Models for process compensated resonant testing (PCRT) of silicon nitride balls.

The paper presents recent progress to model process compensated resonant testing (PCRT) for silicon nitride balls. An analytical model was developed that accurately describes the series of surface acoustic wave (SAW) and intermediate Whispering Gallery (WG) modes. A finite element method model of an elastic sphere was also developed to study the effect of surface flaws on the modal response. Using the numerical model, it was shown that the higher frequency SAW modes will degenerate in most cases as shifts lower in frequency with increasing crack dimensions. [ABSTRACT FROM AUTHOR]