• Title/Summary/Keyword: arches

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Effect of Initial Uniform Moment on Lateral Free Vibration of Arches (등분포 모멘트를 받는 아치의 횡 자유진동)

  • 염응준;한택희;임남형;강영종
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2002.10a
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    • pp.3-10
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    • 2002
  • Recently, arches are used structurally because of their high in-plane stiffness and strength, which result from their ability to transmit most of the applied loading by axial forces actions, so that the bending actions are reduced. On the other hand, the resistances of arches to (out-of-plane,) flexural-torsional behavior depend on the rigidities EI/sub y/, for lateral bending, GJ for Uniform torsion, and EI/sub w/ for warping torsion which are related to axial stress for flexural-torsional behavior. The resistance of an arch to out-of-plane behavior may be reduced by its in-plane curvature, and so it may require significant lateral bracing. Thus. it is supposed that In-plane preloading which cause an axial stress, have an effect on out-of-plane free vibration behavior of arches. Because axial stresses caused increase or decrease out-of-plane stiffness. But study about this substance is insufficient. In this thesis, We will study an effect of preloading on lateral free vibration of arches, using finite element method based on Kang and Yoo's curved beam theory (about curved beam element have 7 degree of freedom including warping) with FORTRAN programming.

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Free Vibrations of Arches with Rectangular Hollow Section having Constant Area (단면적이 일정한 직사각형 중공단면을 갖는 아치의 자유진동)

  • Lee, Tae-Eun;Lee, Byoung-Koo;Park, Kwang-Kyou
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.21 no.4
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    • pp.357-364
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    • 2008
  • This paper deals with the free vibrations of arches with rectangular hollow section having constant area. The differential equations governing free vibrations of arches are derived in polar coordinates, in which the effect of rotatory inertia is included. Natural frequencies is computed numerically for parabolic arches with clamped-clamped, clamped-hinged and hinged-hinged ends. Comparisons of natural frequencies between this study and reference are made to validate theories and numerical methods developed herein. The lowest four natural frequency parameters are reported, with the rotatory inertia, as functions of three non-dimensional system parameters: the breadth ratio, the thickness ratio and the shape ratio

Free vibrations of circular arches with variable cross-section

  • Wilson, James F.;Lee, Byoung Koo;Oh, Sang Jin
    • Structural Engineering and Mechanics
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    • v.2 no.4
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    • pp.345-357
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    • 1994
  • The differential equations governing free, in-plane vibrations of linearly elastic circular arches with variable cross-sections are derived and solve numerically for quadratic arches with three types of rectangular cross sections. Frequencies, mode shapes, cross-sectional load distributions, and the effects of rotatory inertia on frequencies are reported. Experimental measurements of frequencies and their corresponding mode shapes agree closely with those predicted by theory. The numerical methods presented here for computing frequencies and mode shapes are efficient and reliable.

THE STUDIES ON DENTAL ARCH GROWTH IN KOREAN CHILDREN (Arch Circumference) (한국인 아동의 치궁발육에 관한 고찰 (치궁주위경))

  • Sohn, Dong-Soo
    • Journal of the korean academy of Pediatric Dentistry
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    • v.7 no.1
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    • pp.13-16
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    • 1980
  • The purpose of this study is to analyze the changes of arch circumferences during the deciduous dentition period. 600 stone models of maxillary and mandibular arches obtained from the children aged 3,4, or 5 years were under measurement. 1. Arch circumferences increase with age both in males and in females. 2. Arch circumferences of males are longer than females at the age of 4 and 5, but no notable differences at the age of 3. 3. Arch circumferences of upper arches are longer than those of lower arches.

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Free vibration of tapered arches made of axially functionally graded materials

  • Rajasekaran, S.
    • Structural Engineering and Mechanics
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    • v.45 no.4
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    • pp.569-594
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    • 2013
  • The free vibration of axially functionally graded tapered arches including shear deformation and rotatory inertia are studied through solving the governing differential equation of motion. Numerical results are presented for circular, parabolic, catenary, elliptic and sinusoidal arches with hinged-hinged, hinged-clamped and clamped-clamped end restraints. In this study Differential Quadrature element of lowest order (DQEL) or Lagrangian Interpolation technique is applied to solve the problems. Three general taper types for rectangular section are considered. The lowest four natural frequencies are calculated and compared with the published results.

