Experimental investigation of the effect of crack-arrest techniques on the fracture behavior of ducti̇le materials

In this thesis, the effects of crack arrest mechanisms on the fracture behavior of ductile materials were experimentally investigated. Structural steel S235JR was used, and three different specimen types were prepared: reference specimens without crack arrest holes, specimens with a single crack arrest hole, and specimens with double crack arrest holes. The specimens were subjected to Mode I, Mode II, Mode III, and mixed-mode loading conditions using a specially designed fixture validated through finite element analysis. During the experiments, load–displacement curves were recorded, maximum load capacities were determined, and crack propagation paths were observed. The results showed that fractures in specimens without crack arrest holes occurred suddenly and exhibited brittle characteristics, while the single-hole configuration provided limited delay in crack propagation with effectiveness varying depending on loading scenarios. In the double-hole configuration, crack propagation slowed significantly, maximum fracture load increased, and ductile behavior was enhanced. The experimental findings were compared with existing literature and found to be consistent with current models. This study systematically and comprehensively demonstrates the effectiveness of crack arrest mechanisms in ductile materials and provides valuable design data for engineering applications.