Four-Node Quadrilateral Shell Element MITC4

2016 ◽  
Vol 825 ◽  
pp. 99-104 ◽  
Author(s):  
Edita Dvořáková ◽  
Bořek Patzák
Keyword(s):  
Three Dimensional ◽  
Shell Element ◽  
Thin Shells ◽  
Element Formulation ◽  
Finite Element Code ◽  
Shear Locking ◽  
Benchmark Problem ◽  
Quadrilateral Element ◽  
Shell Elements ◽  
Continuum Description

Four-node quadrilateral element MITC4 applicable to both thick and thin shells is presented. The element formulation starts from three-dimensional continuum description degenerated to shell behavior. Shear locking, which is common problem in analysis of thin shells, is overcome by the use of MITC (Mixed Interpolation of Tensorial Components) approach. Element has been implemented into finite element code OOFEM and its performance is demonstrated on Scordelis-Lo shell, a benchmark problem frequently used in the evaluation of shell elements.

A Finite Element for the Analysis of Shell Intersections

1996 ◽  
Vol 118 (4) ◽  
pp. 399-406 ◽  
Author(s):  
W. J. Koves ◽  
S. Nair
Keyword(s):  
Finite Element ◽  
Stress State ◽  
Three Dimensional ◽  
Shell Element ◽  
Theory Of Elasticity ◽  
Shell Elements ◽  
Asme Code ◽  
Form Theory ◽  
Computation Scheme ◽  
Shell Intersections

A specialized shell-intersection finite element, which is compatible with adjoining shell elements, has been developed and has the capability of physically representing the complex three-dimensional geometry and stress state at shell intersections (Koves, 1993). The element geometry is a contoured shape that matches a wide variety of practical nozzle configurations used in ASME Code pressure vessel construction, and allows computational rigor. A closed-form theory of elasticity solution was used to compute the stress state and strain energy in the element. The concept of an energy-equivalent nodal displacement and force vector set was then developed to allow complete compatibility with adjoining shell elements and retain the analytical rigor within the element. This methodology provides a powerful and robust computation scheme that maintains the computational efficiency of shell element solutions. The shell-intersection element was then applied to the cylinder-sphere and cylinder-cylinder intersection problems.

Comparison of Three-Dimensional Flexible Beam Elements for Dynamic Analysis: Classical Finite Element Formulation and Absolute Nodal Coordinate Formulation

2009 ◽  
Vol 5 (1) ◽  
Author(s):  
A. L. Schwab ◽  
J. P. Meijaard
Keyword(s):  
Dynamic Analysis ◽  
Absolute Nodal Coordinate Formulation ◽  
Three Dimensional ◽  
Flexible Beam ◽  
Element Formulation ◽  
Shear Locking ◽  
Elastic Line ◽  
Absolute Nodal Coordinate ◽  
Beam Elements ◽  
Bending Mode

Three formulations for a flexible spatial beam element for dynamic analysis are compared: a Timoshenko beam with large displacements and rotations, a fully parametrized element according to the absolute nodal coordinate formulation (ANCF), and an ANCF element based on an elastic line approach. In the last formulation, the shear locking of the antisymmetric bending mode is avoided by the application of either the two-field Hellinger–Reissner or the three-field Hu–Washizu variational principle. The comparison is made by means of linear static deflection and eigenfrequency analyses on stylized problems. It is shown that the ANCF fully parametrized element yields too large torsional and flexural rigidities, and shear locking effectively suppresses the antisymmetric bending mode. The presented ANCF formulation with the elastic line approach resolves most of these problems.

