MSE420 : Mechanical Behavior of Materials

Macroscopic and microscopic aspects of deformation and fracture. Plasticity, general continum approach. Microscopic hardening mechanisms. Rate and temperature dependent deformation. Deformation and fracture mechanism maps. Fracture mechanics. Fatigue behavior.

Cognizant Faculty: Allison, Jones, Thouless

Course Topics:

  1. Stress and strain: tensor nature, general transformation of axes, circles, true vs. engineering stress and strain.
  2. Elasticity: 3-dimensional nature of Hooke's laws, inclusion of thermal expansion in treatment of elastic problems.
  3. Plasticity: Formulation of yield criteria, corresponding flow rules, effective stress and strain functions.
  4. Effects of work hardening, strain-rate and temperature on stress-strain behavior. Mathematical approximations.
  5. Mechanics & crystallography of slip and twinning. Application of a generallized Schmid's law to predicting stress for slip and resulting strains.
  6. Dislocation theory.
  7. Fracture mechanics.
  8. Fatigue and creep
  9. The effect of structure on strength, ductility and toughness.
  10. Different behaviors of metals, ceramics and polymers. Composites.
  11. Introduction of mechanical working and residual stresses.

Course Objectives:

  1. To teach students to recognize common boundary conditions and appropriate constitutive relations to solve numerical problems stress and strain.
  2. To teach an understanding of how deformation and fracture occur and how structure affects mechanical behavior.

Course Outcomes:

  1. Be able to calculate uniform elongation & tensile strength from various approximations to the true stress strain behavior.
  2. To be able to quantitatively assess the effects of imperfections on the elongations in strain-hardening and strain-rate sensitive materials.
  3. To be able to use the stereograp[hic projection to slip systems and predict lattice rotations caused by slip.
  4. To be able to use yield criteria & flow rules to relate the stress state to the plastic strains.
  5. To understand the role of microstructure and defects in determining mechanical behavior.
  6. To be able to use fracture mechanics to determine whether a material will fracture before yielding.

Assessment Tools:

  1. 30 home assignments
  2. 2 mid term exams
  3. final exam