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Title:IGFEM-based reduced-order modeling and design of nonlinear composites
Author(s):Brandyberry, David
Director of Research:Geubelle, Philippe H
Doctoral Committee Chair(s):Geubelle, Philippe H
Doctoral Committee Member(s):James, Kai; Tortorelli, Daniel; Zhang, Xiang
Department / Program:Aerospace Engineering
Discipline:Aerospace Engineering
Degree Granting Institution:University of Illinois at Urbana-Champaign
Degree:Ph.D.
Genre:Dissertation
Subject(s):Reduced-order model
optimization
generalized finite element
Abstract:Motivated by significant advances in manufacturing, development of powerful computational techniques, and increases in computational capacity, the design of material microstructures with specific macroscopic behaviors has been investigated over the past two decades. The main challenges with the solution of these inverse problems is the computational cost associated with modeling the mechanical behavior of complex domains as optimization algorithms are usually iterative, requiring many evaluations of the domain response. For this reason, the majority of existing work on this subject focuses on linear theory. In this work, a powerful nonlinear solver to model the failure of composite materials is developed using an Interface-enriched Generalized Finite Element Method (IGFEM). Cohesive interfacial failure and damage mechanisms in the constituents are the primary source of nonlinearity and the shape of material interfaces and nonlinear damage parameters are the key design variables used to obtain desired nonlinear macroscopic behaviors. Several three-dimensional particulate composite periodic unit cells are optimized to demonstrate the flexibility of IGFEM in the shape optimization process due to its use of a non-conforming mesh. A reduced-order model based on integrating the IGFEM with the Eigendeformation-based reduced-order Homogenization Method (EHM) is then formulated to relieve the extreme computational cost of these large three-dimensional nonlinear finite element evaluations. A multi-resolution optimization scheme is presented to produce microstructure designs near the optimum quickly with the IGFEM-based EHM that are later refined with a high fidelity IGFEM-based optimizer. The damage parameters of several three-dimensional particulate composite microstructures are then designed using this method, showing dramatic deceases in the computational cost and improvements in the final designed material.
Issue Date:2020-10-13
Type:Thesis
URI:http://hdl.handle.net/2142/109478
Rights Information:Copyright 2020 David Robert Brandyberry
Date Available in IDEALS:2021-03-05
Date Deposited:2020-12


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