标题：THE SPHERICAL INDENTATION APPROACH FOR FRACTURE TOUGHNESS EVALUATION: A STUDY BASED ON THE ENERGY RELEASE RATE
作者：Zhang, Tairui; Wang, Weiqiang; Li, Aiju
作者机构：[Zhang, Tairui; Wang, Weiqiang; Li, Aiju] Shandong Univ, Sch Mech Engn, Jinan 250061, Shandong, Peoples R China.
会议名称：ASME Pressure Vessels and Piping Conference (PVP 2018)
会议日期：JUL 15-20, 2018
来源：PROCEEDINGS OF THE ASME PRESSURE VESSELS AND PIPING CONFERENCE, 2018, VOL 5
摘要：In this study, we investigated the drawbacks of previous studies regarding the evaluation of fracture toughness from spherical indentation tests (SITs). This was achieved by an examination of the material damage mechanism during indentation tests, uniaxial tensile tests, and Mode I/II fracture tests. A new approach based on the energy release rate was proposed in this study to evaluate the fracture toughness of ductile metals. Scanning electron microscope (SEM) observations revealed that the mechanism for material damage during an indentation test was different with the material damage in uniaxial tensile tests and Mode I fracture tests, but similar to that in Mode II fracture tests. Thus, the energy release rate during SITs should be correlated with J(IIC). Compared with previous studies, this new proposed method was more consistent with the actual damage mechanism and did not rely on the specific critical damage values. Experiments on SA508, SA533, 15CrMoR, and S30408 revealed that the maximum error from this energy release rate-based approach was no more than 13% when compared with their conventional counterparts (compact tension tests), and thus can meet the precision requirement of engineering applications.