Volume 19, Issue 3 (May 1991)
Theoretical Comparison of Error in KIc Values Determined by Different Testing Methods of Ceramics
Experimental errors in measuring the values of the different variables included in the formulae for KIc evaluation can affect the accuracy of fracture toughness results. In this work, the effect of error propagation, leading to the final error in the KIc value, is analyzed in terms of type of testing method and specimen geometry.
A review of eight different specimen geometries and procedures for fracture toughness testing of ceramics is given. The analysis was carried out through a FORTRAN 77 program specially developed for this purpose. The computer program takes into account the allowable errors that are associated with each type of recommended experimental procedure or common practice. Results obtained on hot-pressed silicon nitride (HP Si3N4) are presented as an example, but the conclusions can be extended to other engineering ceramics.