Assessment of extreme thermo-mechanical states of engineering systems under operating loading conditions

The paper presents basic approaches to assessment of strength, service life, and survivability of structural components of technical systems subjected to various types of operating loading regimes. These include: (i) thermo-mechanical loading regimes of normal operation inducing the states of stress and strain that can be considered using traditional stress-based methods and criteria; (ii) extreme design basis loading regimes related to design basis emergency situations that require a transition to design according to strain-based fracture criteria with accounting for temperature, force and frequency factors, and (iii) loading regimes induced by beyond design basis (accident and catastrophic) situations that should be analyzed using equations and criteria of nonlinear deformation mechanics in its most complex thermally coupled formulation.