A generalized finite element method for three-dimensional fractures in fiber-reinforced composites

Alves, Phillipe Daniel

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https://hdl.handle.net/2142/109628 Copy

Description

Title

A generalized finite element method for three-dimensional fractures in fiber-reinforced composites

Author(s)

Alves, Phillipe Daniel

Issue Date

2020-12-03

Director of Research (if dissertation) or Advisor (if thesis)

Duarte, Carlos A

Doctoral Committee Chair(s)

Duarte, Carlos A

Committee Member(s)

• Geubelle, Philippe H
• Lopez-Pamies, Oscar
• Simone, Angelo

Department of Study

Civil & Environmental Eng

Discipline

Civil Engineering

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

Ph.D.

Degree Level

Dissertation

Keyword(s)

Generalized Finite Element Method Fiber-Reinforced Composites

Abstract

Fiber reinforcements are used in a broad variety of materials in engineering. They increase the strength, stiffness, ductility, and resistance to fatigue of the unreinforced material. Computational simulations can reduce the cost of designing these materials, and improve the understanding of their failure mechanisms. However, modeling of damage evolution and the multiscale interactions in composite materials using standard Finite Element Methods (FEMs) face significant barriers in terms of model generation and problem size. This work presents recent advances of the Generalized Finite Element Method (GFEM) for three-dimensional modeling and simulation of crack propagation in fiber-reinforced composites. Fibers are discretely modeled using a modified formulation of the Embedded Reinforcement with bond Slip (mERS) that allows its combination with the GFEM where fractures are represented using enrichment functions instead of meshes fitting the crack surface. Matrix cracks are described using discontinuous and singular functions as in the GFEM for homogeneous materials. This procedure can address some of the limitations of existing FEMs by describing both cracks and fibers independently of the underlying FEM mesh. Examples illustrating the capabilities and robustness of the method are presented. Crack propagation simulations are compared to physical tests showing that the method can successfully reproduce the failure behavior of fiber-reinforced composites. The results show that several failure mechanisms of the composite can be reproduced by the model, including matrix crack propagation, fiber debonding, and failure. In addition a multiscale approach is proposed using the GFEMgl, a framework that allows intercommunication between macro and micro scales of the material.

Graduation Semester

2020-12

Type of Resource

Thesis

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http://hdl.handle.net/2142/109628

Copyright and License Information

Copyright 2020 Phillipe Alves

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