Practice Problem

A specimen of some metal having a rectangular cross section 10.4 mm x 13.3 mm is pulled in tension with a force of 8040 N, which produces only elastic deformation. Given that the elastic modulus of this metal is 79 GPa, calculate the resulting strain.

Problem 6.03

A specimen of aluminum having a rectangular cross section9.9 mm × 12.6 mm (0.3898 in. × 0.4961 in.) is pulled in tension with 35500 N (7981 lbf) force, producing only elastic deformation. The elastic modulus for aluminum is 69 GPa(or 10 × 106 psi). Calculate the resulting strain.

Problem 6.08

A cylindrical rod of copper (E = 110 GPa, 16 × 106 psi) having a yield strength of 240 MPa (35,000 psi) is to be subjected to a load of 6660 N (1497 lbf). If the length of the rod is 380 mm (14.96 in.), what must be the diameter to allow an elongation of 0.54 mm (0.02126 in.)?

Problem 6.19

A cylindrical specimen of some metal alloy 7.1 mm in diameter is stressed in tension. A force of 9980 N produces an elastic reduction in specimen diameter of 0.0039 mm. Calculate the elastic modulus (in GPa) of this material if its Poisson’s ratio is 0.34.

Problem 6.37

A cylindrical metal specimen having an original diameter of 10.81 mm and gauge length of 51.2 mm is pulled in tension until fracture occurs. The diameter at the point of fracture is 7.79 mm, and the fractured gauge length is 66.6 mm. Calculate the ductility in terms of (a) percent reduction in area (percent RA), and (b) percent elongation (percent EL).

Problem 6.54

(a) A 9.9-mm-diameter Brinell hardness indenter produced an indentation 2.3 mm in diameter in a steel alloy when a load of 1000 kg was used. Compute the HB of this material. (b) What will be the diameter of an indentation to yield a hardness of 280 HB when a 500-kg load is used?