Influence of the Nonsingular Stress Terms on Small-Scale Supercritical Transformation Toughness

In the present paper we examine the influence of the secondorder term of the asympotic stress solution for mode-I, steady-state, plane-strain, quasi-static crack growth in a supercritically trasforming material. It was found that the second-order term can affect the toughness, not always in a positive way. The second-order term includes the effects of the loading, of the overall geometry, and of the crack length. The findings can be used for the evaluation of the purely material resistance curves of small-scale transforming ceramics, as well as for the toughness predictions of these materials. The results may be useful for unifying different test results, and for a better understanding of the strength-toughness relation.