Miniature C(T) Specimens—Pinhole Eccentricity and the Effect of Crack Opening Displacement Measurement Location

Abstract

This paper focuses on the quality criteria for miniature compact tension (C(T)) specimens. The continuously diminishing volume of reference materials for fracture toughness surveillance testing encourages research on the usability of miniature-sized test specimens, and consequently, it is of great interest in the nuclear power plant field. Sufficient quality criteria and applicability are investigated experimentally and numerically by varying the pinhole locations to investigate the importance of the eccentricity of pinholes and its effect on measurement results. Additionally, the effect of measuring the crack opening displacement (CMOD) from the load line versus the front face and the effect of side grooving are studied with experimental arrangements. The results show that neither the eccentricity of pinholes within the studied offset values nor the location of the CMOD gauge imposes limits on the applicability of miniature C(T) specimens. With eccentric pinholes or any CMOD gauge placement, the fracture toughness results are valid.