Effects of specimen size and crack depth ratio on calibration curves for modified compact tension specimens

摘要

The compact tension (CT) test is frequently used to determine fracture properties of metallicmaterials, such as fracture energy, fracture toughness, crack propagation rate and J-R curves. In thecase of cement based composites, a modified compact tension (MCT) specimen can beadvantageously used due to the negligible stress concentration arising around the pulling dowel pinsduring the test. In this work, finite element calculations are used to determine the calibrations curvesfor the stress intensity factor K, COD, CMOD and CMOD(4), needed for an accurate determinationof the fracture parameters, as a function of the ratio a/W. Nominal diameters are selected accordingto the used core bits between 50 mm and 300 mm.