• Title/Summary/Keyword: Hermitian Shape Function

Search Result 14, Processing Time 0.024 seconds

The fiber element technique for analysis of concrete-filled steel tubes under cyclic loads

  • Golafshani, A.A.;Aval, S.B.B.;Saadeghvaziri, M.A.
    • Structural Engineering and Mechanics
    • /
    • v.14 no.2
    • /
    • pp.119-133
    • /
    • 2002
  • A beam-column fiber element for the large displacement, nonlinear inelastic analysis of Concrete-Filled Steel Tubes (CFT) is implemented. The method of description is Total Lagrangian formulation. An 8 degree of freedom (DOF) element with three nodes, which has 3 DOF per end node and 2 DOF on the middle node, has been chosen. The quadratic Lagrangian shape functions for axial deformation and the quartic Hermitian shape function for the transverse deformation are used. It is assumed that the perfect bond is maintained between steel shell and concrete core. The constitutive models employed for concrete and steel are based on the results of a recent study and include the confinement and biaxial effects. The model is implemented to analyze several CFT columns under constant and non-proportional fluctuating concentric axial load and cyclic lateral load. Good agreement has been found between experimental results and theoretical analysis.

Extension of Rational Interpolation Functions for FE Analysis of Rotating Beams (회전하는 보의 유한요소해석을 위한 유리형상함수의 확장)

  • Kim, Yong-Woo;Jeong, Jae-Ho
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2009.04a
    • /
    • pp.573-578
    • /
    • 2009
  • Starting from the rotating beam finite element in which the interpolating shape functions satisfies the governing static homogeneous differential equation of Euler-Bernoulli rotating beams, we derived new shape functions that satisfies the governing differential equation which contains the terms of hub radius and setting angle. The shape functions are rational functions which depend on hub radius, setting angle, rotational speed and element position. Numerical results for uniform and tapered cantilever beams with and without hub radius and setting angle are compared with the available results. It is shown that the present element offers an accurate method for solving the free vibration problems of rotating beam.

  • PDF

Extension of Rational Interpolation Functions for FE Analysis of Rotating Beams (회전하는 보의 유한요소해석을 위한 유리형상함수의 확장)

  • Kim, Yong-Woo;Jeong, Jae-Ho
    • Transactions of the Korean Society for Noise and Vibration Engineering
    • /
    • v.19 no.6
    • /
    • pp.591-598
    • /
    • 2009
  • Starting from the rotating beam finite element in which the interpolating shape functions satisfy the governing static homogeneous differential equation of Euler-Bernoulli rotating beams, we derived new shape functions that satisfy the governing differential equation which contains the terms of hub radius and setting angle. The shape functions are rational functions which depend on hub radius, setting angle, rotational speed and element position. Numerical results for uniform and tapered cantilever beams with and without hub radius and setting angle are compared with the available results. It is shown that the present element offers an accurate method for solving the free vibration problems of rotating beams.

Geometric Nonlinear F.E. Analysis of Plane Frames Including Effects of the Internal Hinge (내부(內部)힌지효과(效果)를 고려(考慮)한 평면(平面) 뼈대구조(構造)의 기하학적(幾何學的)인 비선형(非線型) 유한요소해석(有限要素解析))

  • Kim, Moon Young
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.14 no.1
    • /
    • pp.93-103
    • /
    • 1994
  • Two beam/column elements are developed in order to analyze the geometric nonlinear plane irames including the effects of internal hinge and transverse shear deformation. In the case of the first element (finite segment method), tangent stiffness matrix is derived by directly integrating the equilibrium equations whereas in the case of the second element (finite element method) elastic and goemetric stiffness matrices are calculated by using the hermitian polynomials including the effects of internal hinge and shear deformation as the shape function. Numerical results are presented for the selected test problems which demonstrate that both elements represent reliable and highly accurate tools.

  • PDF

Geometric Non-linear Analysis of the Plane Frame Structures including Shear Deformation Effect (전단변형(剪斷變形)을 고려(考慮)한 평면(平面)뼈대 구조물(構造物)의 기하적(幾何的)인 비선형(非線形) 해석(解析))

  • Kim, Moon Young;Chang, Sung Pil
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.10 no.1
    • /
    • pp.27-36
    • /
    • 1990
  • Two beam/column elements in order to analyze the geometric nonlinear plane framed structures including the effects of transverse shear deformation and bending stretching coupling are developed. In the case of the first element (finite segment method), tangent stiffness matrix are derived by directly integrating the equilibrium equations whereas in the case of the second element (finite element method) elastic and geometric stiffness matrices are calculated by using the hermitian polynomials including shear deformation effect as the shape function. Both elements possess the usual six degree of freedoms. Numerical results are presented for the selected test problems which demonstrate that both elements represent reliable and highly accurate tools.

