Rectifying fracture toughness of oxide glasses by eliminating chronological artifacts

Abstract

This study investigates systematic errors in fracture toughness (K_Ic) evaluation of oxide glasses using the Double Cleavage Drilled Compression (DCDC) method, primarily caused by discrepancies between set and actual frame intervals (SFI/AFI) during high-speed imaging. These timing inaccuracies distort crack growth velocity measurements, compromising K_Ic determination. A dual-validation correction protocol integrating image metadata extraction and independent chronometry was developed to quantify nonlinear AFI-SFI relationships and eliminate temporal artifacts. Experimental validation on soda-lime-silica glasses demonstrated a > 50 % reduction in K_Ic measurement errors, achieving alignment with conventional methods (SEPB, CNB, SCF) and yielding high precision (standard deviation, σ < 0.01 MPa·m^1/2). Further glass-ceramic testing confirmed the method's robustness, showing exceptional consistency (coefficient of variation, CV < 1 %). The refined DCDC protocol enhances reproducibility, simplifies specimen preparation, and establishes a reliable framework for correlating glass composition with intrinsic fracture toughness, advancing the design of next-generation high-toughness glass materials.