The Method to Obtain J<sub>R</sub>- Curve by Continuous Ball Indentation Method

Abstract

JR-curve is one of an important index to characterize the fracture properties of metal materials. It is usually determined by multi-sample unloading method and single-sample unloading compliance method recommended by standard methods; In consideration of the similarity between the continuous ball indentation method and the single-sample unloading compliance method, The JR-curve is obtained by using the empirical correlation between effective elastic modulus ED of the continuous ball indentation and the unloading compliance C for single simple in this article. The calculation conducted by the correlation formula of the extension length of crack with unloading compliance C. However, results indicate that the fracture toughness J0.05 obtained by empirical correlation of load-depth curve of continuous spherical indentation is still quite different from those given by the standard test.