A SHALLOW CRACK ASSESSMENT SCHEME FOR GENERALIZED MATERIAL BEHAVIOR 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 defor mation under pure bending loading. The material behaviour considered i s of a generalised nature-one that consists of a perfectly plastic pla teau preceding the work hardening region, which is represented by powe r law. J-estimation equations were developed from curve-fitting a larg e number of J versus remote strain curves obtained from finite element analyses. The Validity of the proposed scheme was confirmed by compar ison with finite element solutions on specimens with fictitious and re al material curves. The current work, together with a previously prese nted scheme for tension loading, hence provides a comprehensive treatm ent of defect assessment of shallow cracked geometries under severe lo calised plastic deformation. (C) 1997 Elsevier Science Ltd.