Cryogenic static fatigue of cracked piezoelectric ceramics in three-point bending under electric fields

This paper studies analytically and experimentally the cryogenic static fatigue behavior of cracked piezoelectric ceramics under electric fields. The crack was created normal to the poling direction. Static fatigue tests were carried out in three-point bending with the single-edge precracked-beam specimens at room temperature and liquid nitrogen temperature (77 K), and times-to-failure under different mechanical loads and electric fields were obtained. Plane strain finite element analysis using temperature-dependent material properties of piezoelectric ceramics was also performed, and the energy release rate for the permeable crack model was calculated. The effects of electric field and temperature on the energy release rate versus lifetime curve are discussed.