  • PDF

Nonlinear Analysis of IPS System using the multi-noded cable element (다절점 케이블요소를 이용한 IPS 시스템의 비선형 해석)

  • Lee Jun-Seok;Kim Moon-Young;Han Man-Yop;Kim Sung-Bo;Kim Nak-Kyung
    • Proceedings of the Computational Structural Engineering Institute Conference
    • /
    • 2006.04a
    • /
    • pp.623-630
    • /
    • 2006
  • In this paper, a geometric nonlinear analysis procedure of beam-column element including multi-noded cable element is presented. For this, first a stiffness matrix about beam-column element which considers the second effect of initial force supposing the curved shape at each time step with Hermitian polynomials as the shape function is derived and second, tangent stiffness matrix about multi-noded cable element being too. To verify geometric nonlinearity of this newly developed multi-noded cable-truss element, IPS(Innovative Prestressed Support) system using this theory is analysed by geometric nonlinear method and the results are compared with those by linear analysis.

  • PDF

Geometrically Non linear Analysis of Space Frames Including Shear Deformation Effects (전단변형(剪斷變形)을 고려(考慮)한 공간(空間) 뼈대구조(構造)의 기하학적(幾何學的)인 비선형(非線形) 해석(解析))

  • Kim, Moon Young
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.13 no.4
    • /
    • pp.39-49
    • /
    • 1993
  • In order to present the geometrically nonlinear F.E. formulation of space frames, two beam/column elements including the effects of transverse shear deformation and bending stretching coupling are developed. In the case of the first element (Finite segment method), the tangent stiffness matrices are derived by directly integrating the equilibrium equations, whereas in the case of the second element (Finite element method) elastic and geometric stiffness matrices are calculated by using the hermitian polynomials including shear deformation effect as the shape function. Both elements possess the usual twelve degrees of freedom. Also, the bowing function including shear deformation effects is obtained in order to account for the effect of shortening of member chord length due to the bending and torsional behavior. Numerical results are presented for the selected test problems which demonstrate that both elements represent reliable and highly accurate tools.

  • PDF

Spatial Free Vibration and Stability Analysis of Thin-Walled Arches with Variable Curvature (곡률이 변하는 박벽 아치의 3차원 자유진동 및 좌굴해석)

  • 서광진;민병철;김문영
    • Proceedings of the Computational Structural Engineering Institute Conference
    • /
    • 1999.04a
    • /
    • pp.169-176
    • /
    • 1999
  • An improved formulation for spatial stability md free vibration of thin-walled curved beams with variable curvature and non-symmetric cross sections are presented based on the displacement field considering the second order terms of finite semitangential rotations. By introducing Vlasov's assumptions, the total potential energy is derived from the principle of linearized virtual work for a continuum. In this formulation, all displacement parameters and the warping function are defined at the centroid axis so that the coupled terms of bending and torsion are added to the elastic strain energy. Also, the potential energy due to initial stress resultants is consistently derived corresponding to the semitangential rotation and moment. The cubic Hermitian polynomials are utilized as shape functions for development of the curved thin-walled beam element having eight degrees of freedom. In order to illustrate the accuracy and practical usefulness of this study, . numerical solutions for free vibration of arches are presented and compared with resells of other researchers and solutions analyzed by the ABAQUS's shell element.

  • PDF

The Stability Analysis of Non-Conservative System including Damping Effects (감쇠효과(減衰效果)를 고려한 비보존력계(非保存力系) 안정성(安定性) 해석(解析))

  • Kim, Moon Young;Chang, Sung Pil
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.10 no.3
    • /
    • pp.57-65
    • /
    • 1990
  • The finite element menthod for the investigation of the static and dynamic stability of the plane framed structures subjected to non-conservative forces is presented. By using the Hermitian polynomial as the shape function, the geometric stiffness matrix, the load correction stiffness matrix for non-conservative forces, and the matrix equation of internal and external damping are derived. Then, a matrix equation of the motion for the non-conservative system is formulated and the critical divergence and flutter loads are determined from this equation.

  • PDF

Derivation of Exact Dynamic Stiffness Matrix for Non-Symmetric Thin-walled Straight Beams (비대칭 박벽보에 대한 엄밀한 동적 강도행렬의 유도)

  • 김문영;윤희택
    • Proceedings of the Computational Structural Engineering Institute Conference
    • /
    • 2000.10a
    • /
    • pp.369-376
    • /
    • 2000
  • For the general loading condition and boundary condition, it is very difficult to obtain closed-form solutions for buckling loads and natural frequencies of thin-walled structures because its behaviour is very complex due to the coupling effect of bending and torsional behaviour. Consequently most of previous finite element formulations introduced approximate displacement fields using shape functions as Hermitian polynomials, isoparametric interpoation function, and so on. The purpose of this study is to calculate the exact displacement field of a thin-walled straight beam element with the non-symmetric cross section and present a consistent derivation of the exact dynamic stiffness matrix. An exact dynamic element stiffness matrix is established from Vlasov's coupled differential equations for a uniform beam element of non-symmetric thin-walled cross section. This numerical technique is accomplished via a generalized linear eigenvalue problem by introducing 14 displacement parameters and a system of linear algebraic equations with complex matrices. The natural frequencies are evaluated for the non-symmetric thin-walled straight beam structure, and the results are compared with available solutions in order to verify validity and accuracy of the proposed procedures.

  • PDF