A cylindrical metal specimen 15.0 mm (0.59 in.) in diameter and 150 mm (5.9 in.) long is t...

A cylindrical metal specimen 15.0 mm (0.59 in.) in diameter and 150 mm (5.9 in.) long is to be subjected to a tensile stress of 50 MPa (7250 psi); at this stress level, the resulting deformation will be totally elastic.

(a) If the elongation must be less than 0.072 mm (2.83 × 10–3 in.), which of the metals in Table 6.1 are suitable candidates? Why?

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(b) If, in addition, the maximum permissible diameter decrease is 2.3 × 10–3 mm (9.1 × 10–5 in.) when the tensile stress of 50 MPa is applied, which of the metals that satisfy the criterion in part (a) are suitable candidates? Why?

Table 6.1 Room-Temperature Elastic and Shear Moduli and Poisson’s Ratio for Various Metal Alloys

5See, for example, W. F. Riley, L. D. Sturges, and D. H. Morris, Mechanics of Materials, 6th edition, Wiley, Hoboken, NJ, 2006.

6The SI unit for the modulus of elasticity is gigapascal (GPa), where 1 GPa = 109 N/m2 = 103 MPa.