Dynamic Fracture Characteristics of Cyanoacrylate Weakened Planes in Polycarbonate Material

Weakened plane fracture has been an interesting topic for understanding unconventional oil extraction. Thus, the dynamic fracture characteristics of weakened planes are studied experimentally to investigate the failure mechanism when exposed to stress waves at varying angles. A split-Hopkinson pressure bar (SHPB) and digital image correlation (DIC) are used to test a range of cyanoacrylate-weakened plane specimens that are created between the two-polycarbonate sheet. The weakened plane specimens are made with different inclined angles. Theoretically, a crack surface displacement method using various angles, (β), and crack tip opening displacements are shown to identify the dynamic stress intensity factors of opening-mode KI(t), and in-plane shear mode KII(t). The SHPB is dynamically loaded to fracture the specimen while full-field strains are recorded using digital image correlation, and the data is imputed to the crack surface displacement formulas. A fracture envelope containing θ = 15°, 30°, 45°, and 60° angles is created, and the result of mode I, mode II, and mixed-mode (I/II) are discussed, and the major mode of each inclined angle is identified.