Experimental study on the interface fracture toughness of PVB (polyvinyl butyral)/glass at high strain rates

Abstract

Abstract This paper presents the experimental results of high-speed tests using PVB sheets and PVB laminated glass. PVB showed a non-linear visco-elastic property in the low-speed tests. The non-linear visco-elastic property could be described using a simple spring-dashpot model including a non-linear spring. The visco-elastic parameters were determined by comparing the experimentally obtained stress-strain curves to the simulated model in which the various visco-elastic parameters are used. The strain-stress curves of PVB under high strain rates are elasto-plastic and those under the low strain rates are non-linear visco-elastic. The phenomenon can be explained from the phase transition from rubbery phase to glassy phase. Considering the results of PVB tensile tests, a simple fracture-mechanical model of PVB laminated glass was formulated to determine energy release rate G. Fracture toughness G C of the PVB laminated glass specimens were calculated from both the experimental results and the energy release rate. Potential energy U C was defined and also compared to the fracture toughness. Nevertheless, the critical loads increase with respect to the increase of tensile speed; potential energy and the fracture toughness remain the same order in all of the chosen tensile speeds.