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2021 Faculty Courses School of Engineering Undergraduate major in Mechanical Engineering

Strength and Fracture of Materials (Mechanical Engineering)

Academic unit or major
Undergraduate major in Mechanical Engineering
Instructor(s)
Akira Todoroki / Yoshihiro Mizutani / Chiaki Sato
Class Format
Lecture
Media-enhanced courses
-
Day of week/Period
(Classrooms)
1-4 Fri (I121)
Class
-
Course Code
MEC.C331
Number of credits
200
Course offered
2021
Offered quarter
2Q
Syllabus updated
Jul 10, 2025
Language
Japanese

Syllabus

Course overview and goals

Based on the fundamentals of mechanics learned in Mechanics of Materials and Elastoplastic Mechanics, the instructor will teach the points listed below.
1.Introduction of various failure accidents
2. Fundamentals of linear fracture mechanics
3. Fracture toughness
4. Fatigue,Fatigue crack initiation, Fatigue crack propagation
5. Non-destructive inspection
6. Basic concept of design of strength

Course description and aims

By the end of this course, students will be able to:
1. Understand the dangerous pointsof design based on the examples of failure accidents.
2. Understand the principle of energy release rate.
3. Understand the principle of linear fracture mechanics.
4. Understand the fundamentals of strength, fatigue, design of strength.
5. Select appropriate non-destructive inspection method.
6. Design the strength appropriately to avoid fracture accidents.

failure and fracture of materials, and related mechanics.
2) Understand the fundamentals on the basic characteristics of material strength, fatigue life, and strength design.
3) Carried out strength design of machinery or structures.
4) Identify problems when maintenance troubles occur.

Keywords

Failure accident, Crack, Energy release rate, Stress intensity factor, Fracture toughness, R-curve, Fatigue, Non-Destructive Inspection, Fracture control design

Competencies

  • Specialist skills
  • Intercultural skills
  • Communication skills
  • Critical thinking skills
  • Practical and/or problem-solving skills

Class flow

In the first half students will gain an understanding of basic properties of material strength, as well as the fundamentals of fracture mechanics. In the second half they will learn about applications. Homework will be assigned in some classes for students to deepen their understanding. Please carefully read the learning goals for each class, and prepare and review diligently.

Course schedule/Objectives

Course schedule Objectives
Class 1

History of accidents caused by the fracture of materials and the role of this course

Understand the historical aspects on and percept from accidents caused by fracture of materials.

Class 2

Failure of materials

Understand the types and characteristics of materials.

Class 3

Energy release rates

Understand fracture mechanics in terms of energy balance and the Griffith's theory.

Class 4

The stress field and stress intensity factor near a crack tip

Understand the theory of elasticity of crack tip

Class 5

Stress intensity factor

Understating of stress intensity factors.

Class 6

Examples of stress intensity factors and principle of superposition

Understand the examples of stress intensity factors and principle of superposition.

Class 7

Relationship between energy release rate and stress intensity factor

Understand the principle of stress intensity factor though energy balance theory .

Class 8

Plastic deformation at the crack tip

Understand the plastic deformation at the crack tip.

Class 9

Crack tip opening displacement and fracture toughness

Understand the crack opening displacement fracture toughness.

Class 10

Stable crack growth, R-Curve, Plain strain fracture toughness, Fracture appearance transition temperature, Dynamic fracture

Understanding of Stable crack growth, R-Curve, Plain strain fracture toughness, Fracture appearance transition temperature, Dynamic fracture

Class 11

The mechanism of fatigue crack initiation and propagation; time dependent fracture

Understand crack initiation, velocity, threshold, the mechanism of crack propagation crack ; time dependent fracture opening displacements for fatigue cracks

Class 12

Design of fracture control

Understanding of the basic theory of fracture control and feasibility studies

Class 13

Non-destructive inspection

Introduction and understanding of non-destructive inspection.

Class 14

Exercise

Study advice (preparation and review)

To enhance effective learning, students are encouraged to spend approximately 100 minutes preparing for class and another 100 minutes reviewing class content afterwards (including assignments) for each class.
They should do so by referring to textbooks and other course material.

Textbook(s)

Hideo Kobayashi, Fracture Mechanics (ISBN 978-4-320-08100-0), Kyoritsu Shuppan Co., Ltd.

Reference books, course materials, etc.

Strength and Fracture of Materials (ISBN 4-901381-26-1), The Society of Materials Science, Japan.

Evaluation methods and criteria

Graded with the results of several exercises

Related courses

  • Mechanics of materials
  • Elastoplastic mechanics

Prerequisites

It is preferable that all the students have enough knowledge on mechanics of materials and elastoplastic mechanics.