• Title, Summary, Keyword: axisymmetric shell

Search Result 79, Processing Time 0.079 seconds

Free Vibration Analysis of Axisymmetric Cylindrical Shell by Sylvester-Transfer Stiffness Coefficient Method (실베스터-전달강성계수법에 의한 축대칭 원통형 셸의 자유진동 해석)

  • Choi, Myung-Soo;Yeo, Dong-Jun
    • Journal of the Korea Society For Power System Engineering
    • /
    • v.17 no.2
    • /
    • pp.46-55
    • /
    • 2013
  • In this paper, the computational algorithm for free vibration analysis of an axisymmetric cylindrical shell is formulated by the Sylvester-transfer stiffness coefficient method (S-TSCM) which combines the Sylvester's inertia theorem and the transfer stiffness coefficient method. After the computational programs for obtaining the natural frequencies and natural modes of the axisymmetric cylindrical shell are made by the S-TSCM and the finite element method (FEM), the computational results which are natural frequencies, natural modes, and computational times by both methods are compared. From the computational results, we can confirm that S-TSCM has the reliability in the free vibration analysis of the axisymmetric cylindrical shell and is superior to FEM in the viewpoint of computational times.

Non-axisymmetric dynamic response of buried orthotropic cylindrical shells under moving load

  • Singh, V.P.;Dwivedi, J.P.;Upadhyay, P.C.
    • Structural Engineering and Mechanics
    • /
    • v.8 no.1
    • /
    • pp.39-51
    • /
    • 1999
  • The dynamic response of buried pipelines has gained considerable importance because these pipelines perform vital role in conducting energy, water, communication and transportation. After realizing the magnitude of damage, and hence, the human uncomfort and the economical losses, researchers have paid sincere attention to this problem. A number of papers have appeared in the past which discuss the different aspects of the problem. This paper presents a theoretical analysis of non-axisymmetric dynamic response of buried orthotropic cylindrical shell subjected to a moving load along the axis of the shell. The orthotropic shell has been buried in a homogeneous, isotropic and elastic medium of infinite extent. A thick shell theory including the effects of rotary inertia and shear deformation has been used. A perfect bond between the shell and the surrounding medium has been assumed. Results have been obtained for very hard (rocky), medium hard and soft soil surrounding the shell. The effects of shell orthotropy have been brought out by varying the non-dimensional orthotropic parameters over a long range. Under these conditions the shell response is studied in axisymmetric mode as well as in the flexural mode. It is observed that the shell response is significantly affected by change in orthotropic parameters and also due to change of response mode. It is observed that axial deformation is large in axisymmetric mode as compared to that in flexural mode.

Dynamic Characteristics of Reinforced Concrete Axisymmetric Shell with Initial Imperfection -effect of wall imperfection on the dynamic response- (초기결함을 갖는 철근 콘크리트 축대칭 쉘의 동적 특성;벽체 결함의 영향을 중심으로)

  • 조진구
    • Magazine of the Korean Society of Agricultural Engineers
    • /
    • v.42 no.3
    • /
    • pp.114-120
    • /
    • 2000
  • In this study a computer program considering initial imperfection of wall of axisymmetric reinforced concrete shell which show plastic deformation by large external loading is developed. initial imperfection of wall of axisymmetric reinforced concrete shell is assumed as sinusoidal curve expressed as {{{{ {W }_{i } }}}}={{{{ {W}_{0 } }}}}sin (n$\pi$y/$\ell$)y. The developed program is applied to the analysis of the dynamic response of axisymmetric reinforced concrete shell when the wall has initial imperfection. The initial imperfection of 0.0 -5.0, and 5cm and steel ratio 0.3, and 5% are tested for numerical examples. The effects of the wall initial imperfection and steel ratio on the dynamic response of the axisymmetric reinforced concrete shell are analysed, It is shown that the direction of the initial imperfection is very important factors for determining the dynamic response.

  • PDF

Dynamic Response Analysis of Cylindrical Shell with Axisymmetric Loading (축대칭 하중을 받는 원통형 셸의 동적응답 해석)

  • Choi, Myung-Soo;Yeo, Dong-Jun
    • Journal of the Korea Society For Power System Engineering
    • /
    • v.17 no.6
    • /
    • pp.33-39
    • /
    • 2013
  • It is very important to analyze the dynamic responses of the shell structures from the viewpoint of the design of shell structures with a variety of axisymmetric loadings. In this paper, the computational algorithm for the dynamic response analysis of an cylindrical shell with axisymmetric loading is formulated by the transfer mass coefficient method based on the transfer of mass coefficient. After the computational programs for obtaining the dynamic responses of cylindrical shells with axisymmetric loading are made by the transfer mass coefficient method and the finite element method, the computational results by both methods are compared. From the computational results, we can confirm that the transfer mass coefficient method has the effectiveness in the dynamic response analyses of cylindrical shells with a variety of axisymmetric loadings.

