Analysis of Glass/Polyvinyl Butyral Laminates Subjected to Uniform Pressure

Complex stress fields develop during the loading of glass/polymer laminates used as architectural safety glazing due to: (1) large glass/polymer modulus mismatch (Eglass/Epolymer ∼ 103–105), (2) polymer viscoelasticity, and (3) nonlinear, large deflection behavior encountered in commercial scale glazing. We present a model for stress analysis of such laminates that consists of a three-dimensional finite-element model incorporating polymer viscoelasticity and large deformations. The model has been applied to study quasi-static deformation of a square, simply supported, glass/polyvinyl butyral/glass laminate in response to uniform pressure loading. One of the major findings is that stress development may fall outside the so-called “monolithic” limit, for two well-bonded pieces of glass, and the “layered” limit, for two freely sliding plates. One reason is because deformation of large plates prior to glass first cracking includes considerable membrane stresses and the monolithic and layered limits are derive...