• 제목/요약/키워드: resultants

검색결과 83건 처리시간 0.021초

마제형 대칭 타원 아치의 자유진동: 아치 정점의 합응력 경계조건 이용 재고(再考) (Free Vibrations of Horseshoe Symmetric Elliptic Arch: Using Boundary Conditions of Stress Resultants at Mid-Arc Revisited)

  • 이병구;이태은;김권식;오상진
    • 대한토목학회논문집
    • /
    • 제41권3호
    • /
    • pp.191-200
    • /
    • 2021
  • 이 논문은 아치의 자유진동 해석에서 아치 정점의 합응력 경계조건 이용에 관한 연구이다. 연구 대상 아치는 마제형 타원 대칭 아치이다. 마제형 타원 아치의 자유진동을 다룬 연구는 이미 문헌에 발표된 바 있다. 이 재고 논문은 기존 문헌에서 사용한 아치 양단의 경계조건을 대신할 수 있는 아치 정점의 합응력 경계조건의 적용성을 연구하는 데 그 목적이 있다. 기존 문헌의 이론을 이용하여 아치 정점의 합응력 경계조건을 유도하고, 이를 이용하여 아치의 고유진동수와 진동형을 산정하였다. 이 연구의 결과는 기존 문헌 및 유한요소해 ADINA의 결과와 잘 일치하여, 아치 정점의 합응력 경계조건을 아치의 자유진동 해석에 적용할 수 있음을 검증하였다.

Benchmark Modal Stress-Resultant Distributions for Vibrating Rectangular Plates with Two Opposite Edges Free

  • Y. Xiang;Wang, C.M.;T. Utsunomiya;C. Machimdamrong
    • Computational Structural Engineering : An International Journal
    • /
    • 제1권1호
    • /
    • pp.49-57
    • /
    • 2001
  • This paper presents exact solutions for the modal stress-resultant distributions for vibrating rectangular Mindlin plates involving two opposite sides simply supported while the other two sides free. These exact stress-resultants of vibrating plates with free edges, hitherto unavailable, are very important because they serve as benchmark solutions for checking numerical solutions and methods. Using the exact solutions of a square plate, this paper highlights the problem of determining accurate stress-resultants, especially the transverse shear forces and twisting moments in thin plates, when employing the widely used numerical methods such as the Ritz method and the finite element method. Thus, this study shows that there is a need for researchers to develop refinements to the Ritz method and the finite element method for determining very accurate stress-resultants in vibrating plates with free edges.

  • PDF

다경간 연속보의 자동화 해석 (Automatic Analysis of Continuous Beams with Variable Cross-Section)

  • 신성철;김영일;이태은;이병구
    • 한국농공학회:학술대회논문집
    • /
    • 한국농공학회 2001년도 학술발표회 발표논문집
    • /
    • pp.198-201
    • /
    • 2001
  • This paper deals with the Automatic Analysis of Continuous Beams with Variable Cross-Section. Based on the principle of superpositon and the method of consistent deformations, the governing differential equation is derived for the deflection and stress resultants of such continuous beam. The effects of variable load conditions, the end constraints on the deflection and the stress resultants are analyzed. It is expected that the results obtained herein can be used practically in the structural engineering.

  • PDF

On the theory of curved anisotropic plate

  • Chiang, Yih-Cherng
    • Structural Engineering and Mechanics
    • /
    • 제22권6호
    • /
    • pp.741-759
    • /
    • 2006
  • A general theory which describes the elastic response of a curved anisotropic plate subjected to stretching and bending will be developed by considering the nonlinear effect that reflecting the non-flat geometry of the structure. By applying a newly derived $6{\times}6$ matrix constitutive relation between force resultants, moment resultants, mid-plane strains and deformed curvatures, the governing differential equations for a curved anisotropic plate is developed in the usual manner, namely, by consideration of the constitutive relation and equilibrium equations. Solutions are obtained for simply-supported boundary conditions and compared to corresponding solutions that neglecting the nonlinear effect in the analysis. The comparisons indicate that the nonlinear terms in the equations that caused by the curvature of the structure is crucial for the curved plate analysis. Under certain curved plate geometries the unreasonable results will be induced by neglecting the nonlinear effect in the analysis.

