A shallow crack assessment scheme for generalised material behaviour in bending

An engineering J-integral estimation procedure has been developed from data generated using finite element computations. The study has been focused on shallow edge cracked geometries with crack depths up to 10% of the specimen depth and subjected to severe localised plastic deformation under pure bending loading. The material behaviour considered is of a generalised nature—one that consists of a perfectly plastic plateau preceding the work hardening region, which is represented by power law. J-estimation equations were developed from curve-fitting a large number of J versus remote strain curves obtained from finite element analyses. The validity of the proposed scheme was confirmed by comparison with finite element solutions on specimens with fictitious and real material curves. The current work, together with a previously presented scheme for tension loading, hence provides a comprehensive treatment of defect assessment of shallow cracked geometries under severe localised plastic deformation.