• 제목/요약/키워드: arches

검색결과 348건 처리시간 0.026초

연속 응답 스펙트럼 분석에 의한 아치의 동적 직접 및 간접 좌굴 특성 (Dynamic Direct and Indirect Buckling Characteristics of Arch by Running Response Spectrum)

  • 윤태영;김승덕
    • 한국공간정보시스템학회:학술대회논문집
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    • 한국공간정보시스템학회 2004년도 춘계 학술발표회 논문집 제1권1호(통권1호)
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    • pp.161-168
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    • 2004
  • The dynamic instability of snapping phenomena has been studied by many researchers. Few papers deal with dynamic buckling under loads with periodic characteristics, and the behavior under periodic excitations is expected to be different from behavior under STEP excitations. We investigate the fundamental mechanisms of the dynamic instability when the sinusoidally shaped arch structures are subjected to sinusoidally distributed excitations with pin-ends. The mechanisms of dynamic indirect snapping of shallow arches are especially investigated under not only STEP function excitations but also under sinusoidal harmonic excitations, applied in the up-and-down direction. The dynamic nonlinear responses are obtained by the numerical integration of the geometrically nonlinear equation of motion, and examined by Fourier spectral analysis in order to get the frequency-dependent characteristics of the dynamic instability for various load levels.

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쌍생아의 치열궁크기에 관한 유전학적 연구 (A GENETIC SRTUDY ON THE DIMENSION OF DENTAL ARCHES IN TWINS)

  • 김남일;양정강;김만수
    • 대한치과의사협회지
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    • 제9권1호
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    • pp.43-48
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    • 1971
  • The purpose of this study is to evaluate the influence of genetics of the dimensions of dental arches in twins. Thirty-four pairs of Korean twins, of which twenty-three were monozygotic and eleven dizygotic, participated in the study. The twins ranged in age from 6 years to 12 years with mixed dentition. The results were as follows: 1) No significant differences were observed between male and female in mean interpair diffenences of monozygotic twins. 2) Mean interpair differences of monozygotic twins were lesser than these of dizygotic twins. 3) Highly significiant zygotic differences were observed in the mean interpair differences of the width of upper and lower dental arch. This suggest that there is a significant component of hereditary variability.

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순수 휨모멘트를 받는 아치의 횡좌굴에 관한 연구 (A Study on Lateral Torsional Budding of Arch Subjected to Pure Bending Moment)

  • 김생빈;유재흥;이성철
    • 대한토목학회논문집
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    • 제9권3호
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    • pp.13-19
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    • 1989
  • 박판으로 이루어진 아치가 양단에서 휨모멘트를 받을 때 발생하는 횡좌굴에 대한 지배 미분방정식이 제시되었다. 미분방정식은 updated Lagrangian 방법에 따른 증분형태의 가상일의 원리에 의하여 유도 되었다. 본 연구에서 구한 임계모멘트 값들을 다른 결과들과 비교함으로써 본 연구의 타당성을 검토하여 보았다.

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In-plane free vibrations of catenary arches with unsymmetric axes

  • Wilson, James F.;Lee, Byoung Koo
    • Structural Engineering and Mechanics
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    • 제3권5호
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    • pp.511-525
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    • 1995
  • The differential equations governing in-plane free vibrations of the elastic, catenary arch with rotatory inertia are derived in Cartesian coordinates. Frequencies and mode shapes are computed numerically for such arches with unsymmetric axes, for both clamped-clamped and hinged-hinged end constraints. The lowest four natural frequency parameters are reported, with and without rotatory inertia, as a function of three nondimensional system parameters; the span to cord length ratio e, the slenderness ratio s, and the rise to cord length ratio f. Experimental measures of frequencies and mode shapes for several laboratory-scale catenary models serve to validate the theoretical results.

Considerations for the Survival of Complete Arch Implant-Supported Zirconia Restorations; Status of Antagonistic Arches and Stress Distribution on Frameworks: A Case Report

  • Choi, Jung-Yoo;Sim, Jae-Hyuk;Yeo, In-Sung Luke
    • Journal of Korean Dental Science
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    • 제10권2호
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    • pp.74-81
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    • 2017
  • This report describes two cases of complete arch implant-supported restorations. The first patient had seven dental implants in each arch with monolithic zirconia frameworks. At four weeks' follow-up, the one-piece maxillary framework was fractured, which was re-designed and re-fabricated using laser-sintered cobalt-chrome alloy. The second patient had four implants in the mandible only. A mandibular monolithic zirconia framework and a maxillary conventional complete denture were fabricated and delivered. At five years' follow-up, the patient reported no significant discomfort. Careful consideration and monitoring of the status of antagonistic arches and stress distribution on zirconia frameworks were suggested for complete arch implant-supported fixed restorations.

전단변형을 고려한 불연속 단면을 갖는 변화곡률 아치의 자유진동 해석 (Free Vibration Analysis of Stepped Noncircular Arches with Shear Deformation)

  • 오상진;모정만;진태기
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2005년도 추계학술대회논문집
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    • pp.768-771
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    • 2005
  • The purpose of this paper is to investigate the free vibration of stepped noncircular arches. Taking into account the effects of axial deformation, rotatory inertia and shear deformation, the governing differential equations are solved numerically for the elliptic and sinusoidal geometries with hinged-hinged, hinged-clamped, and clamped-clamped end constraints. The lowest four natural frequencies are presented as functions of four non-dimensional system parameters: the arch rise to span length ratio, the slenderness ratio, the section ratio, and the discontinuous sector ratio.

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Cervical chondrocutaneous remnant: a case report

  • Park, Dae Hwan;Lee, June Key;Baik, Bong Soo;Yang, Wan Suk;Kim, Sun Young
    • 대한두개안면성형외과학회지
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    • 제23권5호
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    • pp.241-245
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    • 2022
  • Cervical chondrocutaneous branchial remnants are very rare congenital lesions of the lateral neck; thus, our knowledge of this condition derives almost entirely from occasional case reports in the literature. They are thought to originate from the branchial arches and, therefore, can be found anywhere on the pathway along which those branchial arches migrate during embryogenesis. We report the case of a 5-year-old girl presenting with a cervical chondrocutaneous branchial remnant on the right lateral neck that had existed since birth, with no other anomalies.

EQUATIONS OF MOTION FOR CRACKED BEAMS AND SHALLOW ARCHES

  • Gutman, Semion;Ha, Junhong;Shon, Sudeok
    • Nonlinear Functional Analysis and Applications
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    • 제27권2호
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    • pp.405-432
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    • 2022
  • Cracks in beams and shallow arches are modeled by massless rotational springs. First, we introduce a specially designed linear operator that "absorbs" the boundary conditions at the cracks. Then the equations of motion are derived from the first principles using the Extended Hamilton's Principle, accounting for non-conservative forces. The variational formulation of the equations is stated in terms of the subdifferentials of the bending and axial potential energies. The equations are given in their abstract (weak), as well as in classical forms.