THE VARIATIONAL THEORY OF A CIRCULAR ARCH WITH TORSIONAL SPRINGS AT BOTH EDGES

  • Go, Jae-Gwi
    • Journal of the Korean Mathematical Society
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    • v.44 no.3
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    • pp.707-717
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    • 2007
  • Arches are constrained with rotational resistance at both edges. An energy method is used to derive variational formulation which is used to prove the existence of equilibrium states of elastic circular arches for the torsional spring constants ${\rho}-\;{\geq}\;0,\;{\rho}+\;{\geq}\;0,\;and\;{\rho}-\;+\;{\rho}+\;>\;0$. The boundary conditions are searched using the existence of minimum potential energy.

Free Vibration Analysis of Arches With General Boundary Condition (일반 경계조건 아치의 자유진동해석)

  • 이태은;이종국;이병구
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2001.11b
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    • pp.995-999
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    • 2001
  • This paper deals with the free vibrations of arches with general boundary condition. Based on the dynamic equilibrium equations of a arch element acting the stress resultants and the inertia forces, the governing differential equation is derived for the in-plane free vibration of such arches. Differential equations are solved numerically to calculate natural frequencies. In numerical examples, the parabolic arch is considered. The effects of the arch rise to span length ratio, the slenderness ratio, the vertical spring coefficient and the rotational spring coefficient on the natural frequencies are analyzed.

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Optimum design of parabolic and circular arches with varying cross section

  • Uzman, Umit;Daloglu, Ayse;Saka, M. Polat
    • Structural Engineering and Mechanics
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    • v.8 no.5
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    • pp.465-476
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    • 1999
  • A structural optimization process is presented for arches with varying cross-section. The optimality criteria method is used to develop a recursive relationship for the design variables considering displacement, stresses and minimum depth constraints. The depth at the crown and at the support are taken as design variables first. Then the approach is extended by taking the depth values of each joint as design variable. The curved beam element of constant cross section is used to model the parabolic and circular arches with varying cross section. A number of design examples are presented to demonstrate the application of the method.

Free Vibrations of Hinged-Hinged Arches with Constant Arc Length (일정한 곡선길이를 갖는 양단회전 아치의 자유진동)

  • Lee, Byoung-Koo;Lee, Tae-Eun;Kim, Gwon-Sik;Yoon, Hee-Min
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2008.04a
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    • pp.46-49
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    • 2008
  • This paper deals with the free vibrations of elastica shaped arches with constant arc length. The elastica shaped arches are formed by the post-buckled column whose arc length is always constant. The equations governing free, in-plane vibration of general arch in open literature are modified for applying the free vibrations of elastica shaped arch and solved numerically to obtain frequencies and mode shapes for hinged-hinged end constraints. The effects of rotatory inertia, rise to span length ratio and slenderness ratio on natural frequencies are presented. The frequencies of elastica and parabolic shaped arches are compared. Also, typical mode shapes are presented in figures.

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Free Vibration Analysis of Circular Arches with Rectangular Hollow Section (구형 중공단면을 갖는 원호아치의 자유진동 해석)

  • Lee, Tae-Eun;Lee, Byoung-Koo;Park, Kwang-Kyou;Yoon, Hee-Min
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2008.04a
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    • pp.50-53
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    • 2008
  • The differential equations governing free vibrations of the elastic arches with rectangular hollow section are derived in polar coordinates, in which the effect of rotatory inertia is included. Natural frequencies is computed numerically for circular arches with both clamped ends and both hinged ends. The lowest four natural frequency parameters are reported, with the rotatory inertia, as functions of three non-dimensional system parameters: the breadth ratio, the thickness ratio and the shape ratio.

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