• Title, Summary, Keyword: open section

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Torsion of circular open cross-section with corrugated inner and outer surface

  • Pala, Yasar;Pala, Abdullah
    • Structural Engineering and Mechanics
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    • v.73 no.1
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    • pp.75-82
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    • 2020
  • In this study, the problem of torsion of bars with open cross section surrounded by corrugated boundaries is analyzed. An approximate analytical solution is given using perturbation technique. First, the stress analysis for circular open cross-section for arbitrary opening angle is formulated and the problem is analytically solved. Second, the open cross-section with corrugated cross section is analyzed using perturbation method. First order contributions to the stresses and the torques have been added. The results have been exemplified and compared by considering special examples.

Multinational Management in Shipping : Flag of Convenience (해운의 다국적 경영 : 편의치적)

  • Kim, Eun-Joo;Pak, Myong-Sop;Han, Nak-Hyun
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.24
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    • pp.51-72
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    • 2004
  • Over the past fifty years, the share of the World's shipping fleet operating under open registry has grown from 4 % to almost half of the total tonnage. While there has been strong opposition based on the costs of maritime disasters and opposition both from the traditional maritime nations, which have suffered erosion of their fleets, and from labour unions, which point to worker exploitation, the shipping companies have found the greater operational and financial flexibility which accompanies open registry to be a considerable attraction The paper consists of seven sections. Section 1 explains the background and of the study. Section 2 reviews the characteristics and definition of FOC. Section 3 is to identify ship register categories and their competitive conditions. Section 4 tackles the emerging forces of globalisation-the advent of FOC. Section 5 deals with legal maritime framework. Section 6 tackles the current structure and characteristics of FOC vessels. Some concluding comments follow in the last section.

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Normal Depth of Best Section (최량수리단면의 등류수심)

  • Yoo, Dong-Hoon
    • Journal of Korea Water Resources Association
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    • v.35 no.6
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    • pp.729-736
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    • 2002
  • The computation of normal depth is one of the most important parts in the design of open channel flow, and the best section is in general the most economic section in the case of constructing artificial open channels. Thus the determination of the normal depth of the best section is the essential item in the design of most open channel flows. To estimate the frictional forces a power law is introduced, which is applicable to most situations in open channel flows. Explicit and consistent forms of equations are deduced for the calculation of normal depth of triangular, rectangular and trapezoidal best sections. Furthermore the equations of normal depth are found to have the same form as those of pipe diameter for the design of pipe flow.

Stability of Cantilevered Laminated Composite Structures with Open Channel Section by Geometrical Shape Variations (채널단면의 기하학적 형상변화에 따른 캔틸레버 적층구조물의 안정성 연구)

  • Park, Won-Tae;Chun, Kyoung-Sik;Son, Byung-Jik
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.8 no.2
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    • pp.169-175
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    • 2004
  • In this paper, the stability of cantilever composite laminated structures with open channel section is studied. This paper deals with the buckling behavior under the variation of the geometrical shape (length ratio, crank angle in the open channel section), the fiber reinforced angle, and so on in order to offer a effective and reliable design data. Also, sensitive analyses are carried out on the stability by the interaction of design factors. Based on this fact, the proper channel section and lamination scheme of composite material cantilever structures are considered in the engineering aspect.

CLINICAL STUDY OF TEMPOROMANDIBULAR JOINT OPEN SURGERY (측두하악관절 관혈적 수술에 관한 임상적 연구)

  • Shim, Cheong-Hwan;Kim, Young-Kyun;Yun, Pil-Young
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.27 no.1
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    • pp.55-65
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    • 2005
  • Most patients with temporomandibular disorder can be treated conservatively. However, open TMJ surgery can be needed in some patients. We analysed the patients with TMD which open surgery has performed since 1998. Open surgery was carried out in 8 patients. Age ranged from 22 to 61 years, with a mean of 42.8years. All patients were male. Final diagnosis was obtained based upon clinical, radiographic and operative finding as follows; habitual luxation, bony ankylosis, traumatic arthritis, disc displacement with destructive change, disc displacement and adhesion. Etiologic factors included trauma(4), infection(2), and unknown(2). Open surgery included arthroplasty with either of condylectomy, eminectomy, meniscoplasty, capsurrohaphy. All patients were recovered uneventfully without severe complications. Some mouth opening limitation and mouth opening deviation remained. Postoperative aggressive physical therapy and careful follow up were performed. In conclusion, open TMJ surgery must be considered in organic disease such as ankylosis, tumor and TMD without favorable recovery after long-term conservative therapy.

