Development of P-I Diagrams for Framed PVB-Laminated Glass Windows

This paper investigates isodamage criteria for framed PVB (polyvinyl butyral) laminated glass panels subjected to blast load. Isodamage criteria are presented in the form of pressure-impulse (P-I) diagrams, and a methodology for the generation of the P-I diagrams for laminated glass was developed based on numerical simulation studies and the energy method. Three damage levels were classified in accordance with the conditions identified in standards, namely (1) the glass crack limit, (2) the PVB rupture limit, and (3) overall detachment with a specific velocity after the PVB ruptures. Based on nonlinear finite-element analysis, the governing failure modes of the glass panel in both impulsive and quasi-static regions for each damage level were identified and the corresponding deflection functions were determined. A simplified PVB tensile bar model is proposed to describe the local tensile failure of PVB laminated glass corresponding to Damage Level III under impulsive loading. The pressure and impulse asymptotes of framed PVB-laminated glass for different damage levels were derived using the energy balance principle. The proposed method was validated through comparison with published experimental data and further numerical results. This method can provide a reference for engineering design and hazard estimation of framed PVB-laminated glass against blast loading and can be extended to laminated glazing with other interlayers.