This paper analyzes a nonconforming 5-node quadrilateral transition finite element for Poisson equation.This element was originally proposed by Choi and Park[Computers and Structures,32(1989),pp.295–304 and Thin-Walled Structures,28(1997),pp.1–20]for the analysis of Mindlin plates.We show the consistency error of this element is only O(h^(1/2))over the transition edges of the quadrilateral subdivision.By modifying the shape functions with respect to mid-nodes,we get an improved version of the element for which the consistency error is O(h).Numerical examples are provided to verify the theoretical results.
In this paper,an energy-compatibility condition is used for stress optimization in the derivation of new accurate 8-node hexahedral elements for threedimensional elasticity.Equivalence of the proposed hybrid method to an enhanced strains method is established,which makes it easy to extend the method to general nonlinear problems.Numerical tests show that the resultant elements possess high accuracy at coarse meshes,are insensitive to mesh distortions and free from volume locking in the analysis of beams,plates and shells.
