Determining fracture mode transition behavior of solid materials using miniature specimens

摘要

A method of determining fracture mode transition behavior (FMTB) of solid materials by using stress field modified miniature specimens. The method is an improvement in the method of determining mechanical behavior information from specimens only so large as to have at least a volume or smallest dimension sufficient to satisfy continuum behavior in all directions. FMTB of the material is determined from the measurements taken during the loading of the specimen resulting in the formation of cracks and/or the further propagation of cracks in the miniature specimen and/or fracture. The specimens are provided with grooves that induce additional stress field modifying stress components in the specimens during the test. These additional stress components result in a desired stress state in the specimens which could not be achieved otherwise. The methods are useful in determining FMTB for the material, when the specimen thickness is smaller than previously thought necessary for valid FMTB determinations.