• Title/Summary/Keyword: Statically Determinate Beam

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Plastic collapse behaviour of statically indeterminate beams with a crack under concentrated load (집중하중하의 균열을 갖는 부정정보의 소성붕괴거동)

  • 남기우
    • Journal of Ocean Engineering and Technology
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    • v.10 no.4
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    • pp.67-74
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    • 1996
  • The paper focuse on the effect of a crack subjects to collaspe behabiors of statically indeterminate beams under concentrated load. Through the experiment and calculation, it was revealed that the collaspe load of statically indeterminate beams is much higher than that of statically determinate beams. The cumulative AE event counts of statically determinate beams was less than that of statically indeterminate beams, and the center notch beams sas revealed less than that of the side notch beams.

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Seismic Analysis of Statically Determinate Beams Using Moving Support Finite Elements (동지점 유한요소를 이용한 정정보의 지진해석)

  • Kim, Yong-Woo;Lee, Seoung Yeal;Jhung, Myung Jo
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2013.04a
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    • pp.194-199
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    • 2013
  • Using moving support finite elements, seismic analysis of statically-determinate beams subjected to support motions is performed to show its accuracy and its ease of use. Examples of cantilever and simply-supported beam subjected to support motions are illustrated and the numerical results are compared with the analytical solutions. The examples show the elements facilitate modeling beams with the conventional 2-noded, Hermitian, Euler-Bernoulli beam element. The comparisons of the results with analytical solutions show good agreements with high accuracy.

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Moving Support Elements for Dynamic Finite Element Analysis of Statically Determinate Beams Subjected to Support Motions (지점운동을 받는 정정보의 동해석을 위한 동지점 유한요소 개발)

  • Kim, Yong-Woo;Jhung, Myung Jo
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.37 no.4
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    • pp.555-567
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    • 2013
  • A finite element formulation for a Rayleigh-damped Bernoulli-Euler beam subjected to support motions, which accompanies quasi-static rigid-body motion, is presented by using the quasi-static decomposition method. Moving support beam elements, one of whose nodes is coincident with the moving support, are developed to represent the effect of a moving support. Statically determinate beams subjected to support motions can be modeled successfully by using moving support elements. Examples of cantilever and simply-supported beams subjected to support motions are illustrated, and the numerical results are compared with the analytical solutions. The comparison shows good agreement.

A Study on the Minimum Oil Film Thickness of Crankshaft Main Bearings in Engine (엔진 메인 베어링에서의 최소유막두께에 관한 연구)

  • 최재권;이정현;한동철
    • Tribology and Lubricants
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    • v.8 no.2
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    • pp.50-63
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    • 1992
  • The minimum oil film thicknesses (MOFT) in the crankshaft main bearings of a 1.5 liter, L-4, gasoline engine are measured and calculated to study the dynamically loaded engine bearing. The MOFT are measured simultaneously at each of the five main bearings using the total capacitance method(TCM). To improve the reliability of the TCM, a reasonable determination method of bearing clearance is introduced and the effects of bearipg cavitation and aeration on the test results are analyzed. Also the crankshaft is grounded by means of a slip ring instead of the friction contact method to improve the test precision. The calculation is based on the model of statically determinate beam, short bearing approximation and Mobility method. From the comparison between the measured and calculated MOFT curves, it is found that a qualitative similarity exists between them, but in all cases, measured MOFT are smaller than that of calculated. The crankshaft vibration and the imbalance of the load distribution between the engine bearings have important influence upon the MOFT curve. So it is found that the calculation result from the model of the statically determinate beam has a limitation in predicting bearing performance.

Direct kinematic method for exactly constructing influence lines of forces of statically indeterminate structures

  • Yang, Dixiong;Chen, Guohai;Du, Zongliang
    • Structural Engineering and Mechanics
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    • v.54 no.4
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    • pp.793-807
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    • 2015
  • Constructing the influence lines of forces of statically indeterminate structures is a traditional issue in structural engineering and mechanics. However, the existing kinematic method for establishing these force influence lines is an indirect or mixed approach by combining the force method with the theorem of reciprocal displacements, which is yet inconsistent with the kinematic method for statically determinate structure. This paper proposes the direct kinematic method in conjunction with the load-displacement differential relation for exactly constructing influence lines of reaction and internal forces of indeterminate structures. Firstly, through applying the principle of virtual displacement, the formula for influence lines of reaction and internal forces of indeterminate structure via direct kinematic method is derived based on the released structure. Then, a computational approach with a clear concept and unified procedure as well as wide applicability based on the load-displacement differential relation of beam is suggested to achieve conveniently the closed-form expression of force influence lines, and exactly draw them. Finally, three representative examples for constructing force influence lines of statically indeterminate beams and frame illustrate the superiority of the proposed method.

Numerical Tests of Large Mass Method for Stress Calculation of Euler-Bernoulli Beams Subjected to Support Accelerations (지지점 가속도에 의해 가진되는 보의 응력계산에 대한 거대질량법의 정확도)

  • Kim, Yong-Woo;Choi, Nam Seok;Jhung, Myung Jo
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2013.04a
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    • pp.188-193
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    • 2013
  • The large mass method for dynamic analysis of statically determinate beams subjected to in-phase support motions is justified by showing that the equation of motion of the beams under consideration is equivalent to that of large mass model of the beam when an appropriate large mass ratio is employed. The accuracy of the stress responses based on the beam large mass method is investigated through careful numerical tests. The numerical results are compared to analytic solutions and the comparison shows that the large mass method yields not only the time history of motion but also the distributions of bending moment and shear force accurately.

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Application of the compressive-force path concept in the design of reinforced concrete indeterminate structures: A pilot study

  • Seraj, Salek M.;Kotsovos, Michael D.;Pavlovic, Milija N.
    • Structural Engineering and Mechanics
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    • v.3 no.5
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    • pp.475-495
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    • 1995
  • In the past, physical models have been proposed, in compliance with the concept of the compressive-force path, for the realistic design of various statically determinate structural concrete members. The present work extends these models so as to encompass indeterminate RC structural forms. Pilot tests conducted on continuous beams and fixed-ended portal frames have revealed that designing such members to present-day concepts may lead to brittle types of failure. On the other hand, similar members designed on the basis of the proposed physical models attained very ductile failures. It appears that, unlike current design approaches, the compressive-force path concept is capable of identifying those areas where failure is most likely to be triggered, and ensures better load redistribution, thus improving ductility. The beneficial effect of proper detailing at the point of contraflexure in an indeterminate RC member is to be noted.

An Indeterminate Strut-Tie Model for Prestressed Concrete Beams (프리스트레스트 콘크리트 보의 부정정 스트럿-타이 모델)

  • Chae, Hyun Soo;Yun, Young Mook
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.35 no.4
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    • pp.801-814
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    • 2015
  • In this study, a statically simple indeterminate strut-tie model is proposed for the rational analysis and design of simply supported prestressed concrete beams by reflecting all characteristics of nonlinear structural behavior and load transfer mechanisms. In addition, a load distribution ratio that allows to transform the proposed indeterminate strut-tie model to a determinate model is also suggested to help structural designers conduct the structural analysis and design of simply supported prestressed concrete beams by using the strut-tie model method of current design codes. For verifying of the validity of the proposed model and load distribution ratio, the ultimate strengths of 47 simply supported prestressted concrete beams tested to failure were estimated and the results were compared with those by the strut-tie model methods of current design codes.