1. The problem statement, all variables and given/known data The strain hardening behavior of an annealed, low‐carbon steel is σ = 100,000ε0.2 If a bar of this material is initially cold worked 20%, followed by additional cold work of 30%, determine the probable yield strength of the final bar. 2. Relevant equations σ=κεη At ultimate strength η=ε (Dont think this is applicable here though?) 3. The attempt at a solution σ=100000(0.5)0.2 = 87055 psi Im not sure what to do with the percentages of cold work given. Can I use it as strain to find the yield strength at 50% cold work? Does the value of η need to be used as % cold work, or does σ = 100,000 ε0.2 represent a funtion of the yield strength? Another attempt I don't think that the % cold work is additive, so am I wrong to assume 50% cold work has taken place? If 30% CW is with respect to the original 20%, then A1/A0 = 0.2 A2/A1 = 0.3 A2/A0 = 0.26 so would σ=100000(.26)0.2 be correct?