Influence of the t33-stress on the 3-D stress state around corner cracks in an elastic plate

When an analysis of the 3-D crack behavior in LEFM is performed, usually only the first term of the Williams series expansion, which corresponds to the r-12 singularity, is taken into account. However, it is well known that tij stresses (second order terms) have still influence. Even when the tij stresses are introduced, the only term usually taken into account corresponds to the t11 factor, generally called T-stress. If a correct 3-D description has to be done, the t33 term has also to be considered. In this work, the relevance of the t33 stress term in the analysis of a mode I corner crack is shown in contrast to other approaches that use certain ad hoc parameters, such as the so called Tz-constraint factor proposed by Guo and co-workers. The analysis is carried out for elliptical corner cracks with different aspect ratios, showing that the introduction of the t33 description avoids the approximations inherent to the Tz approach.