Locking Behavior of Isoparametric Curved Beam Finite Elements

1995 ◽  
Vol 48 (11S) ◽  
pp. S25-S29 ◽  
Author(s):  
Miguel Luiz Bucalem ◽  
Klaus-Ju¨rgen Bathe
Keyword(s):  
Shell Element ◽  
Beam Element ◽  
Curved Beam ◽  
Shear Locking ◽  
Shell Elements ◽  
One Dimensional ◽  
Curved Beam Element ◽  
The One ◽  
Insight Into ◽  
The Continuum

We present a study of the membrane and shear locking behavior in an isoparametric curved beam element. The objective is to gain insight into the locking phenomenon, specially membrane locking, of continuum based degenerated shell elements. This is possible since the isobeam element is the one-dimensional analogue of the continuum based shell element. In this context, reduced integration and mixed interpolation schemes are briefly examined. Such a study can be a valuable aid when developing new shell elements.

Element-Independent Pure Deformational and Co-Rotational Methods for Triangular Shell Elements in Geometrically Nonlinear Analysis

2018 ◽  
Vol 18 (05) ◽  
pp. 1850065 ◽  
Author(s):  
Y. Q. Tang ◽  
Y. P. Liu ◽  
S. L. Chan
Keyword(s):  
Nonlinear Analysis ◽  
Nonlinear Problems ◽  
Shell Element ◽  
Benchmark Problems ◽  
Element Formulation ◽  
Geometrically Nonlinear ◽  
Plate Element ◽  
Membrane Element ◽  
Geometrically Nonlinear Analysis ◽  
Shell Elements

Proposed herein is a novel pure deformational method for triangular shell elements that can decrease the element quantities and simplify the element formulation. This approach has computational advantages over the conventional finite element method for linear and nonlinear problems. In the element level, this method saves time for computing stresses, internal forces and stiffness matrices. A flat shell element is formed by a membrane element and a plate element, so that the pure deformational membrane and plate elements are derived and discussed separately in this paper. Also, it is very convenient to incorporate the proposed pure deformational method into the element-independent co-rotational (EICR) framework for geometrically nonlinear analysis. Thus, on the basis of the pure deformational method, a novel EICR formulation is proposed which is simpler and has more clear physical characteristics than the traditional formulation. In addition, a triangular membrane element with drilling rotations and the discrete Kirchhoff triangular plate element are used to verify the proposed pure deformational method, although several benchmark problems are employed to verify the robustness and accuracy of the proposed EICR formulations.

Calculation of Shell Element Failure Based on the State of Stress Inside of a Neck

2015 ◽  
Author(s):  
R. C. Dragt ◽  
J. Kraus ◽  
C. L. Walters
Keyword(s):  
Three Dimensional ◽  
Shell Element ◽  
Offshore Structures ◽  
Shell Elements ◽  
Thin Walled Structures ◽  
Coulomb Failure ◽  
Correct Determination ◽  
Element Failure ◽  
The Relationship

Simulation of failure in thin-walled structures is critical for the correct determination of crash performance of ships and offshore structures. Typically, shell elements are used, but these elements are not able to adequately capture local failure, especially inside of a neck. This paper addresses these gaps by adapting the Bridgman (1952) model of a neck inside of a plate by making it three-dimensional and offering an estimate of the relationship between state parameters of a shell element and the geometry inside of a neck. Finally, recommendations are also made about how to interface this information with the Modified Mohr-Coulomb failure locus to create a practical algorithm for assessing failure in shell elements.

Shell Element Formulation Based Finite Element Modeling, Analysis and Experimental Validation of Incremental Sheet Forming Process

2015 ◽  
Author(s):  
Govind N. Sahu ◽  
Sumit Saxena ◽  
Prashant K. Jain ◽  
J. J. Roy ◽  
M. K. Samal ◽  
...  
Keyword(s):  
Finite Element ◽  
Thickness Distribution ◽  
Shell Element ◽  
Time Profile ◽  
Experimental Results ◽  
Computational Time ◽  
Element Formulation ◽  
Forming Process ◽  
Element Analysis ◽  
Shell Elements

