Evaluation of the delamination performance of polyvinyl-butyral laminated glass by through-cracked tensile tests

Abstract

The interfacial adhesion between the interlayer and glass plays a vital role in determining the safety and post-fracture behavior of PVB-laminated glass. To get a better understanding of the delamination behavior of PVB-laminated glass, a series of through-cracked tensile (TCT) tests were carried out. Influences of different PVB adhesion grades (TROSIFOL® BG R15 and BG R20), loading rates (3 mm/min and 300 mm/min), and interlayer thicknesses (0.76 mm, 1.52 mm, and 2.28 mm) were considered in the tests. Digital image correlation (DIC) technology was adopted to record the delamination process. The delamination length, strain distribution on the PVB interlayer as well as delamination angle, were obtained through DIC analysis. Based on the test results, three typical delamination modes, i.e., unstable delamination, stable delamination, and restricted delamination, were observed. The delamination mode is strongly dependent on the adhesion grade and loading rate. Furthermore, to evaluate the interfacial adhesion, energy release rates were calculated based on an analytical approach. The adhesion grade dominates the delamination performance of the PVB-laminated glass. The delamination length of BG R15-laminated glass is much larger than that of BG R20-laminated glass due to lower interfacial energy release rate and hence exhibits better deformability. With the increase of the loading rate, the energy release rate increases for both BG R15 and BG R20 interlayers. The influence of PVB thickness on the interfacial adhesion was insignificant. For the first time, the delamination angle was identified from DIC results, and the results were used to determine the interfacial fracture mode. The results from this study provide more detailed data on the PVB-glass interfacial adhesion properties and a reference for the post-fracture analysis of PVB-laminated glass.