A continuum damage mechanics model for ductile fracture

Continuum damage mechanics theory together with large deformation elastic-p lastic finite element analysis has been used to predict crack growth initia tion in ductile materials. The damage growth law is based on experimental o bservations reported in the literature. A local crack growth initiation cri terion is proposed. The criterion makes use of the critical damage as the c ontinuum parameter and the average austenite grain size as the characterist ic length. To test the validity of this criterion: experiments have been co nducted on standard specimens and have also been simulated numerically. The proposed criterion has been used to predict the values of the critical loa d at crack growth initiation and the fracture toughness. The numerically pr edicted values compare favourably with the experimental values. (C) 2000 El sevier Science Ltd. All rights reserved.