R-Curve Modelling with Constraint Effect

A method for constructing R-curve has been developed. Three constraint theories (T-stress, Q-stress and A2) have been used to construct constraint-dependent R-curves. The predicted R-curves have been compared against test results taken from published literature. A comparison of the predicted constraint based R-curves against the testing result was given. It is shown that the developed method provides an efficient approach to obtain R-curves under low constraint and can potentially be used for engineering critical assessment (ECA) in various industry sectors