• 대한토목학회논문집
• /
• 제31권3A호
• /
• pp.181-187
• /
• 2011

이 연구는 양단이 탄성받침으로 지지된 Timoshenko 보의 자유진동에 관한 연구이다. 회전관성과 전단변형을 동시에 고려하는 Timoshenko 보 이론을 적용하여 탄성받침 보의 자유진동을 지배하는 상미분방정식과 자유단의 경계조건을 유도하였다. 이 상미분방정식을 수치해석하여 고유진동수와 진동형상을 산출하였다. 회전관성과 전단변형이 자유진동에 미치는 영향을 분석하고, 변수연구를 통하여 세장비, 지반계수, 탄성받침 길이 등이 자유진동에 미치는 영향을 그림에 나타내었다. 변위 및 휨 모멘트, 전단력의 진동형상을 그림에 나타내어 최대진폭 및 무변위의 위치를 알 수 있도록 하였다.

• Steel and Composite Structures
• /
• 제50권3호
• /
• pp.265-280
• /
• 2024

The collapse behavior observed in single-story beam-column assembly (SSBCA) do not accurately represent the actual overall stress characteristic of multi-story frame structure (MSFS) under column loss scenario owing to ignoring the interaction action among different stories, leading to a disconnection between the anti-collapse behaviors of "components" and "overall structures", that is, the anti-collapse performance of frame structures with two different structural scales has not yet formed a combined force. This paper conducts a numerical and theoretical study to explore the difference of the collapse behaviors of the SSBCA and MSFS, and further to reveal the internal force relationships and boundary constraints at beam ends of models SSBCA and MSFS. Based on the previous experimental tests, the corresponding refined numerical simulation models were established and verified, and comparative analysis on the resistant-collapse performance was carried out, based on the validated modeling methods with considering the actual boundary constraints, and the results illustrates that the collapse behaviors of the SSBCA and MSFS is not a simple multiple relationship. Through numerical simulation and theoretical analysis, the development laws of internal force in each story beam under different boundary constraints was clarified, and the coupling relationship between the bending moment at the most unfavorable section and axial force in the composite beam of different stories of multi story frames with weld cover-plated flange connections was obtained. In addition, considering the effect of the yield performance of adjacent columns on the anti-collapse bearing capacities of the SSBCA and MSFS during the large deformation stages, the calculation formula for the equivalent axial stiffness at the beam ends of each story were provided.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2007년도 추계학술대회논문집
• /
• pp.471-475
• /
• 2007

Design equations of coupling plates, which connects floor beam of the upper modular unit and overhead beam of the lower one in order to improve serviceability in vibration, are proposed. End conditions of the coupled beams is semi-rigid and the optimal location of the coupling plates are assumed. Rotational constraints for both ends of the coupling plate modeled with beam elements are released and flexibility method is applied to obtain deflection equations of the coupled beam. Proposed equations are defined using the flexibility of the coupling plate, of which size can be determined inversely. Based on numerical analysis, coefficients of the design equations are calibrated and the revised equations are verified to be useful in the design of the coupled beam.

• Computers and Concrete
• /
• 제19권6호
• /
• pp.701-710
• /
• 2017

In this study, the thermoelastic beam in modified couple stress theory due to laser source and heat flux is investigated. The beam are heated by a non-Guassian laser pulse and heat flux. The Euler Bernoulli beam theory and the Laplace transform technique are applied to solve the basic equations for coupled thermoelasticity. The simply-supported and isothermal boundary conditions are assumed for both ends of the beam. A general algorithm of the inverse Laplace transform is developed. The analytical results have been numerically analyzed with the help of MATLAB software. The numerically computed results for lateral deflection, thermal moment and axial stress due to laser source and heat flux have been presented graphically. Some comparisons have been shown in figures to estimate the effects of couple stress on the physical quantities. A particular case of interest is also derived. The study of laser-pulse find many applications in the field of biomedical, imaging processing, material processing and medicine with regard to diagnostics and therapy.

• 한국생산제조학회지
• /
• 제6권4호
• /
• pp.118-123
• /
• 1997

The study suggests a method to analyze the vibration of the multi-stepped beam having the different circular cross-sections. The rotatory inertia, the shear deformation and the torque applied at both ends of the beam are considered in the governing equation. The complex displacement and the variable separation are introduced to derive the solution of the equation of each uniform beam element having constant cross-section. Then boundary conditions are applied to solve the total system. This method uses the mathematically exact solutions unlike numerical method such as the finite element method in solving the problem having the simultaneous differential equations of Timoshenko beam theory. the natural frequencies and the corresponding mode shapes are precise, especially the mode shapes are continuous.

