Development of thermoplastic constitutive models for refractory ceramics in wide temperature range

Refractory materials play a crucial role in all applications involving the exposition of components to high temperatures and high thermal gradients. For applications in the steel industry, refractory components are mostly manufactured using compounds of ceramic powders binded with resins which are designed to achieve astonishing stability in the severe working conditions, but have relatively short life cycle and are not easily recyclable. Modeling and simulation can greatly enhance the design of these components to maximize material usage and working life, avoiding early disposal. The goal of this work is to provide a new computational framework able to describe the complex behavior of refractories under working conditions, with specific attention to the asymmetric tension-compression behaviour and its evolution in the full range of working temperatures. The model takes into consideration inelastic flow in compression and brittle fracture behaviour in tension by leveraging the continuum-mechanics theory of plasticity and phase-field fracture damage. The model is implemented in the Finite Element open-source platform FEniCS and applied to the analysis of thermal shock conditions of industrial refractory components.