Effects of fixing point positions on thermal response of four point-supported glass façades

Different fixing forms of four point-supported glass façades are extensively used to satisfy the aesthetic requirement of modern buildings. While it may easily break and fall out when subjected to a fire, which could significantly affect compartment fire dynamics by creating a new opening for air to enter. In this work, sixteen cases with different fixing positions are designed to investigate the thermal response of four point-supported glass façades under both uniform and non-uniform thermal loadings. The Coulomb-Mohr criterion and stress intensity factors based mixed-mode criterion are employed to predict the crack initiation and growth, respectively. The glass stress distributions, breaking time and initiation and propagation of crack are presented, using three-dimensional finite element method. It is observed that all the cracks initiate at fixing points, which is attributed to the combination effect of constraining at supporting points and non-uniform temperature distribution. Fixing points changing in horizontal, vertical and diagonal directions has significant effects on glass breaking behavior. Moreover, thermal loading form also markedly affects the time of first crack initiations. The variation tendency of breaking time agrees well with our previous experimental study. It is intended that these results will provide some practical guidelines for fire safety engineers.