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· The same data represented as
true
stress vs. true
strain is shown together with the three regions of deformation.
· In the linear elastic region Hooke's
law
applies:
σ = Eε.
· In
the region of uniform plastic deformation, sample volume is conserved:
Α0L0
= A1L1 .and a power law
links stress and strain : σ
= K εn , where
K = Strength Coefficient n = Strain Hardening Exponent.
· Once a neck
forms, additional plastic deformation is
restricted to the neck region and true strain varies linearly with true stress:
σ = B ε
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