The acoustic measurement of stress intensity factors

Abstract

The maximum stress intensity factor of a surface crack has been inferred by measuring the reflection coefficient of a Rayleigh wave incident to the crack. An acoustic surface wave wedge transducer was used to excite the incident wave and to measure the reflected-wave amplitude. The fracture stress of Pyrex glass specimens containing the acoustically measured cracks was determined in biaxial flexure. The values of the fracture stress predicted from acoustic data were found to be in excellent agreement with the measured values, with less than a 15% error.

Application of the Reciprocity Theorem to Nondestructive Evaluation

“…Substitution of Eqs. (13)- (16) in Eq. (12) then leads to the result where the changes in the Lam6 constants and the density are Ah, Ap, and Ap, respectively, and…”

Calculation and Measurement of Scattering Coefficients for Surface-Breaking Cracks Sonified by a Focused Array

“…By taking a cut through the volume V , the enclosing surface S can be broken up into S = Se + Sil + Si2 + SF, (9) where $1 and Si2 are internal surfaces (Fig. 4).…”

“…Other examples of the measurement of scattering coefficients of surface-breaking cracks can be found in papers by Resch et al [9] and by Cheng and Resch [lo].…”