Failure assessment diagram methods for strain-based fracture

Stress-based fracture assessment procedures contain conservatism when assessing strain- or displacement-controlled loads in excess of yield. Alternative strain-based methods are discussed in this paper and compared with an existing approach in the R6 defect assessment procedure that allows reduction in conservatism for the case of fixed displacement or rotation loading. Published finite element results for semi-elliptical cracks in plates are re-interpreted as values of J against remote strain and used to assess recent strain-based estimates of J. An assessment procedure based on a strain-based failure assessment diagram is outlined.