Mechanical properties of thin-walled composite beams of generic open and closed sections

  • Rajasekaran, S.
    • Structural Engineering and Mechanics
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    • v.21 no.5
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    • pp.591-620
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    • 2005
  • A general analytical model for thin-walled composite beams with an arbitrary open/(or/and) closed cross section and arbitrary laminate stacking sequence i.e., symmetric, anti-symmetric as well as un-symmetric with respect to the mid plane of the laminate, is developed in the first paper. All the mechanical properties, mechanical centre of gravity and mechanical shear centre of the cross section are defined in the function of the geometry and the material properties of the section. A program "fungen" and "clprop" are developed in Fortran to compute all the mechanical properties and tested for various isotropic sections first and compared with the available results. The locations of mechanical centre of gravity and mechanical shear centre are given with respect to the fibre angle variation in composite beams. Variations of bending and torsional stiffness are shown to vary with respect to the fibre angle orientations.

Dynamic analysis of thin-walled open section beam under moving vehicle by transfer matrix method

  • Xiang, Tianyu;Xu, Tengfei;Yuan, Xinpeng;Zhao, Renda;Tong, Yuqiang
    • Structural Engineering and Mechanics
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    • v.30 no.5
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    • pp.603-617
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    • 2008
  • Three dimensional coupled bending-torsion dynamic vibrations of thin-walled open section beam subjected to moving vehicle are investigated by transfer matrix method. Through adopting the idea of Newmark-${\beta}$ method, the partial differential equations of structural vibration can be transformed to the differential equations. Then, those differential equations are solved by transfer matrix method. An iterative scheme is proposed to deal with the coupled bending-torsion terms in the governing vibration equations. The accuracy of the presented method is verified through two numerical examples. Finally, with different eccentricities of vehicle, the torsional vibration of thin-walled open section beam and vertical and rolling vibration of truck body are investigated. It can be concluded from the numerical results that the torsional vibration of beam and rolling vibration of vehicle increase with the eccentricity of vehicle. Moreover, it can be observed that the torsional vibration of thin-walled open section beam may have a significant nonlinear influence on vertical vibration of truck body.

A Study on the Bending Collapse at the Open Cross-Section Members with Experiment and Analysis (열린 단면 부재의 굽힘 붕괴 실험 및 해석에 관한 연구)

  • 이승철;강신유
    • Journal of the Korean Society for Precision Engineering
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    • v.21 no.4
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    • pp.132-139
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    • 2004
  • The open section members have been used as the members of vehicle such as automotives, airplanes and trains. When vehicles are crashed, these members have absorption of the energy and it is necessary for retainment of the survival space, and as the result, the prediction for the displacement of members in this case of the crash of vehicles is very important. The displacements of members in this case of the crash of automotives show combined aspect of both axial collapse and bending collapse. In the rollover accident when bending collapse happen, the collapse of each members is progressed by the plastic hinge which made from bending moment, and therefore the research for the behavior of members under bending moment after collapse is necessary to determine the internal energy which the members can absorb and the deformed shapes of the members on the step of design. In this paper, the characteristics of bending collapse at the members of the open cross-section were studied with experiment and numerical analysis. We made a comparative studied of the result of the experiment, and changed the axis according to the parallel-axis theorem.

Some generalized weak vector quasivariational-like inequalities for fuzzy mappings

  • Lee Byung-Soo;Cho Hyun-Duk
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.6 no.1
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    • pp.70-76
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    • 2006
  • Some Stampacchia type of generalized weak vector quasivariational-like inequalities for fuzzy mappings was introduced and the existence of solutions to them under non-compact assumption was considered using the particular form of the generalized Ky Fan's section theorem due to Park [15]. As a corollary, Stampacchia type of generalized vector quasivariational-like inequalities for fuzzy mappings was studied under compact assumption using Ky Fan's section theorem [7].

Finite Element Structural Analysis of Open-Section Composite Beams Considering Transverse Shear (전단변형을 고려한 개방형 단면 복합재료 보의 유한요소 구조해석)

  • 정성남
    • Proceedings of the Korean Society For Composite Materials Conference
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    • pp.161-164
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    • 2000
  • In this paper, a finite element structural analysis for thin-walled open-section composite beams with elastic couplings has been performed. The analysis includes the effects of transverse shear across beam sections, torsion warping and constrained warping. Reissner's semi-complementary energy functional is used to obtain the beam st illness coefficients The bending and torsion related warpings and the shear correct ion factors are obtained as part of the analysis. The resulting theory describes the beam kinematics in terms of the axial, flap and lag bending, flap and lag shear, torsion and torsion-warping deformations. The static response has been validated against finite element predict ions, closed form solutions, and experimental data for rectangular sol id and I-beams with elastic couplings. The free vibration results are also compared with available literature.

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