A Comprehensive Investigation on Influence Factors of Fracture Toughness Testing Methods in Metallic Materials for Accuracy Improvements

ABSTRACT The accuracy of fracture toughness (FT) obtained using experimental methods can be influenced by factors, such as material properties and specimen geometries, and the extent of inaccuracy depends on the synthetic impact of these factors. Thus, the impact rule of these factors and corresponding underlying reasons require investigation. However, studies in this research field are significantly insufficient and underdeveloped, leaving risks for engineering structures. This study aims to provide a comprehensive investigation of the commonly used FT testing methods in ductile metallic materials for identifying factors that influence the accuracy of obtained FT and then to reveal underlying reasons for the inaccuracy and offer useful recommendations to assist scholars in conducting FT experiments accurately. The literature review and analysis methodology are performed, and the research scope mainly focuses on the three most commonly used testing methods. The results show that some factors can significantly influence the accuracy of tested FT, which may cause safety and cost problems for engineering structures. This study reveals the underlying reasons for FT inaccuracy, summarizes the influence regularity of factors, gives error ranges of each factor, and provides feasible recommendations to improve experimental accuracy, which fills gaps in this research field to significantly reduce the safety and cost risks of practical engineering structures.