Numerical Analysis of Resource Characteristics of Structural Elements under Thermocycling Loading

Abstract

We discuss methodological aspects of assessment of the service life of structures and devices used in new technologies, paying a particular attention to non-stationary thermomechanical loading of “dangerous” zones of the systems under investigation. As result, using the approach of modern mechanics of the degradable continuum, we develop a model describing the associated processes of viscoplastic deformation and damage accumulation and adapted it to description of thermal fatigue. The presented model describes the main effects of inelastic deformation and damage accumulation processes in polycrystalline structural alloys for arbitrary complex deformation trajectories. A combined form of the kinetic equations for damage accumulation in the areas of interaction between low-cycle fatigue and long-term strength has been proposed, which makes it possible to properly describe the nonlinear nature of the damage accumulation.

Keywords

• thermocyclic durability
• continuum damage mechanics
• viscoplasticity
• complex deformations
• fracture