Capabilities of a New Specimen Type for Determining the Static Fracture Toughness

The diversity of modern structural glasses is extremely broad, and their mechanical properties vary significantly. In this work, original specimen geometry is proposed for determining the fracture toughness parameters of glass under quasi-static loading conditions. A key feature of the developed configuration is the presence of a stabilization zone, which ensures crack propagation in a given direction. The specimen shape is justified by the results of a numerical simulation of fracture processes in brittle solids. The proposed geometry is characterized by reduced sensitivity to the loading device stiffness and promotes the straight-line propagation of the crack. Specimen fabrication is straightforward and does not require specialized equipment, allowing mechanical testing to be performed using standard tensile testing machines. The developed configuration ensures stable regimes of crack deceleration and complete arrest. The crack tip formed at this stage acquires a natural configuration, and the geometric characteristics of the initial notch do not have a critical influence on the measurement results. The capabilities of the specimen are demonstrated through both numerical and physical experiments in comparison with the classic compact tension (CT) specimen. Physical testing of glass specimens allowed for obtaining the relationship between the crack velocity and the stress intensity factor within a velocity range from 10−6 to 10−2 m/s.