Predicted Mechanical Behavior of High-T sub c Superconducting Ceramic Films.

Mechanical strength and structural integrity of high-T sub c superconductor may play a decisive role when a superconducting material is used for practical purposes. In this analysis we address the left part of the strength condition "actual stress (strain) = allowable stress (strain)", and suggest a simple and easy-to-use analytical model for the evaluation of the elastic thermally induced stresses in an elongated superconducting ceramic film on a thick substrate. These stresses include normal stresses acting in the film itself and responsible for its strength, as well as interfacial (shearing and peeling) stresses responsible for the integrity of the film-substrate composite and the strength of the intermediate material, if any.