Glass-polymer laminates designed as safety glazing for automotive and architectural applications demonstrate a rich variety of deformation and failure modes due to the complex stress fields developed on loading and the statistical nature of glass fracture. This complexity in stress development results from the large modulus mismatch between float glass and typical polymers used in safety glazing. In this paper the authors have investigated stress developments and the sequence of glass-ply fracture in model two-ply glass-poly(vinyl butyral) (PVB; Butacite) laminates during loading in biaxial flexure using a circular (upper) punch on three-point (lower) support. The experiment is analyzed using a three-dimensional finite-element model with a viscoelastic constitutive model of plasticized PVB deformation.
