APPLICATION OF ELECTRIC POTENTIAL METHOD ON MONITORING FATIGUE CRACKING OF AIRCRAFT STRUCTURAL ELEMENTS

摘要

In this paper, the principle of electric potential method for monitoring crack was introduced. On the basis of this method, a set of experiments with the aluminum foils film were carried out for validating its feasibility, and then a typical aircraft structural element-middle-hole LY12-CZ plate specimen was employed here to simulate the process of the fatigue crack propagation of the aircraft structural element. Finally, curves and formulae about the relationship between voltage values and crack length value were obtained from the results of these experiments. From these curves and formulae, we could find that a certain crack only corresponds with a set of certain voltage values, and vice versa. And it is possible to recognize and monitor the fatigue cracking position and crack length on the aircraft structures exactly through the electric potential method.