3.22 | Spring 2008 | Graduate

Mechanical Behavior of Materials

Syllabus

Course Meeting Times

Lectures: 2 sessions / week, 1.5 hours / session

Recitations: 1 session / week, 1 hour / session

Overview

Here we will learn about the mechanical behavior of structures and materials, from the continuum description of properties to the atomistic and molecular mechanisms that confer those properties to all materials. We will cover elastic and plastic deformation, creep, fracture and fatigue of materials including crystalline and amorphous metals, semiconductors, ceramics, and (bio)polymers, and will focus on the design and processing of materials from the atomic to the macroscale to achieve desired mechanical behavior. We will cover special topics in mechanical behavior for material systems of your choice, with reference to current research and publications.

Teaching Team

Prof. Krystyn J. Van Vliet
Dr. Jonathan Trenkle

Lectures

Force distributions in structures (review); failure in context
Displacement → strain; Internal force → stress
Tensorial stress and strain; transformations

Elasticity

  • Linear: continuum; isotropic; anisotropic; multiaxial; atomistic basis
  • Nonlinear in crystalline materials: pseudoelasticity
  • Rubber elasticity: latex to DNA
  • Viscoelasticity: elasticity and fluidity

Plasticity

  • Limit of elastic response: uniaxial and multiaxial
  • Mechanisms in crystalline materials: dislocations, twins, and APBs
  • Mechanisms in noncrystalline materials
  • Strengthening via microstructure, environment, and physical size

Creep

  • Time-dependent plasticity
  • Deformation mechanism maps of elastoplasticity

Fracture

  • Evolution of fracture models: ultimate failure
  • Microstructural mechanisms of fracture strengthening

Fatigue

  • Failure below fracture stress: insidious failure
  • Empirical fatigue models
  • Microstructural mechanisms of prolonged fatigue lifetime

Special Topics

Lest you think that mechanical behavior of materials does not impact your intellectual or research interests, you will form small groups (4 people, max) around a common, special topic in mechanical behavior. 10 topics are listed on the wiki (e.g., mechanics of liquid crystals), and we can discuss additional, possible topics. The idea is that you will follow this special topic of significant interest to you throughout the entire class, from elasticity to fatigue failure. Each problem set will contain one problem for only your group (listed on the wiki) which may include readings from recent publications, and you will present a summary of this special topic in a brief lecture to the class at the end of the semester. Choose wisely and have fun!

Textbooks

Required

Courtney. Mechanical Behavior of Materials. 2nd ed. Long Grove, IL: Waveland Press Inc., 2005. ISBN: 9781577664253.

Grading

Breakdown

ACTIVITIES PERCENTAGES
Quiz 1 25%
Quiz 2 25%
Quiz 3 30%
Six problem sets Total 20%

Academic Honesty

We encourage you to work together on problem sets and lab analysis/discussion. However, all work turned in must be your own product, as it stands on the submission due date. What is cheating?

  • Duplication of others’ problem set solutions or quiz responses is cheating.
  • Failure to cite sources of ideas and/or facts in your problem sets and other assignments is cheating.
  • Falsifying excuses for late/missing assignments or lab participation is cheating.
  • Backdating/alteration of submitted documents and false claims that electronic files have been submitted by the due date are cheating.

A student who cheats will receive a formal letter in his/her file at the Office of Student Discipline and may be reported to the Council on Discipline. You do not need to cheat to succeed in this class!

Who is grading?

Prof. Van Vliet will grade the three quizzes noted above. Van Vliet will grade the wiki content related to special topics. A grader (TBA) will grade all problem sets, using solutions provided by Van Vliet and Trenkle. Don’t bug Trenkle about the grading.

Overall Understanding

An “A” in 3.22 means that you have shown you can understand and apply the following quote to make a positive difference with your knowledge of material mechanical behavior:

“Give me matter, and I will construct a world out of it.”

—Immanuel Kant

as quoted by Bedford and Liechti, Mechanics of Materials (2000).

Course Info

As Taught In
Spring 2008
Level
Learning Resource Types
Simulation Videos
Exams with Solutions
Projects
Problem Sets with Solutions