Issue 35

T. Holušová et alii, Frattura ed Integrità Strutturale, 35 (2016) 242-249; DOI: 10.3221/IGF-ESIS.35.28 244 Figure 2 : Schematic diagram of a modified compact tension test with dimensions in 2D: a) current set-up; b) set-up with eye nuts at the ends of the steel bars. Figure 3 : Attachment of an experimental specimen to a servo-hydraulic test machine. According to the schematic diagram above: a) current set-up - attachment without torsion; b) set-up with eye nuts in the ends of the steel bars. In studied case the cylindrical shape was chosen because such specimens can be conveniently created from drill cores, cylinders usually used for evaluating the age and condition of material taken from existing structures. The MCT test specimen can be prepared as follow: the holes are drilled from the sides of the specimen, perpendicular to the starting notch, so that the steel bars can be allocated and glued inside of the specimen. The values in Tab. 1 show the predicted dimensions of the MCT specimens used for numerical calculations and also for the intended experimental procedure, where: ϕ cs is specimen diameter [mm], W is specimen width, i.e., the distance from the load axis to the opposite side of the specimen [mm], a is notch length measured from the load axis [mm], B is specimen thickness [mm], ϕ sb is the diameter of the steel bars [mm],  is relative notch length [-] and A lig is the area of the ligament [mm 2 ]. Specimen dimensions ϕ cs [mm] W [mm] a [mm] B [mm] ϕ sb [mm]  [-] A lig [mm 2 ] 150 120 36 60 8 0.3 5 040 Table 1 : Used dimensions of the MCT specimens in numerical study. a) b) a) b) Eye nuts at the ends of the steel bars Current grips