Page 176 - Mechanical Behavior of Materials

Problems and Questions 177

DIETER, G. E., Jr. 1986. Mechanical Metallurgy, 3d ed., McGraw-Hill, New York.
GAUTHIER, M. M., vol. chair. 1995. Engineered Materials Handbook, Desk Edition, ASM International,
Materials Park, OH.
HILL, R. 1998. The Mathematical Theory of Plasticity, Oxford University Press, Oxford, UK.
KUHN,H., andD. MEDLIN, eds. 2000. ASM Handbook: Vol. 8, Mechanical Testing and Evaluation, ASM
International, Materials Park, OH.
MARSHALL, E.R., andM.C. SHAW. 1952. “The Determination of Flow Stress From a Tensile Specimen,”
Trans. of the Am. Soc. for Metals, vol. 44, pp. 705–725.
NADAI, A. 1950. Theory of Flow and Fracture of Solids, 2nd ed., McGraw-Hill, New York.
RICHARDS, C. W. 1961. Engineering Materials Science, Wadsworth, Belmont, CA.

(b) Sources of Materials Properties and Databases
BAUCCIO, M. L., ed. 1993. ASM Metals Reference Book, 3d ed., ASM International, Materials Park, OH.
CES. 2009. CES Selector 2009, database of materials and processes, Granta Design Ltd, Cambridge, UK. (See
http://www.grantadesign.com.)
CINDAS. 2010. Aerospace Structural Metals Database (ASMD), CINDAS LLC, West Lafayette, IN. (See
https://cindasdata.com.)
HOLT,J.M., H. MINDLIN,and C. Y. HO, eds. 1996. Structural Alloys Handbook, CINDAS LLC, West
Lafayette, IN. (See https://cindasdata.com.)
MMPDS. 2010. Metallic Materials Properties Development and Standardization Handbook, MMPDS-05,
U.S. Federal Aviation Administration; distributed by Battelle Memorial Institute, Columbus, OH.
(See http://projects.battelle.org/mmpds; replaces MIL-HDBK-5.)

PROBLEMS AND QUESTIONS

Section 4.3 1
4.1 Define the following concepts in your own words: (a) stiffness, (b) strength, (c) ductility,
(d) yielding, (e) toughness, and (f) strain hardening.
4.2 Define the following adjectives that might be used to describe the behavior of a material:
(a) brittle, (b) ductile, (c) tough, (d) stiff, and (e) strong.
4.3 The offset yield stress and the proportional limit stress are both used to characterize the
beginning of nonlinear behavior in a tension test. Why is the offset method generally
preferable? Can you think of any disadvantages of the offset method?
4.4 Force and length change data are given in Table P4.4 for the initial portion of a tension test
on AISI 4140 steel tempered at 538 C (1000 F). The diameter before testing was 10 mm, and
◦
◦
the gage length L i for the length change measurement was 50 mm.
(a) Calculate corresponding values of engineering stress and strain and display these values
on a stress–strain plot. (Your graph should agree with Fig. P4.5.)
(b) Determine the yield strength for a plastic strain offset of 0.002, that is, 0.2%.
(c) What tensile load is required to cause yielding in a bar of the same material but with
a diameter of 25 mm? How does this value compare with the load at yielding in the
10 mm diameter test specimen? Why do the two values differ?

1
Numerical values given in tables are representative actual data from a large number of samples recorded in each test.