Tensile strength:
What will be its ultimate tensile strength?
Solution
The condition for necking is = n = 0.3077
Hence using this value of, the true stress at necking
= 449.35 (0.3077)^{0.3077}
= 449.35 × 0.696
= 312.67 N/mm^{2}
Hence maximum load, where, Au is the area of cross-section at P_{u}.
Note
0.3077 = ln (128.6144/ A_{u})
∴ 128.6144 / A_{u} = 1.36
or A_{u} = 94.55 mm^{2}
∴
= 312.67 × 94.55 N
= 29.6 kN
The ultimate tensile strength = P_{u} / A_{0} = 29.6 × 103 / 128.6144