• 교육녹색환경연구
• /
• 제10권2호
• /
• pp.1-7
• /
• 2011

An experimental study to evaluate structural capacity of an embedded plate connected with prestressed concrete beam was performed. Embedded steel plates and prestressed concrete beam were connected with stud-bolts at the ends of concrete beam specimens. About 1,000 kN concentrated load was applied at 450mm away from the end of beam specimen. A 3,000 kN capacity static Oil-jack was used to direct concentrated load. The maximum strain of stud-bolt recorded $90{\times}10^{-6}$(mm/mm) and wide width cracks were not founded. Any falling failures of concrete and large deformations were not founded either between steel plate and prestressed concrete specimen. As a result, construction performance can be improved using this embedded steel plate connection system apply to large space educational facilities.

• 한국자동차공학회논문집
• /
• 제24권4호
• /
• pp.379-385
• /
• 2016

Door impact beam plays a key role in minimizing the occupant injury within the side impacted vehicle through preventing intrusion of the impacting vehicle. Steel pipe type door impact beam has been widely adopted since it has simple structure and the overall strength is easily determined according to the pipe size. The brackets welded at pipe ends connect the door impact beam and the door panels by spot welds. In this study, first, the effect of pipe thickness, bracket thickness and door mounting stiffness was respectively analyzed. Next, application of the tailor rolled pipe was examined and several alterations of the bracket mounting method were considered. Application of tailor rolled pipes with superior bracket mounting method showed remarkable strength enhancement and weight reduction possibility in comparison with the current door impact beam.

• 한국전산구조공학회:학술대회논문집
• /
• 한국전산구조공학회 2000년도 가을 학술발표회논문집
• /
• pp.201-208
• /
• 2000

This paper explores the non-linear behavior of tapered beam subjected to a floating concentrated load. For applying the Bernoulli-Euler beam theory to this beam, the bending moment at any point of elastica is obtained from the final equilibrium state. By using the bending moment equation and the Bernoulli-Euler beam theory, the differential equations governing the elastica of clamped-roller beam are derived, and solved numerically. Three kinds of tapered beam types are considered. The numerical results of the non-linear behavior obtained in this study are agreed quite well to the results obtained from the laboratory-scale experiments.

• Steel and Composite Structures
• /
• 제19권3호
• /
• pp.635-659
• /
• 2015

In this study, natural frequency analysis of a large deflected cantilever laminated composite beam fixed at both ends, which forms the case of a pre-stressed curved beam, is investigated. The laminated beam is considered to have symmetric and asymmetric lay-ups and the effective flexural modulus of the beam is used in the analysis. In order to obtain the pre-stressed composite curved beam case, an external vertical concentrated load is applied at the free end of a cantilever laminated composite beam and then the loading point of the deflected beam is fixed. The non-linear deflection curve of the flexible beam undergoing large deflection is obtained by the Reversion Method. The curved laminated composite beam is modeled by using the Finite Element Method with a straight-beam element approach. The effects of orientation angle and vertical load on the natural frequency parameter for the first four modes are examined and the results obtained are given in graphics. It has been found that the effect of the load parameter, which forms the curved laminated beam, on the natural frequency parameter, almost disappears after a certain value of the load parameter. This certain value differs for each laminated curved beam and each vibration mode.

• 콘크리트학회논문집
• /
• 제13권6호
• /
• pp.602-609
• /
• 2001

중앙부 철골조와 단부 RC조로 이루어진 혼합구조보인 RS보의 전단강도를 예측하기 위한 해석모델로서 Strut-and-Tie Model을 개발하였다. 또한 제안된 모델은 강재매입구간에서의 RC부위에 발생한 전단균열에 의한 콘크리트의 강도저하를 고려하기 위하여, 콘크리트의 연화효과를 고려할 수 있는 모델로 제안되었다. 제안모델은 전단균열이 발생된 혼합구조 보에서 평형방정식, 적합방정식, 구성방정식을 이용하여 전단강도를 구할 수 있으며, 이에 따라 구성재료의 파괴를 예측할 수 있다. 따라서 기존의 식에서 예측하지 못한 콘크리트의 파괴에 의한 전단강도를 예측할 수 있음을 확인하였다. 해석결과 예측전단강도대비 실험강도의 비가 평균 1.02, 표준편차 0.126의 매우 만족스러운 결과를 보였다.