Fatigue crack growth in disordered media under ciclic load.

Author(s)

Maycon de Sousa Araújo

• Document type: Doctoral Thesis
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Instituto de Física (IF/SBI)
• Defense date: 2016-08-12

Examining board members

Andre de Pinho Vieira; Roberto Fernandes Silva Andrade; Masayuki Oka Hase; Claudio Lucas Nunes de Oliveira; Carmen Pimentel Cintra do Prado

• Advisor: Andre de Pinho Vieira

Abstract

In this work we consider a statistical model in a micrometric scale of interactions between the components of the system which intends to describe the failure of materials subjected to cyclic-load fatigue. Although quite simple, this model is able to reproduce an important experimental result widespread among engineers and experts, known as Paris law, which states that the growth rate of a crack at subcritical load is proportional to a power of the change in its stress-intensity factor and it is largely used in engineering practice. We are particularly interested to study the introduction of disorder in some parameters of the material investigating the modifications caused by this kind of approach in the statistical properties of the model. Our main results will be obtained numerically assuming an effective-field like approximation which neglects the correlation between the different cracks emerging throughout the system during the breaking process. Numerical simulations of the model are also performed in order to describe more general situations of propagation where the effects of crack self-healing can play an important role in the material strength. (AU)

• FAPESP's process: 11/23256-5 - Fatigue crack growth in disordered media
• Grantee: Maycon de Sousa Araújo
• Support Opportunities: Scholarships in Brazil - Doctorate