Advances in Development of J-Integral Experimental Estimation, Testing and Standardization

The J-integral is an important concept in the elastic-plastic fracture mechanics, and serves as a critical material parameter to quantify the toughness or resistance of ductile materials against fracture. The relation between the J-integral and crack extension has been widely used as the resistance curve of ductile materials in fracture mechanics design and in structural integrity assessment. Experimental testing and evaluation have played a central role in providing reliable fracture toughness properties to fracture mechanics analysis. Since the J-integral concept was proposed, extensive efforts of investigations have been made to develop its experimental estimation method, testing technique and standardization, as evident in the ASTM E1820 — a commonly used fracture toughness testing standard. In recent years, significant progresses of the J-integral fracture testing and experimental estimation have been achieved, and a part of them was accepted and updated in ASTM E1820. To better understand and use this fracture testing standard, the present paper gives a brief review of historical efforts and recent advances in the development of the J-integral experimental estimation and standard testing.