No Cover Image

Journal article 571 views 129 downloads

An unsymmetric 8-node hexahedral element with high distortion tolerance

Pei-Lei Zhou, Song Cen, Jun-Bin Huang, Chen-Feng Li, Qun Zhang, Chenfeng Li Orcid Logo

International Journal for Numerical Methods in Engineering

Swansea University Author: Chenfeng Li Orcid Logo

DOI (Published version): 10.1002/nme.5318

Abstract

Among all 3D 8-node hexahedral solid elements in current finite element library, the ‘best’ one can produce good results for bending problems using coarse regular meshes. However, once the mesh is distorted, the accuracy will drop dramatically. And how to solve this problem is still a challenge that...

Full description

Published in: International Journal for Numerical Methods in Engineering
Published: 2016
URI: https://cronfa.swan.ac.uk/Record/cronfa29376
Tags: Add Tag
No Tags, Be the first to tag this record!
Abstract: Among all 3D 8-node hexahedral solid elements in current finite element library, the ‘best’ one can produce good results for bending problems using coarse regular meshes. However, once the mesh is distorted, the accuracy will drop dramatically. And how to solve this problem is still a challenge that remains outstanding. This paper develops an 8-node, 24-DOF (three conventional DOFs per node) hexahedral element based on the virtual work principle, in which two different sets of displacement fields are employed simultaneously to formulate an unsymmetric element stiffness matrix. The first set simply utilizes the formulations of the traditional 8-node trilinear isoparametric element, while the second set mainly employs the analytical trial functions in terms of 3D oblique coordinates (R, S, T). The resulting element, denoted by US-ATFH8, contains no adjustable factor and can be used for both isotropic and anisotropic cases. Numerical examples show it can strictly pass both the first-order (constant stress/strain) patch test and the second-order patch test for pure bending, remove the volume locking, and provide the invariance for coordinate rotation. Especially, it is insensitive to various severe mesh distortions.
College: College of Engineering