Experimental investigation into the expansion behaviour of thermally tempered laminated glass plates at asymmetric fracture.

The fragments expansion behaviour of thermally tempered glass (TTG) at fracture, can result in the secondary effects that facilitate the fracture or buckling risks of structural glass members. This paper experimentally investigated the fragment morphology and expansion behaviours of thermally tempered laminated glass (LG) plates with different polymeric interlayers and elastic strain energy levels of glass. A computer-vision-based method was adopted for processing stable-state fracture morphology, in order to obtain the fragment density, fracture surface energy and elastic strain energy release at fracture. These parameters were quantitively analysed and compared with those of monolithic glass (MG) plates, identifying the influence of elastic strain energy, intact glass and interlayer. Subsequently, the expansion behaviours were assessed by examining the strain variations on the intact glass and the overall bending deformation. It is found that all specimens exhibit intense strain variations and half sinusoid expansion-induced deformation shapes at asymmetric fracture. Parametric analysis shows that the stiffness disparity between the studied interlayers results in a more than two-fold variation in the maximum in-plane and out-of-plane expansion. In addition, specimens with greater elastic strain energy present higher expansion responses, and the sensitivity of expansion behaviours towards elastic strain energy variations differs across specimens with different configurations. The present study provides insights for further determining the expansion-induced imperfections of structural glass members at post-fracture state. [Display omitted] • The fragments expansion-induced secondary effects in thermally tempered laminated glass were experimentally investigated. • The geometric features of fragments were extracted and analysed through a computer-vision-based method. • The overall bending deformation and strain variations on the intact glass were captured to examine the expansion behaviours. • The influences of interlayer type and glass elastic strain energy level on expansion behaviours were identified. [ABSTRACT FROM AUTHOR]