Material Properties 2

  1. What are the parameters in this equation?
    • e = Engineering Strain
    • chart?chf=bg,s,00000000&cht=tx&chl=%5Cdel&chs=18x30 = Elongation
    • Lo = Original Length
  2. What does this equation describe?
    • s = Engineering Stress
    • F = Applied Force
    • Ao = Original Cross Sectional Area
  3. What equation describes reduction in area due to an axial force, and how does it relate engineering stress to true stress?
    • chart?chf=bg,s,00000000&cht=tx&chl=q%3D%5Cfrac%7B(A_o-A)%7D%7BA_o%7D&chs=174x82
    • chart?chf=bg,s,00000000&cht=tx&chl=%5Csig%3D%5Cfrac%7Bs%7D%7B1-q%7D&chs=124x64
  4. What is Hooke's Law for normal stress and for shear stress?

  5. How is True Strain (chart?chf=bg,s,00000000&cht=tx&chl=%5Ceps&chs=14x20) defined, and how is it related to Engineering Strain (e)?

  6. How is True Strain (chart?chf=bg,s,00000000&cht=tx&chl=%5Ceps&chs=14x20) related to Area Reduction?
  7. For circular or square cross-sections, how is true stress (σ) related to engineering stress (s), engineering strain (e), and Poisson's Ratio (chart?chf=bg,s,00000000&cht=tx&chl=%5Cnu&chs=20x20)?
  8. How is true stress (σ) related to engineering stress (s) and engineering strain (e)?
  9. What is Poisson's Ratio?
    Image Upload 1
  10. What is the Modulus of Resilience?
    The area under the linear portion of the stress-strain curve.Image Upload 2
  11. What is the Modulus of Toughness?
    The total area under the stress-strain curve, up to fracture.Image Upload 3
  12. How does shear strength compare to yield strength, for both maximum shear stress theory and distortion energy theory?
    • chart?chf=bg,s,00000000&cht=tx&chl=S_%7Bys%7D%3D%5Cfrac%7BS_%7Byt%7D%7D%7B2%7D&chs=140x70 (max shear stress theory)
    • chart?chf=bg,s,00000000&cht=tx&chl=S_%7Bys%7D%3D%5Cfrac%7BS_%7Byt%7D%7D%7B%5Csqrt%203%7D&chs=142x90 (distortion energy, von Mises)
  13. How is angle of twist related to Shear Modulus?
    chart?chf=bg,s,00000000&cht=tx&chl=%5Cgam%3D%5Cfrac%7BTL%7D%7BJG%7D&chs=114x68 chart?chf=bg,s,00000000&cht=tx&chl=%3D%5Cfrac%7B%5Ctau%20L%7D%7BrG%7D&chs=78x68
  14. Image Upload 4
    • A -Proportionality Limit
    • B -Elastic Limit
    • C -Yield Point
    • D -Ultimate Strength
    • E -Fracture Point
    • F -Elongation at Failure
    • O'-Permanent Set
  15. What is the definition of ductility?
  16. What is the definition of hardness?
    Hardness is the ability to resist surface deformation.
  17. Identify what is happening at A, B and C in the stages of creep, shown.
    Image Upload 5
    • A - Work hardening
    • B - Steady-state creep (min. creep rate)
    • C - Fracture
  18. Which statement is true for ductile materials?

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

    A. The compressive strength is greater than the tensile strength.
  20. 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).
Card Set
Material Properties 2
Mechanical Professional Engineering Exam Review