Extracting Jc Based Upon ɳ Factor; a Challenge for Single Specimen Testing of Elastomers

This study is on the use of J-integral approach for fracture toughness testing of elastomeric materials. At the moment, multiple specimen test method is the most commonly used method for elastomeric materials. However, this test method requires a large number of samples to be tested, and it is costly and time-consuming. Single specimen method has the advantage that there is no need to test many samples but there is a lack of adequate research in this field. The main challenge with this method is how to extract the ɳ factor. Few previous studies for determination of ɳ indicate that it is merely geometry dependent like metals. In this Research, the selected specimen geometry is a double-edge-notched tension (DENT) sample, which is a very popular sample. In contrast to the previous investigations, both our experimental and numerical results show that extracted ɳ values are completely dependent on the material and the loading level along with the geometry. Also, It is shown that the constant ɳ* claimed for the DENT specimen in the literature is not correct and there is a variation of 42% relative to the type of material.