
What are the parameters in this equation?
 e = Engineering Strain
 = Elongation
 L_{o} = Original Length

What does this equation describe?
 s = Engineering Stress
 F = Applied Force
 A_{o} = Original Cross Sectional Area

What equation describes reduction in area due to an axial force, and how does it relate engineering stress to true stress?

What is Hooke's Law for normal stress and for shear stress?

How is True Strain ( ) defined, and how is it related to Engineering Strain (e)?

How is True Strain ( ) related to Area Reduction?

For circular or square crosssections, how is true stress (σ) related to engineering stress (s), engineering strain (e), and Poisson's Ratio ( )?

How is true stress (σ) related to engineering stress (s) and engineering strain (e)?


What is the Modulus of Resilience?
The area under the linear portion of the stressstrain curve.

What is the Modulus of Toughness?
The total area under the stressstrain curve, up to fracture.

How does shear strength compare to yield strength, for both maximum shear stress theory and distortion energy theory?
 (max shear stress theory)
 (distortion energy, von Mises)

How is angle of twist related to Shear Modulus?

 A Proportionality Limit
 B Elastic Limit
 C Yield Point
 D Ultimate Strength
 E Fracture Point
 F Elongation at Failure
 O'Permanent Set

What is the definition of ductility?

What is the definition of hardness?
Hardness is the ability to resist surface deformation.

Identify what is happening at A, B and C in the stages of creep, shown.
 A  Work hardening
 B  Steadystate creep (min. creep rate)
 C  Fracture

Which statement is true for ductile materials?
A. The compressive strength is equal to the tensile strength

Which statement is true for brittle materials?
A. The compressive strength is greater than the tensile strength.

How can the use of engineering stress and strain (rather than true stress and strain) be justified?
 Designs using ductile materials are limited to the elastic region, where engineering and true values differ little.
 The area reduction (needed for true stress) is generally not known. Only the original area is known (needed for engineering stress).

