the new model. Therefore, the new model is the most appropriate, since it is more economic and also is adjusted to real conditions.

• 대한조선학회논문집
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• 제40권5호
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• pp.60-67
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• 2003

For risk or reliability assessment of ship structures against particular hazardous situations such as total loss or sinking due to hull girder collapse, the short-term based response analysis rather than the long-term response analysis is required to determine wave-induced bending moments when the ship encounters a storm of specific duration and with a specified small encounter probability. In the present study, the effects of operational condition and sea states on wave-induced bending moments of large merchant vessels are investigated. A series of the short-term response analyses for a hypothetical VLCC and a Capesize bulk carrier (CSBC) are carried out with varying operational condition and sea states which include ship speed, significant wave height and wave persistence time, using the linear-strip theory based program ABS/SHIPMOTION and the MIT sea-keeping tables. The computed results are also compared with the IACS design formula predictions. The results and insights developed from the present study are summarized.

• 소성∙가공
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• 제10권4호
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• pp.329-337
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• 2001

The finite element simulation model and the program to calculate the reverse moment have been developed to analyse the stress state and deformation of pipe bending using local induction heating with small bending radius in this study. The reverse moment that is to be applied on the bending arm to control the wall thinning ratio of the bending outside to within a particular value. Even though the demand of pipes with small bending radius is increasing in power plants and ship buildings, the welded elbows are still widely used. The bending process with or without a reverse moment acting on the bending arm has been simulated. The reverse moments calculated from the developed program are in good agreement with the finite element simulations and the experiments.

• Computers and Concrete
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• 제27권3호
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• pp.211-223
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• 2021

This paper presents a review of the two widespread approaches which deal with the ultimate strength design of RC slabs subjected to bending moments and torsion: The Field of Moments Method (FoMM) and the Sandwich method (SM). Special attention is paid to the ultimate strain distribution implicitly assumed when using each one of the methodologies, in particular, the yielding of the steel reinforcement. This work analyzes the initial assumption regarding ultimate strain distribution in the SM. Furthermore, this work studies the resisting moments field on which the Wood-Armer method is based, and it finds some inconsistencies. Several examples have been developed.