The Experts below are selected from a list of 78 Experts worldwide ranked by ideXlab platform
Song Cen - One of the best experts on this subject based on the ideXlab platform.
-
a shape free 8 node Plane Element unsymmetric analytical trial function method
International Journal for Numerical Methods in Engineering, 2012Co-Authors: Song Cen, Guohua ZhouAbstract:SUMMARY The unsymmetric FEM is one of the effective techniques for developing finite Element models immune to various mesh distortions. However, because of the inherent limitation of the metric shape functions, the resulting Element models exhibit rotational frame dependence and interpolation failure under certain conditions. In this paper, by introducing the analytical trial function method used in the hybrid stress-function Element method, an effort was made to naturally eliminate these defects and improve accuracy. The key point of the new strategy is that the monomial terms (the trial functions) in the assumed metric displacement fields are replaced by the fundamental analytical solutions of Plane problems. Furthermore, some rational conditions are imposed on the trial functions so that the assumed displacement fields possess fourth-order completeness in Cartesian coordinates. The resulting Element model, denoted by US-ATFQ8, can still work well when interpolation failure modes for original unsymmetric Element occur, and provide the invariance for the coordinate rotation. Numerical results show that the exact solutions for constant strain/stress, pure bending and linear bending problems can be obtained by the new Element US-ATFQ8 using arbitrary severely distorted meshes, and produce more accurate results for other more complicated problems. Copyright © 2012 John Wiley & Sons, Ltd.
-
A 4-node hybrid stress-function (HS-F) Plane Element with drilling degrees of freedom less sensitive to severe mesh distortions
Computers & Structures, 2011Co-Authors: Song Cen, Mingjue ZhouAbstract:A simple but robust 4-node hybrid stress-function (HS-F) membrane Element with drilling degrees of freedom is developed based on the principle of minimum complementary energy. Its stress fields are derived from the first seven fundamental analytical solutions of the Airy stress function. The assumed displacements along Element boundaries employ compatible mode of Allman for which the nodal drilling degrees of freedom are considered. Numerical results show that the proposed new Element, denoted as HSF-Q4@q-7@b, exhibits much improved numerical accuracy and robust performance. In particular, the Element performs well even when the Element shape degenerates into a triangle or concave quadrangle.
-
analytical trial function method for development of new 8 node Plane Element based on the variational principle containing airy stress function
Engineering Computations, 2010Co-Authors: Song Cen, Xiaoming ChenAbstract:Purpose − The purpose of this paper is to propose a novel and simple strategy for construction of hybrid‐“stress function” Plane Element. Design/methodology/approach − First, a complementary energy functional, in which the Airy stress function is taken as the functional variable, is established within an Element for analysis of Plane problems. Second, 15 basic analytical solutions (in global Cartesian coordinates) of the stress function are taken as the trial functions for an 8‐node Element, and meanwhile, 15 unknown constants are then introduced. Third, according to the principle of minimum complementary energy, the unknown constants can be expressed in terms of the displacements along Element edges, which are interpolated by Element nodal displacements. Finally, the whole system can be rewritten in terms of Element nodal displacement vector. Findings − A new hybrid Element stiffness matrix is obtained. The resulting 8‐node Plane Element, denoted as analytical trial function (ATF‐Q8), possesses excellent...
Y K Cheung - One of the best experts on this subject based on the ideXlab platform.
-
a refined non linear non conforming triangular plate shell Element
International Journal for Numerical Methods in Engineering, 2003Co-Authors: Y. X. Zhang, Y K CheungAbstract:A refined non-conforming triangular plate/shell Element for geometric non-linear analysis of plates/shells using the total Lagrangian/updated Lagrangian approach is constructed in this paper based on the refined non-conforming Element method for geometric non-linear analysis. The Allman's triangular Plane Element with vertex degrees of freedom and the refined triangular plate-bending Element RT9 are used to construct the present Element. Numerical examples demonstrate that the accuracy of the new Element is quite high in the geometric non-linear analysis of plates/shells. Copyright © 2003 John Wiley & Sons, Ltd.
-
an efficient quadrilateral Plane Element with drilling degrees of freedom using orthogonal stress modes
Computers & Structures, 1992Co-Authors: K Y Sze, Wanji Chen, Y K CheungAbstract:Abstract In this paper, a mixed quadrilateral Plane Element with drilling degrees of freedom using Allman's interpolation scheme is developed. The assumed stress space includes three constant stress modes and four quasi-linear stress modes which are equilibrating for regular Element geometry. Owing to the intrinsic orthogonality of the constant and higher order stress modes, the Element is particularly efficient. Only a 4 × 4 symmetry matrix is required to be inverted while no incompatible displacement modes are involved. The Element has two spurious kinematic modes which, however, can effectively be suppressed by using two very simple stabilization matrices. A number of popular benchmark problems are examined and the accuracy achieved is very satisfactory.
