Generalized conforming plate bending elements using point and line compatibility conditions
ABSTRACT Based on the modified potential energy functional and the point and line compatibility conditions, two generalized conforming elements (triangular with 9 DOFs and rectangular with 12 DOFs) for thin plate bending are developed. The proposed elements are reliable, easy to formulate and exhibit excellent performance.
- SourceAvailable from: Senthilkumar Vaiyapuri
[Show abstract] [Hide abstract]
- "The search for robust quadrilateral membrane elements which can pass the patch test, remove parasitic shear and Poisson's ratio stiffening, and are insensitive to mesh distortion, has been going on for nearly fifty years. Recently, there has been renewed interest in the formulation of quadrilateral membrane elements based on the area coordinates, use of internal parameters and the generalized conforming method      . "
ABSTRACT: The introduction of the quadrilateral area coordinate (QAC) membrane elements has generated more heat than light on the subject of why distorted membrane elements perform very poorly. The canonical guidelines for construction of robust elements are continuity and completeness. It is known that isoparametric (or parametric) quadrilateral membrane elements satisfy the continuity requirements always. In rectangular form, they perform extremely well, except in cases where parasitic shear is involved (plane stress modeling of bending of thin beams). So their poor performance when the elements are used in general (i.e. distorted) quadrilateral form is now attributed to the failure to accommodate the completeness requirements. Completeness is understood to be maintained in physical (i.e. Cartesian, or metric) space and not in the natural (i.e. parametric) space. The QAC approach is a compromise that tries to use shape functions which are in physical space, but as these cannot ensure exact continuity, require a relaxed generalized continuity to be imposed. However, here, the patch test cannot be ensured in the strictest sense as a careful examination of the results from various QAC elements in this paper will reveal. Even this is not enough to remove locking in the simpler 4-node elements and additional displacements fields have to be introduced through internal parameters to ensure what Prathap calls the consistency requirement. These issues are carefully studied in this investigation.Computer Methods in Applied Mechanics and Engineering 09/2008; 197(49):4379-4382. DOI:10.1016/j.cma.2008.05.007 · 2.63 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: A refined non-conforming quadrilateral thin plate bending element RPQ4 which can satisfy the requirement of convergence is established such that the non-conforming displacement function can be derived directly. A simple explicit expression of a refined constant strain matrix can be introduced into the formulation of the standard displacement element which results in the constraint condition of interelement continuity being satisfied in an average sense. Numerical examples are presented to show that the present model can pass the patch test and possesses high accuracy. © 1997 John Wiley & Sons, Ltd.International Journal for Numerical Methods in Engineering 11/1997; 40(21):3919 - 3935. DOI:10.1002/(SICI)1097-0207(19971115)40:21<3919::AID-NME243>3.0.CO;2-A · 1.96 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: In order to improve the accuracy of the original quadrilateral discrete Kirchhoff thin plate bending element DKQ a simple explicit expression of refined constant strain matrix can be introduced into its formulation so as to establish a refined element RDKQ. Numerical examples are presented to show that the present model indeed possesses higher accuracy. © 1997 John Wiley & Sons, Ltd.International Journal for Numerical Methods in Engineering 11/1997; 40(21):3937 - 3953. DOI:10.1002/(SICI)1097-0207(19971115)40:21<3937::AID-NME247>3.0.CO;2-2 · 1.96 Impact Factor