AN INCREMENTAL-ANALYSIS OF PLANE-STRAIN FULLY PLASTIC CRACK-GROWTH INSTRAIN-HARDENING MATERIALS UNDER EXTENSION

Analyses of inelastic fracture have mainly followed two directions. On e is crack-tip-field analysis in strain-hardening materials (e.g., the HRR solution). The other is whole field analysis in non-hardening mat erials (e.g., McClintock's slip-line approach). In this paper, a theor etical approach that combines the two directions is presented to accou nt for large crack growth. As an example, plane strain mode I fully pl astic crack growth in a single-edge-cracked-specimen under extension i s analyzed. The incremental analysis based on the deformed configurati on is developed for large crack growth in strain-hardening materials. A kinematically admissible displacement increment field with crack-tip singularity is first constructed in a presumed symmetrical triangular deformation zone extending from the crack tip to the back flank of th e ligament (whole held). Then the size of the deformation zone is dete rmined by minimizing the total force in each incremental step. The str ain histories of all material points in the ligament are traced and a fracture criterion based on the hole growth theory is applied. The com parisons between the present study and the experiments existing in the literature show the validity of the present approach.