This paper presents the effect of shell element formulations on the response parameters of incremental sheet metal forming process. In this work, computational time, profile prediction and thickness distribution are investigated by both finite element analysis and experimentally. The experimental results show that the thickness distribution is in good agreement with the results obtained with Belytschko-Tsay (BT) and Improved Flanagan-Belytschko (IFB) shell element formulations. These two shell element formulations do trade-off between computational time and accuracy. For more accurate results, the BT shell element formulation is better and for less computational time with good results, the IFB shell element is preferable. Finally, BT shell element formulation has been chosen for FE Analysis of ISF process in HyperWorks, since the results of thickness distribution and profile prediction is in better agreement with the experimental results as well as the computational time is less among the shell elements.

scholarly journals EAS 3D triangular and quadrangular shell elements

2010 ◽  
pp. 205-215
Author(s):  
Philippe Jetteur ◽  
Philippe Pasquet
Keyword(s):  
Degrees Of Freedom ◽  
Shell Element ◽  
Element Formulation ◽  
Shell Elements ◽  
Assumed Strain ◽  
Definition Of ◽  
3D Solid ◽  
Assumed Strain Method ◽  
Internal Degrees Of Freedom

A new 3D solid shell element is developed in SAMCEF™ code. The purpose of this element is to make the meshing easier starting from a 3D definition of the structure, it is not necessary to extract the mean surface of the shell. Here, we are not concerned by the meshing; we only are concerned by the element formulation. In order to improve the quality of the results, we add internal degrees of freedom as suggested by Simo and co-authors. We use the Enhanced Assumed Strain method. A special handling of the transverse shear is performed in order to pass successfully the plate patch test (constant bending) and to avoid shear locking. The formulation is based on the work of Bathe and Dvorkin for classical shell. The element has been developed in linear and non-linear analysis; it can be a mono or multilayer element.

scholarly journals Robustness of Hierarchical Laminated Shell Element Based on Equivalent Single-Layer Theory

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Jae S. Ahn ◽  
Seung H. Yang ◽  
Kwang S. Woo
Keyword(s):  
Three Dimensional ◽  
Single Layer ◽  
Laminated Composite ◽  
Shell Element ◽  
Linear Mapping ◽  
Large Radius ◽  
Laminated Shell ◽  
Shell Elements ◽  
Aspect Ratios ◽  
Material Conditions

This paper deals with the hierarchical laminated shell elements with nonsensitivity to adverse conditions for linear static analysis of cylindrical problems. Displacement approximation of the elements is established by high-order shape functions using the integrals of Legendre polynomials to ensureC0continuity at the interface between adjacent elements. For exact linear mapping of cylindrical shell problems, cylindrical coordinate is adopted. To find global response of laminated composite shells, equivalent single-layer theory is also considered. Thus, the proposed elements are formulated by the dimensional reduction from three-dimensional solid to two-dimensional plane which allows the first-order shear deformation and considers anisotropy due to fiber orientation. The sensitivity tests are implemented to show robustness of the present elements with respect to severe element distortions, very high aspect ratios of elements, and very large radius-to-thickness ratios of shells. In addition, this element has investigated whether material conditions such as isotropic and orthotropic properties may affect the accuracy as the element distortion ratio is increased. The robustness of present element has been compared with that of several shell elements available in ANSYS program.

A Parametric Study for Four Node Bilinear EAS Shell Elements

2010 ◽  
Vol 26 (4) ◽  
pp. 431-438
Author(s):  
Cengiz Polat
Keyword(s):  
Variational Principle ◽  
Transverse Shear ◽  
Strain Field ◽  
Shell Element ◽  
Shell Structures ◽  
Shear Locking ◽  
Shell Elements ◽  
Assumed Strain ◽  
Dependent Strain ◽  
Transverse Shear Locking

ABSTRACTA locking free formulation of 4-node bilinear shell element and its application to shell structures is demonstrated. The Enhanced Assumed Strain (EAS) method based on three-field variational principle of Hu-Washizu is used in the formulation. Transverse shear locking and membrane locking are circumvented by means of enhancing the displacement-dependent strain field with extra assumed strain field. Several benchmark shell problems are analyzed.

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