Evaluation of Fracture Toughness (J_IC) Using Single Specimen Fracture Test Augmented by Finite Element Analysis

Fracture toughness is evaluated using the combination of results from a single compact tension fracture test and computationally developed key-curves. The key-curves—a family of load-deflection curves for the test specimen with different length cracks—were developed using the tensile flow properties of the material. By overlaying the experimental test results on these curves the crack length and crack growth during the test can be deduced. The value of J for each crack length is then evaluated from the experimental load-deflection data. The J versus crack extension curve is plotted and J_IC evaluated. The method is applied to the evaluation of the toughness of depleted uranium and is shown to substantially reduce the scatter often observed in the J versus Δa data.