Fracture and fatigue of piezoceramics under mechanical and electrical loads

Abstract

Piezoelectric materials have found a wide range of applications in smart structures because of their high modulus and strong electro–mechanical coupling. The use of piezoceramics as actuators in smart structures demands that these materials perform under increasingly high electric and mechanical loads. Durability and reliability of actuators become important issues. Therefore, fracture (failure under monotonic mechanical and electrical loads) and fatigue (failure under cyclic loads) behavior of piezoceramics must be understood and accurately modeled. Fatigue tests using compact tension specimen under various combinations of electric and mechanical load were conducted to develop a crack growth model. Experimental results indicated that crack growth could be significantly influenced by electric fields. However, it could not be accounted for by the apparent stress intensity factor alone.