Data Analysis Methods for Short Rod and Short Bar Fracture Toughness Tests of Metallic Materials

摘要

The behavior of short rod and short bar metallic specimens when measured for plane-strain fracture toughness is described. Such measurements are of increasing interest due to a simplicity of specimen design, small specimen size, automatic creation of a natural precrack without fatigue, and the accuracy and reproducibility of test results. The report describes four basic behavior types and the procedures used for data analysis. Most materials have a relatively smooth crack during testing, but some, including many steels, exhibit a jump behavior which requires a different procedure. Specimen geometry, test procedures, and data analysis methods combine to provide good measurements of the plane-strain fracture toughness even in the presence of macroscopic stresses and limited plasticity during the test. Criteria for judging the validity of test procedures are presented.