ABSTRACT
The maximum load size effect is analysed with the help of the R−Δa curve approach. To this end the concept of equivalent elastic crack is reviewed and it is shown that the R−Δa curve approach is a special case of this equivalence. The analysis includes positive, negative and uncracked geometries. The concepts of nominal stress intensity factor and of intrinsic size are generalized to get consistent results for the asymptotic behaviour up to first order for any geometry and to avoid negativeness of the objective size. Practical examples of these three geometries are included, where the simple predictions based on the equivalent elastic crack are compared with the numerical computations of more involved cohesive cracks.