Axisymmetric large deflection analysis of fully and partially loaded shallow spherical shells

  • Altekin, Murat;Yukseler, Receb F.
    • Structural Engineering and Mechanics
    • /
    • v.47 no.4
    • /
    • pp.559-573
    • /
    • 2013
  • Geometrically non-linear axisymmetric bending of a shallow spherical shell with a clamped or a simply supported edge under axisymmetric load was investigated numerically. The partial load was introduced by the Heaviside step function, and the solution was obtained by the finite difference and the Newton-Raphson methods. The thickness of the shell was considered to be uniform and the material was assumed to be homogeneous and isotropic. Sensitivity analysis was made for three geometrical parameters. The accuracy of the algorithm was checked by comparing the central deflection, the radial membrane stress at the edge, or the transverse shear force with the solutions of plates and shells in the literature and good agreement was obtained. The main findings of the study can be outlined as follows: (i) If the shell is fully loaded the central deflection of a clamped shell is larger than that of a simply supported shell provided that the shell is not very shallow, (ii) if the shell is partially loaded the central deflection of the shell is sensitive to the parameters of thickness, depth, and partial loading but the influence of the boundary conditions is negligible.

Non-axisymmetric dynamic response of imperfectly bonded buried orthotropic pipelines

  • Dwivedi, J.P.;Mishra, B.K.;Upadhyay, P.C.
    • Structural Engineering and Mechanics
    • /
    • v.6 no.3
    • /
    • pp.291-304
    • /
    • 1998
  • This paper deals with the non-axisymmetric dynamic response of an imperfectly bonded buried orthotropic pipeline subjected to longitudinal wave (P-wave) excitation. An infinite cylindrical shell model, including the rotary inertia and shear deformation effects, has been used for the pipeline. For some cases comparison of axisymmetric and non-axisymmetric responses have also been furnished.

Stress Analysis of Axisymmetric Cylindrical Shell (축대칭 원통형 셸의 응력해석)

  • Choi, M.S.;Yeo, D.J.
    • Journal of the Korea Society For Power System Engineering
    • /
    • v.16 no.6
    • /
    • pp.45-51
    • /
    • 2012
  • In this paper, the algorithm for the static analysis of an axisymmetric cylindrical shell by using the finite element-transfer stiffness coefficient method (FE-TSCM) is suggested. TE-TSCM combining both the modeling procedure of the finite element method (FEM) and the transfer procedure of the transfer stiffness coefficient method (TSCM) has the advantages of FEM and TSCM. After computational programs are made by both FE-TSCM and FEM for the stress analysis of the axisymmetric cylindrical shell, we compare the numerical results by FE-TSCM with those of FEM for two computational models in order to confirm the trust of FE-TSCM.

Two Node Meridional Strain-based Axisymmetric Shell Elements (자오 변형률에 근거한 2절검 축대칭 셸요소)

  • Ryu, Ha-Sang;Sin, Hyo-Chol
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.21 no.6
    • /
    • pp.925-932
    • /
    • 1997
  • Two shear-flexible curved axisymmetric shell elements with two nodes, LCCS(linear curvature and constant strain) and CCCS(constant curvature and constant strain) are designed based on the assumed meridional strain fields and shallow shell geometry. At the element level, meridional curvature, membrane strain and shear strain fields are assumed by using polynomials and the displacement fields are obtained by integrating the assumed strain fields along the shallowly curved meridian. The formulated elements have high order displacement fields consistent with the strain field. Several test problems are given to demonstrate the performance of the two elements. Analysis results obtained reveal that the elements are very accurate in the displacement and the stress predictions.

Vibroacoustics of Axisymmetric Cylindrical Elastic Shells (축대칭 원통 탄성 쉘의 진동음향)

  • Park, Chan-IL
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • /
    • pp.160-165
    • /
    • 2008
  • Fluid loading of a vibrating cylindrical shell can change natural frequencies and vibration magnitudes of the shell and a vibrating cylindrical shell can also change acoustic pressure of fluid. The vibroacoustics of fluid-filled cylindrical shells need the coupled solution of Helmholtz equation and governing equation of a cylindrical shell with boundary conditions. This paper proposed the wall impedance of fluid-filled axisymmetric cylindrical shells, focusing on the inner fluid/shell interaction. To propose the impedance, shell displacements used the linear combination of in vacuo shell modes. Acoustic pressure prediction of fluid used Kirchchoff-Helmholtz Integral equation with Green function of the plane mode. For the demonstration of the proposed results, numerical applications on mufflers were conducted.

  • PDF

Dynamic Characteristics of Reinforced Concrete Axisymmetric Shell with Initial Imperfection (II)-effect of wall imperfection on the dynamic response - (초기결함을 갖는 철근 콘크리트 축대칭 쉘의 동적 특성 (II)-벽체결함의 영향을 중심으로)

  • 조진구
    • Proceedings of the Korean Society of Agricultural Engineers Conference
    • /
    • /
    • pp.200-205
    • /
    • 1999
  • In this study, a computer program considering iniial imperfectiionof axiymmetric reinforced concrete shell which show plastic deformation by large external loading was developed . Initial imperfection of wall was assumed as 'sine curve' which can be expressed as Wi =W0 sin(n$\pi$/1y). The developed model was applied to the analysis of dynamic response of axisymmetric reinforced concrete shell when it has initial imperfection . The initial imperfection of 0.0, -5.0 and 5 cm and steel ration 0 , 3 and 5% were tested for numerical examples.

  • PDF