Shear modulus of ionomer interlayer: Effects of time, temperature and strain rate

Abstract

The transparent ionomer material SentryGlas® or SG for short is widely used as interlayers in laminated glass and is also a potential adhesive in laminated connection. The material’s shear modulus is of practical interest before glass breakage because it allows a shear transfer between glass components. Due to the viscoelasticity behaviour of the material, its modulus is significantly dependent on the working conditions. This work investigates the effects of temperature, time, and strain rate on SG’s shear small-strain modulus from the point of practical application. The shear property at room temperature is obtained from the results of shear tests. Based on the viscoelastic theory, the time and temperature dependence within the actual application range is quantitively determined from DMA measurements. The glass transition temperature associated with modulus decline is then recalibrated. The effect of strain rate is also qualitatively measured. Finally, the time-temperature dependent equations of shear modulus are applied to numerical simulation of a long-term loading test on framed ionomer interlayer laminated glass.