A finite element investigation of the effect of crack tip constraint on hole growth under mode I and mixed mode loading

In this work, the effect of constraint on hole growth near a notch tip in a ductile material under mode I and mixed mode loading (involving modes I an d II) is investigated. To this end, a 2-D plane strain, modified boundary l ayer formulation is employed in which the mixed mode elastic K-T field is p rescribed as remote boundary conditions. A finite element procedure that ac counts for finite deformations and rotations is used along with an appropri ate version of J(2) flow theory of plasticity with small elastic strains. S everal analyses are carried out corresponding to different values of T-stre ss and remote elastic mode-mixity. The interaction between the notch and ho le is studied by examining the distribution of hydrostatic stress and equiv alent plastic strain in the ligament between the notch tip and the hole, as well as the growth of the hole. The implications of the above results on d uctile-fracture initiation due to micro-void coalescence are discussed. (C) 1998 Elsevier Science Ltd. All rights reserved.