Theoretical study on extension of crack tip plastic zone by remote simple tensile considering crack interaction

Abstract

In many cases, crack coalescence could be due to the contact of crack tip plastic zone of two cracks. Thus, it is an important work to study the extension of crack tip plastic zone considering interaction of two cracks. Based on the basic theories of famous Kachanov method and with the widely used Mises yield criterion, the extension of crack tip plastic zone by far-field simple tensile considering interaction of two collinear unequal cracks has been researched. And the theoretical equations of the crack tip plastic zone radius under both plane stress and plane strain conditions have been derived. At last, the influence of some factors (main crack length, secondary crack length, crack space and crack angle) on the extension of crack tip plastic zone have been analyzed comprehensively. The results show that, as the increase of the main crack length, the crack tip plastic zone size of the main crack decreases, and while that of the secondary crack increases. As the secondary crack length increases, the crack tip plastic zone size for main crack increases, and that for secondary crack decreases. As the crack space decreases, the crack tip plastic zone size for two cracks develops very quickly, and the cracks extend quickly. Moreover, as the crack angle increases, the effect of crack space on the crack tip plastic zone size decreases.