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Title:A multiscale computational framework for the simulation of local features in large structures
Author(s):Li, Haoyang
Director of Research:Duarte, Carlos Armando
Doctoral Committee Chair(s):Duarte, Carlos Armando
Doctoral Committee Member(s):Masud, Arif; Olson, Luke; Eason, Thomas, III G.
Department / Program:Civil & Environmental Eng
Discipline:Civil Engineering
Degree Granting Institution:University of Illinois at Urbana-Champaign
Degree:Ph.D.
Genre:Dissertation
Subject(s):Generalized Finite Element Method (GFEM)
Extended Finite Element Method
Multiscale
Multiphysics
Parallel
Thermomechanical
Plasticity
Fracture mechanics
Stress intensity factor
Spot welds
Iterative Global-Local
Non-intrusive coupling
Co-simulation
Abstract:In many engineering applications, it is necessary to account for interactions among multiple spatial scales through numerical simulations. Resolving fine-scale features such as geometrical details, cracks, and localized nonlinearities with high fidelity is crucial for the accurate prediction of the response and service life of structural components. Three-dimensional models with detailed meshes and advanced modeling techniques are usually required to accurately capture fine scale responses. However, adopting such models on the structural/global scale is computationally inefficient and sometimes unfeasible for problems involving a large number of local features. In most engineering applications, coarse 3-D or shell models are often sufficient for predicting the global response and hence are commonly adopted at the global scale. On the other hand, in critical regions, 3-D solid models and adaptive discretization methods are needed to capture fine-scale phenomena. Thus, the challenge lies in how to efficiently link models and discretizations at different scales. This work presents a multiscale computational framework based on the Generalized/eXtended Finite Element Method with global--local enrichments (GFEMgl) and the iterative global—local (IGL) method aiming at capturing localized responses with high accuracy and computational efficiency. In this framework, the GFEMgl is capable of capturing localized thermomechanical responses on coarse meshes via enrichment functions provided by parallel simulations of local boundary value problems where local features are accurately modeled and resolved. The IGL, in turn, provides a robust and non-intrusive approach to establishing a two-way coupling between global and fine-scale models. Additionally, as many closed- and open-source simulation tools are being developed nowadays, this framework enables engineers to perform co-simulation with multiple solvers based on the desired computational capabilities at different scales. A series of systematic numerical studies are conducted on a range of three-dimensional applications involving material nonlinearities, multiphysics responses, and fractures. Various attributes of the framework are assessed on benchmark problems and compared against reference numerical methods. The results show that the proposed methodology can deliver high fidelity solutions comparable to those obtained from a direct finite element analysis while offering promising computational efficiency. In addition, it is demonstrated that the user-time required for setting up models and discretizations for large representative problems can be noticeably reduced by utilizing the proposed framework.
Issue Date:2020-05-08
Type:Thesis
URI:http://hdl.handle.net/2142/108335
Rights Information:Copyright 2020 Haoyang Li
Date Available in IDEALS:2020-08-27
Date Deposited:2020-05


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