Boundary Condition Effects on Failure of Tempered Glass Subject to Wind-borne Debris Impact and Quantification Model for Fragment Distribution

This study addresses critical safety concerns in wind-resistant design of building envelope systems, aiming to quantify secondary fragmentation effects and potential risks from tempered glass breakage under wind-borne debris impact. Through systematically designed hybrid orthogonal impact tests, it comprehensively investigates the influence of key parameters—including impact type, velocity, angle, boundary conditions, glass thickness, and dimensions—on failure modes and fragment mass distribution. Range analysis and variance decomposition of the experimental matrix quantitatively reveal the sensitivity weights of each parameter on glass fracture characteristics, impactor velocity attenuation rate, and fragment mass distribution. A dimensionless functional framework characterizing fragment mass distribution was established using the principle of dimensional homogeneity and Buckingham's Π theorem. Parameter values for the semi-empirical predictive formula were determined via an orthogonal distance regression iterative algorithm, verifying the formula's physical significance and predictive reliability. Results demonstrate: boundary conditions dominantly control glass fracture extent and fragment dispersion (exposed framing support yielding minimal fragment mass - optimal solution); structural glazing support exhibits maximum kinetic energy attenuation yet moderate fragment quantities; point fixing induces complete fragmentation (high-risk scenario); impact angle, glass dimensions, and velocity also exert significant influences. The developed formula accurately characterizes tempered glass fracture patterns, with parameters for exposed framing and structural glazing supports both falling within the order of 10⁰, enabling their combination into a unified framed-type support system model, thereby providing crucial theoretical foundations for wind-resistant design of building envelopes.