Fracture Mechanics

Mestrado em Engenharia Mecânica - Projecto e Produção Mecânica
6 ECTS; 1º Ano, 2º Semestre, 22,50 T + 22,50 TP + 3,50 OT

Lecturer

Prerequisites
Not applicable

Objectives
On completion of this course students should be able to solve fracture mechanics problems on mechanical design of parts and structural components and develop skills that will enable them to analyse sizing criteria.

Program
Introduction:
Failure modes. Fracture control.
Linear elastic fracture mechanics:
Strain Energy. Stress intensity factor, plain stress and plain strain. Influence on fracture behaviour, curve R
concept. Mechanical tests, applicability domain Elastic-Plastic Fracture Mechanics.
Concept of the integral J and CTOD. Empirical curve in mechanical design. Tests limitations and applicability
domain.
Fatigue:
Initiate propagation. High number of fatigue cycles and oligocyclic fatigue. Curves SN, effect of average stress,
diagram of Goodman, Palgrem-Miner rule. Factors with influence on fatigue behaviour- Methods of improving
behaviour fatigue. Paris law.
Creep:
Factors that influence the creep behaviour. Types of tests.
Forecast of life under creep. Orr-Sherby-Dorn parameter. Larsson-Miller parameter. Accelerated creep tests.
Fitness for service concept
Fitness for service ? FfS". Control of the fracture. Diagram of fault assessment, FAD. Fatigue.

Evaluation Methodology
Practical assignment: written report (60%) + oral presentation (40%).

Bibliography
- Branco, C. (1985). MECÂNICA DOS MATERIAIS. : Fundação Calouste Gulbenkian
- Wulpi, D. (1999). UNDERSTANDING HOW COMPONENTS FAIL. : ASM
- Morozov, N. (2000). DYNAMICS OF FRACTURE. : Springer

Method of interaction
Conventional lectures and expository lessons. Theoretical/practical lessons involving case study discussions.

Software used in class
SolidWorks, Office (Word, Excel, PowerPoint, etc.), Matlab.