Guohua Zhou - One of the best experts on this subject based on the ideXlab platform.
-
a shape free 8 node Plane Element unsymmetric analytical trial function method
International Journal for Numerical Methods in Engineering, 2012Co-Authors: Song Cen, Guohua ZhouAbstract:SUMMARY The unsymmetric FEM is one of the effective techniques for developing finite Element models immune to various mesh distortions. However, because of the inherent limitation of the metric shape functions, the resulting Element models exhibit rotational frame dependence and interpolation failure under certain conditions. In this paper, by introducing the analytical trial function method used in the hybrid stress-function Element method, an effort was made to naturally eliminate these defects and improve accuracy. The key point of the new strategy is that the monomial terms (the trial functions) in the assumed metric displacement fields are replaced by the fundamental analytical solutions of Plane problems. Furthermore, some rational conditions are imposed on the trial functions so that the assumed displacement fields possess fourth-order completeness in Cartesian coordinates. The resulting Element model, denoted by US-ATFQ8, can still work well when interpolation failure modes for original unsymmetric Element occur, and provide the invariance for the coordinate rotation. Numerical results show that the exact solutions for constant strain/stress, pure bending and linear bending problems can be obtained by the new Element US-ATFQ8 using arbitrary severely distorted meshes, and produce more accurate results for other more complicated problems. Copyright © 2012 John Wiley & Sons, Ltd.
Y. X. Zhang - One of the best experts on this subject based on the ideXlab platform.
-
geometrically nonlinear analysis of laminated composite plates by two new displacement based quadrilateral plate Elements
Composite Structures, 2006Co-Authors: Y. X. Zhang, K.s. KimAbstract:Abstract Two simple displacement-based 4-node quadrilateral Elements RDKQ-NL20 and RDKQ-NL24 are developed in this paper for geometrically nonlinear analysis of thin to moderately thick laminated composite plates. The proposed quadrilateral nonlinear laminated composite plate Elements are based on the first-order shear deformation theory (FSDT) and von-Karman’s large deflection theory, and the total Lagrangian approach is employed to formulate the Elements. The deflection and rotation functions of the Element boundary are obtained from Timoshenko’s laminated composite beam functions, thus convergence can be ensured theoretically for very thin laminates. The linear displacement interpolation functions of the standard 4-node quadrilateral isoparametric Plane Element and the in-Plane displacement functions of a quadrilateral Plane Element with drilling degrees of freedom are taken as the in-Plane displacements of Elements RDKQ-NL20 and RDKQ-NL24, respectively. The developed Elements are simple in formulation, free from shear-locking, and include conventional engineering degrees of freedom. Numerical examples demonstrate that they are accurate and efficient for large deformation, small rotation nonlinear analysis of thin to moderately thick laminated composite plates.
-
a refined non linear non conforming triangular plate shell Element
International Journal for Numerical Methods in Engineering, 2003Co-Authors: Y. X. Zhang, Y K CheungAbstract:A refined non-conforming triangular plate/shell Element for geometric non-linear analysis of plates/shells using the total Lagrangian/updated Lagrangian approach is constructed in this paper based on the refined non-conforming Element method for geometric non-linear analysis. The Allman's triangular Plane Element with vertex degrees of freedom and the refined triangular plate-bending Element RT9 are used to construct the present Element. Numerical examples demonstrate that the accuracy of the new Element is quite high in the geometric non-linear analysis of plates/shells. Copyright © 2003 John Wiley & Sons, Ltd.
Mingjue Zhou - One of the best experts on this subject based on the ideXlab platform.
-
A 4-node hybrid stress-function (HS-F) Plane Element with drilling degrees of freedom less sensitive to severe mesh distortions
Computers & Structures, 2011Co-Authors: Song Cen, Mingjue ZhouAbstract:A simple but robust 4-node hybrid stress-function (HS-F) membrane Element with drilling degrees of freedom is developed based on the principle of minimum complementary energy. Its stress fields are derived from the first seven fundamental analytical solutions of the Airy stress function. The assumed displacements along Element boundaries employ compatible mode of Allman for which the nodal drilling degrees of freedom are considered. Numerical results show that the proposed new Element, denoted as HSF-Q4@q-7@b, exhibits much improved numerical accuracy and robust performance. In particular, the Element performs well even when the Element shape degenerates into a triangle or concave quadrangle.