On the bending of architectural laminated glass

As a result of its numerous environmental qualities, laminated safety glass is being used to an increasing extent in the field of architectural glazing. Its use in the manufacture of aircraft and automobile windscreens is well established, and the impact resistance of such laminates has been extensively studied. However, little work appears to have been done on the response of architectural laminated glass to normal structural loading. In this context, an architectural laminate is defined as comprising two glass layers of arbitrary thickness together with an adhesive plastic interlayer.The aim of the present work is to provide an insight into the fundamental behaviour of architectural laminated glass in bending. To this end, theoretical and experimental studies have been made concerning the action of laminated glass beams in four-point bending. Closed-form expressions are derived for the interfacial shear traction and central deflexion, and relevant numerical values are given. Experimental results are also presented; these relate to a series of tests on small laminated glass beams subjected to both transient and sustained loading at various ambient temperatures.In general, the degree of coupling between the two glass layers is shown to be chiefly dependent upon the shear modulus of the interlayer, which in turn is found to be a function of both the ambient temperature and the duration of loading; in this connexion, basic data are given on interlayer shear stiffness which can be utilized in subsequent structural analyses of architectural laminates.