Defesas marcadas - Dissertações defendidas - Teses defendidas

Data: 27/09/2017 - Horário: 10:00
Local: sala 4409
Aluna: Mariana Pimenta Alves
Orientador(a): Carlos Alberto Cimini Jr.
Título: Effect of In-Plane Fiber Waviness in Unidirectional CFRP Composites
Banca:
Prof. Dr. Carlos Alberto Cimini Jr. (DEES - UFMG)
Prof. Dr. Estevam Barbosa de Las Casas (DEES - UFMG)
Prof. Dr. Túlio Hallak Panzera (UFSJ)


Resumo:

This work consists of an investigation of the effects of fiber waviness in key structural properties of carbon fiber reinforced composites. Fiber waviness is a type of manufacturing defect commonly found in composite material parts. Finite element modeling using the commercial platform Abaqus® was performed to simulate unidirectional laminae containing in-plane graded undulations in the shape of sinusoidal waves. The peak misalignment angle was taken as sole influence parameter. Automated model generation was performed through the use of parametric Python scripting. Composites were subjected to in-plane loading and boundary conditions, with analyses being divided into uniaxial normal longitudinal/transverse and biaxial normal loads. Results proved that fiber curvature affects local stresses distribution, leading to stress concentration/relaxation and inducing the occurrence of local stresses other than the original ones found in plates with no defect. The influence on effective elastic modulus was less significant than on strength values. Initial failure was predicted by Hashin failure criterion, which distinguishes between fiber and matrix failure. A strength knockdown effect was observed as misalignment angle increased, favouring a matrix dominated failure mode. Longitudinal load cases presented a higher strength reduction than observed on transverse loading. Regarding biaxial loads, the case of longitudinal tension + transverse compression was the most severely affected in terms of failure; the case of longitudinal compression + transverse tension was the least susceptible one. The goal was to provide a computationally efficient analysis framework to support decisions in quality control.

Data: 16/10/2017 - Horário: 14:00
Local: Sala 4409
Aluna: Maryam Ramezani
Orientador(a): Estevam Barbosa de Las Casas
Co-Orientador(a): Osvaldo Luís Manzoli
Título: Modeling of Crack Propagation in a Premolar Tooth Using Finite Element Method
Banca:
Prof. Dr. Estevam Barbosa de Las Casas (DEES - UFMG)
Prof. Dr. Osvaldo Luís Manzoli - Coorientador (UNESP)
Prof. Dr. Felício Bruzzi Barros (DEES - UFMG)
Profa. Dra. Claudia Machado de Almeida Mattos (UFES)


Resumo:

The term cracked tooth syndrome refers to an incomplete fracture of a vital posterior tooth that involves the dentin and occasionally extends into the pulp. To better understand fracture characteristics of a premolar tooth, the cracked tooth syndrome will be studied here by using computational techniques. The first step for the analysis is the development of a 3D geometric model to serve as the basis for a finite element analysis. This model, generated from a commercial code, will be exported to a crack propagation program. By having the 3D model and choosing an appropriate crack propagation technique that fits the problem, one can define the material properties and loading types and conduct the crack propagation procedure under various loading conditions. Finally, the numerically obtained results can be compared with clinical results obtained from the literature.

Data: 26/09/2017 - Horário: 14:00
Local: sala 4409
Aluno: Bruno Cesarino Soares
Orientador(a): Felício Bruzzi Barros
Co-Orientador(a): José Ricardo Queiroz Franco
Título: Automação do Processo Análise Limite e de "Shakedown" de Vasos de Pressão Via Modelagem BIM
Banca:
Prof. Dr. Ricardo Hallal Fakury (DEES - UFMG)
Profa. Dr. Lavínia Maria Sanabio Borges (UFRJ)
Profa. Dr. Renata Maria Abrantes Baracho Porto (ECI - UFMG)

Data: 29/09/2017 - Horário: 13:00
Local: Sala 4409
Aluno: Leandro Lopes da Silva
Orientador(a): Roque Luiz da Silva Pitangueira
Título: Análise Multiescala de Meios Parcialmente Frágeis Utilizando Descrição Micromórfica do Contínuo
Banca:
Prof. Dr. Felício Bruzzi Barros (DEES - UFMG)
Prof. Dr. Samuel Silva Penna (DEES - UFMG)
Prof. Dr. Raul Rosas e Silva (PUC - RIO)