MATERIALS ENGINEERING CONCEPTS - Materials for Civil and Construction Engineers - page 43

Elastic Modulus, Yield Strength, Tensile Strength,

Material GPa MPa MPa

Copper 110 248 289

Aluminum
alloy 70 255 420

Steel 207 448 551

Brass alloy 101 345 420

1.10 The stress-strain relation shown in Figure P1.10 was obtained dur-
ing the tensile test of an aluminum alloy specimen.

60,000

40,000

20,000

0

0 0.002 0.004 0.006 0.008

Strain, in./in.

FIGURE P1.10

Determine the following:
a. Young's modulus within the linear portion
b. Tangent modulus at a stress of 45,000 psi
c. Yield stress using an offset of 0.002 strain
d. If the yield stress in part c is considered failure stress, what is the
maximum working stress to be applied to this material if a factor
of safety of 1.5 is used?
1.11 A tension test performed on a metal specimen to fracture produced
the stress-strain relationship shown in Figure P1.11. Graphically
determine the following (show units and all work):
a. Modulus of elasticity within the linear portion.
b. Yield stress at an offset strain of 0.002 in./in.
c. Yield stress at an extension strain of 0.005 in/in.
d. Secant modulus at a stress of 62 ksi.
e. Tangent modulus at a stress of 65 ksi.