Inspection of ratcheting models for pathological error sensitivity and overparametrization

Accurate analysis of plastic strain accumulation under stress-controlled cyclic loading is vital for numerous engineering applications. Typically, models ratcheting are calibrated against available experimental data. Since actual experiments not exactly accurate, one should check the identification protocols pathological dependencies on errors. In this paper, a step-by-step algorithm presented to estimate sensitivities identified material parameters. As part sensitivity method, new mechanics-based metric in space parameters proposed especially ratcheting-related The errors estimated, based metric. Moreover, relation between error and overparametrization established. This gives rise criterion overparametrization. advantages exposed its plausibility checked by alternative criteria, like consideration correlation matrices validation “unseen” For demonstration purposes, irreversible titanium alloy VT6 (Russian analog Ti-6Al-4V) analysed. Three types phenomenological considered. They Armstrong-Frederick model as well first second Ohno-Wang models. Based real data, rule isotropic hardening greater accuracy simulation. ability determine reliable unreliable demonstrated.