TrueStressStrain
True stress and true strain describe material deformation using the instantaneous dimensions of the specimen, rather than the original gauge dimensions. They provide a more accurate description of material behavior at large deformations, common in metals during plastic flow and forming processes. The true stress is defined as the applied force divided by the current cross-sectional area, sigma_t = F / A_i. The true strain is defined as the natural logarithm of the length ratio, epsilon_t = ln(L_i / L_0) = ∫(dL / L).
In comparison, engineering (or nominal) stress and strain use the original cross-sectional area and length: sigma =
Applications include material property characterization, metal forming simulations, and constitutive modeling in finite element analysis. True-stress–true-strain
Measurement considerations involve determining the instantaneous cross-sectional area, which may require imaging techniques or non-contact methods