Experimental-Theoretical-Numerical Studies on the Fracture in Ceramic Materials by Thermal Shock – T-shock

Because of their favourable properties at high temperature, as well as in corrosive and erosive environments, ceramic materials are finding ever wider applications in industrial and many other fields. Because of their inherent brittleness and combination of other pertinent properties, ceramic materials, however, exhibit poor resistance to catastrophic failure under thermal conditions which generate thermal stresses. Therefore, for the purpose of reliable engineering design, it is important that the variables which control thermal stress failure of brittle ceramics are well understood.

The degradation of the ceramic materials underwent thermal shock can be shown by quenching tests. One can clearly observe that the residual strength of specimens after quenching falls down considerably once a critical quenching temperature is reached. It is commonly accepted that the appearance of macro-cracks is the principal cause of falling down of the residual strength.

Ceramic materials are developed to satisfy a wide industrial and engineering requirement. Even though considerable progress has been made in the elaboration of high-performance ceramics, researches on evaluation and simulation of damage and fracture of ceramics seems to advance still with difficulty, especially in the case of thermal shock loading. In fact, engineers and scientists often need a detailed and precise description of initiation and growth of macro-cracks in the material under thermal shock. Conventional theoretical and numerical tools cannot provide fully satisfactory responses to this exigency. New methodologies have to be developed for this purpose.

In this project, we propose to establish damage models to deal with the damage and fracture in ceramic materials subjected to thermal shock on the basis of a detailed multi-scale analysis and then to implement these models into a finite element code.

To this end, we will combine the competencies of all the partners who participate to the present project, namely:
- The powerful experimental capacity of the Chinese partners, in skill as well as in equipment;
- The long experience in multi-scale modelling of both the Chinese and French partners;
- The leading position in damage and fracture analyses and in related numerical simulations of the French partners.

All these elements guarantee the formation of an outstanding research team and high-level research quality of the present project.