2026-09-20T00:41:06Z https://www.ideals.illinois.edu/oai-pmh

oai:www.ideals.illinois.edu:2142/109478 2023-07-11 col_2142_5131 col_2142_14800 com_2142_5130 com_2142_14799 com_2142_234

Geubelle, Philippe H Geubelle, Philippe H James, Kai Tortorelli, Daniel Zhang, Xiang Brandyberry, David 2021-03-05T21:40:36Z 2021-03-05T21:40:36Z 2023-03-05T21:43:00Z 2020-10-13 2020-12 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. Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2022-12-01 The student, David Brandyberry, accepted the attached license on 2020-09-29 at 19:09. The student, David Brandyberry, submitted this Dissertation for approval on 2020-09-29 at 19:10. This Dissertation was approved for publication on 2020-10-13 at 14:51. DSpace SAF Submission Ingestion Package generated from Vireo submission #15821 on 2021-03-04 at 16:18:52 Made available in DSpace on 2021-03-05T21:40:36Z (GMT). No. of bitstreams: 2 BRANDYBERRY-DISSERTATION-2020.pdf: 76800864 bytes, checksum: e2ae40716f2d45b51cb2a0da3d9abc4f (MD5) LICENSE.txt: 4214 bytes, checksum: c15af6ad3af31aba72894f2d3d2d9e2c (MD5) Previous issue date: 2020-10-13 Embargo set by: Seth Robbins for item 117182 Lift date: 2023-03-05T21:40:52Z Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD system Embargo set by: Seth Robbins for item 117182 Lift date: 2023-03-05T21:43:00Z Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD system Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD system U of I Only application/pdf http://hdl.handle.net/2142/109478 en Copyright 2020 David Robert Brandyberry Reduced-order model optimization generalized finite element IGFEM-based reduced-order modeling and design of nonlinear composites text Thesis Aerospace Engineering Aerospace Engineering University of Illinois at Urbana-Champaign Dissertation Ph.D.