Department of Mechanics: Seminar: Abstract Evangelista 2016

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Francisco Evangelista Junior, Ph.D., Department of Civil and Environmental Engineering, University of Brasília (UnB), Brazil

A Two-Scale Approach to Predict Multi-Site Damage Cracking Potential in 3D Structures Using the Generalized Finite Element Method

This presentation shows the author and co-workers’ recent advances of multi-scale methods, especially global-local approaches, through the generalized finite element method framework. Some results extends the global-local approach to a broader class of 3D fracture problems involving realistic boundary conditions and the existence of multiple cracks of different orders of magnitude in size within multiple regions of the domain. The proposed global-local enrichment functions allow the kinematics to be represented in the global domain through enrichment function from the local problems rather than explicitly modeling each crack discretely in the global domain. This strategy makes it possible to solve realistic multi-site damage fracture problems that traditional numerical methods generally cannot tackle due to numerical round off errors governed by the large size domain and very refined crack fronts. Furthermore, the employed global-local approach significantly reduces the computational costs for large-scale problems involving million degrees-of-freedom. This demonstrates that the proposed strategy provides an efficient platform to simulate larger problems saving significant computational time. Some recent research and results in 2-D crack propagation using a continuous-discontinuous framework is also presented. In this approach, a cohesive zone model is used along with a continuum damage framework to predict mode I and mixed mode crack propagation in notched and smooth surfaces without remeshing.

Dr. Evangelista Jr holds a doctorate from the University of Illinois at Champaign-Urbana since 2011. He was an assistant professor at California State University, Los Angeles, from 2012 to 2013; and is currently an associate professor at the University of Brasilia (UnB), Brazil, teaching and researching at the Structural Engineering Graduate Program in the Department of Civil and Environmental Engineering. His main research interests are on structures, materials and geomechanics, specifically constitutive and computational modeling of fracture mechanics process; advanced characterization of viscoelastic materials; computational mechanics using traditional finite element methods and meshless approaches; and stochastic modeling of structures and engineering systems.