Experimental Observation and Measurement for Domain Switching Emission Wave and its Average Velocity Emitted from the Near Tip Zone of a Static Crack in PLZT

Abstract

In this paper the strain-birefringence correlation technique (Lines and 1; 2; Scott, Ferroelectr Rev 1:1–129 3) is used to measure the optical birefringence quantities and the corresponding electric and mechanical quantities in a cracked PLZT-8/65/35 to study the electrical creep problem near a static crack tip. Experimental observations reveal that the domain switching emission wave (abbreviated as DSEW) is emitted from the crack tip as the time increases from 0 to 1,500 s. The measured DSEW spreads very slowly and the average speed of the wave is measured to be approximately1.25 μm/s. Although the wave has apparent anisotropic features emitted from the crack tip, the average wave speeds along three different directions from the tip show small differences. After 1,500 s experimental observations reveal that the DSEW occupies almost the whole region under consideration in the specimen. This phenomenon has not been reported in the literature. Some brief discussions are presented.