抄録
The work-hardening exponent n more or less shows strain dependence, which is directly obtainable from tensile load-elongation data in the uniform elongation range. The variation in n with strain is monotonic except for during the beginning of deformation and can be simply represented by a linear or parabolic function for most annealed or tempered metal sheets. Supposing that the n-ε relationship remains unchanged after the maximum load, the corresponding constitutive equation is easily determinable. When the load-elongation curve predicted by finite element analysis with the constitutive equation does not agree well with the experimental one, the parameters are optimized by the inverse analysis. Because the number of parameters is sufficient when using two at most, optimization is very easy. The proposed method has been applied to several metal sheets among which the work-hardening behavior differs markedly. The excellent agreement between the analytical and experimental load-elongation curves was obtained for all the materials, and it was verified that this method was simple and effective for estimating the stress-strain relationship in the post-uniform elongation range.
