Banca de QUALIFICAÇÃO: Leonardo Bernardo e Silva

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : Leonardo Bernardo e Silva
DATE: 26/07/2023
TIME: 14:00
LOCAL: Plataforma Microsoft Teams
TITLE:

Analysis of fretting problems in anisotropic materials using the boundary element method

KEY WORDS:

Boundary element method, fatigue life estimation, anisotropic materials, contact
problems, fretting fatigue.

PAGES: 86
BIG AREA: Engenharias
AREA: Engenharia Mecânica
SUMMARY:

The main objective of this thesis is the development of a formulation based on the Boundary
Element Method is used for analysis of 2D contact problems in anisotropic materials under
cyclic loads. Discontinuous quadratic boundary elements are used whose degrees of freedom
are written in a local reference system, where the directions of the coordinate axes coincide
with the normal and tangent directions to the contour. A node-to-node approach is used for
the analysis of stick/slip state. Furthermore, the extent of the contact area is continuously
updated to take into account the nonlinear geometric behavior of the problem. The Newton Raphson method is used to solve the nonlinear system. A comparison with the analytical
results is presented to evaluate the performance and efficiency of the proposed formulation.
The implemented formulation is used for the analysis of experimental tests in order to calculate the necessary stress and strain fields to determine life under fretting conditions. The
results show good agreement with the exact solution when available. The numerical estimate
of the fatigue life is compared with the experimental life of specimens that were subjected to
fretting fatigue conditions until failure.

COMMITTEE MEMBERS:
Presidente - 1722212 - EDER LIMA DE ALBUQUERQUE
Interno - 1646090 - FABIO COMES DE CASTRO
Externo à Instituição - LUCAS SILVEIRA CAMPOS - UFES
Externo à Instituição - SERGIO GUSTAVO FERREIRA CORDEIRO - ITA
Interno - 3375759 - TAYGOARA FELAMINGO DE OLIVEIRA