A Discontinuity-Enriched Finite Element Method for Dynamic Multiple Crack Growth in Brittle Materials

A Discontinuity-Enriched Finite Element Method for Dynamic Multiple Crack Growth in Brittle Materials

Zhang, Jujian (TU Delft Civil Engineering & Geosciences)

van der Meer, F.P. (mentor)
Aragon, A.M. (graduation committee)
Sluys, Lambertus J. (graduation committee)

Delft University of Technology

Civil Engineering

2023-07-13

This thesis introduces the Discontinuity-Enriched Finite Element Method (DE-FEM) for the modeling of dynamic multiple crack growth problems including branching and merging, as an alternative to eXtended/Generalized Finite Element Method (X/GFEM). DE-FEM differs from X/GFEM by placing the enriched degrees of freedom (DOFs) directly along the discontinuities, and the enrichment functions vanish at standard mesh nodes. This approach allows DE-FEM to preserve the physical meaning of standard mesh nodes and avoid the issues associated with blending elements. Moreover, by adding enrichment directly along the discontinuities, DE-FEM is more straightforward in computer implementation. These properties of DE-FEM facilitate its modeling of complex crack configurations such as the dynamic crack propagation problems with multiple cracks. Here we propose a scheme for dynamic multiple crack propagation using DE-FEM, which covers crack initiation, propagation, and interaction. Numerical examples are provided to validate the effectiveness of DE-FEM in capturing crack patterns that are similar to those observed in other studies. Meanwhile, the reasons for the numerical instabilities observed during crack propagation and methods to mitigate them are also discussed.

Discontinuity-Enriched Finite Element Method
Linear Elastic Fracture Mechanics
Dynamic crack propagation
Stress intensity factors
Crack branching
Crack coalescence
Time integration

http://resolver.tudelft.nl/uuid:ab1be6d8-9ec4-4514-ac55-0cfc987d034e

2025-01-13

Student theses

master thesis

© 2023 Jujian Zhang