박벽보의 응력해석을 위한 단면상수의 자동산정 (Automatic Determination of Cross Sectional Properties For Stress Analaysis of Thin-walled Beams)

  • 김문영;최명수;장영;김남일
    • 한국강구조학회 논문집
    • /
    • 제14권1호
    • /
    • pp.41-49
    • /
    • 2002
  • 박벽보의 응력해석을 위한 단면상수 값들을 자동적으로 산정하는 알고리즘을 개발한다. 사용자의 편의를 위해서 최소한의 단면정보만으로 복잡한 폐단면 및 개단면에 대하여 단면상수를 자동적으로 산정할 뿐만 아니라 보이론에 의하여 계산된 단면력에 대하여 대응하는 수직응력 또는 전단응력분포의 자동계산이 가능하다. 본 이론 및 프로그램의 타당성을 검증하기 위하여 기존의 논문결과와 비교하여 타당성을 입증한다.

Nondestructive damage evaluation of deep beams

  • Dincal, Selcuk;Stubbs, Norris
    • Structural Monitoring and Maintenance
    • /
    • 제4권3호
    • /
    • pp.269-299
    • /
    • 2017
  • This paper presents a Level III damage evaluation methodology, which simultaneously, identifies the location, the extent, and the severity of stiffness damage in deep beams. Deep beams are structural elements with relatively high aspect (depth-to-length) ratios whose response are no longer based on the simplified Euler-Bernoulli theory. The proposed methodology is developed on the bases of the force-displacement relations of the Timoshenko beam theory and the concept of invariant stress resultants, which states that the net internal force existing at any cross-section of the beam is not affected by the inflicted damage, provided that the external loadings in the undamaged and damaged beams are identical. Irrespective of the aspect ratios, local changes in both the flexural and the shear stiffnesses of beam-type structures may be detected using the approach presented in this paper.

The Poisson effect on the curved beam analysis

  • Chiang, Yih-Cherng
    • Structural Engineering and Mechanics
    • /
    • 제19권6호
    • /
    • pp.707-720
    • /
    • 2005
  • The bending stress formula that taking into account the transverse deformation is developed for plane-curved, untwisted isotropic beams subjected to loadings that result in deformations in the plane of curvature. In order to account the transverse Poisson contraction effect, a new constitutive relation between force resultants, moment resultants, mid-plane strains and deformed curvatures for a curved plate is derived in a $6{\times}6$ matrix form. This constitutive relation will provide the fundamental basis to the analyses of curved structures composing of isotropic or anisotropic materials. Then, the bending stress formula of a curved isotropic beam can be deduced from this newly developed curved plate theory. The stress predictions by the present analysis are compared to those by the analysis that neglected the Poisson contraction effect. The results show that the Poisson effect becomes more significant as the Poisson ratio and the curvature are getting larger.

Analytical solutions of in-plane static problems for non-uniform curved beams including axial and shear deformations

  • Tufekci, Ekrem;Arpaci, Alaeddin
    • Structural Engineering and Mechanics
    • /
    • 제22권2호
    • /
    • pp.131-150
    • /
    • 2006
  • Exact analytical solutions for in-plane static problems of planar curved beams with variable curvatures and variable cross-sections are derived by using the initial value method. The governing equations include the axial extension and shear deformation effects. The fundamental matrix required by the initial value method is obtained analytically. Then, the displacements, slopes and stress resultants are found analytically along the beam axis by using the fundamental matrix. The results are given in analytical forms. In order to show the advantages of the method, some examples are solved and the results are compared with the existing results in the literature. One of the advantages of the proposed method is that the high degree of statically indeterminacy adds no extra difficulty to the solution. For some examples, the deformed shape along the beam axis is determined and plotted and also the slope and stress resultants are given in tables.

Curved laminate analysis

  • Chiang., Yih-Cherng
    • Structural Engineering and Mechanics
    • /
    • 제39권2호
    • /
    • pp.169-186
    • /
    • 2011
  • This paper is devoted to the development of the equations which describe the elastic response of a curved laminate subjected to in-plane loads and bending moments. Similar to the classic $6{\times}6$ ABD matrix constitutive relation of a flat laminate, a new $6{\times}6$ matrix constitutive relation between force resultants, moment resultants, mid-plane strains and deformed curvatures for a curved laminate is formulated. This curved lamination theory will provide the fundamental basis for the analyses of curved laminated structures. The stress predictions by the present curved lamination theory are compared to those by the curved laminate analysis that neglected the nonlinear terms in the derivation of the constitutive relation. The results show that the curved laminate analysis that neglected the nonlinear terms cannot reflect the effect of curvature and can no longer predict the stresses accurately as the curvature becomes noticeable. In this paper, a curved lamination theory that retains the nonlinear terms and, therefore, accounts for the effect of the non-flat geometry of the structure will be developed.