Abstract
For integrals with various orders of vertex singularity encountered in the generalized/extended finite element method, three difficulties should be concerned as: (a) the singularity with respect to local distance r; (b) the near singularity caused by ill-shaped patches; (c) the near singularity during the iso-parametric transformation. In this paper, based on the Duffy transformation, the near singularities caused by ill-shaped patches and element shape distortion are revealed theoretically and numerically, a Duffy-distance transformation is constructed to damp out the near singularity caused by ill-shaped patches, and a conformal preconditioning strategy is developed to fully eliminate the near singularity caused by element shape distortion. Extensive numerical examples, including crack-tip elements with distorted shape, are given to validate the efficiency and robustness of the presented scheme in this paper.
Original language | English |
---|---|
Pages (from-to) | 559-576 |
Number of pages | 18 |
Journal | Computer Methods in Applied Mechanics and Engineering |
Volume | 340 |
DOIs | |
Publication status | Published - 2018 Oct 1 |
Externally published | Yes |
Bibliographical note
Funding Information:The authors acknowledge the financial support from the National Natural Science Foundation of China (Nos. 51621006 , 51509240 , 41731284 and 11672360 ).
Publisher Copyright:
© 2018 Elsevier B.V.
Keywords
- Conformal preconditioning
- Duffy transformation
- Numerical quadrature
- Weak singularity
- XFEM
ASJC Scopus subject areas
- Computational Mechanics
- Mechanics of Materials
- Mechanical Engineering
- General Physics and Astronomy
- Computer Science Applications