Mode-I fracture analysis of micro-scale high-temperature superconductors via the double cantilever beam model and gradient elasticity theory.

In this paper, fracture behavior of a micro-scale double cantilever beam (DCB) made of superconducting materials is investigated based on the strain gradient theory. Both zero-field cooling (ZFC) and field cooling (FC) magnetization processes are considered. The closed-form solutions of the energy release rates and stress intensity factors are obtained. For ZFC process, superconducting materials are easy to damage during the process of reducing magnetic field rather than increasing magnetic field. For FC process, applied magnetic field will impede superconductors to damage. Moreover, the normalized energy release rate predicted by classical beam theory is larger than that predicted by strain gradient theory. As the characteristic length increases, the normalized energy release rate decreases. The present model may be useful for designing experiments to test the fracture toughness of micro-scale high-temperature superconductors. [ABSTRACT FROM AUTHOR]