Study On The Fracture Behavior Of Float Glass

Glass is widely used in modern buildings.In the fire environment,such behaviors as glass breaking and failing off will bring new vents and fire spreading channels,which will bring more harm.In order to better understand various factors affecting glass fracture in fire environment,this paper builds an experimental bench to simulate glass fracture behavior in fire environment and sets up a variety of experimental conditions,and studies the glass fracture behavior in fire environment from macroscopic and microscopic perspectives by using experimental and numerical simulation methods.This paper selected the construction of the most commonly used float glass as the research object,first of all four edges,and around the vertical cover,upper and lower levels of cover and all hidden box for four different way cover glass curtain wall thermal radiation experiments,using the failure time of fire heat release rate for the first time,glass,crack propagation behavior,falls off phenomenon important parameters,such as crack and crack position and get covered the four edges of the glass the most prone to rupture,half hidden frame glass curtain wall compared with four edges covered glass curtain wall has better fire prevention performance;For the glass with full hidden frame,the change of fire source position will have significant difference to the fire performance.Secondly,a comparative study is made on the common four-point support mode and the four-side shelter mode of the thermal fracture behavior of the curtain wall.It is found that the crack position of the frame support glass is generally located at the shelter edge with the maximum temperature difference,while the point support crack position is at the support point.By adjusting the straight line distance between the center of the fire source and the direction of the glass thickness,the results show that there is a close relationship between the crack complexity and the location of the two supporting modes within the critical position of the fracture.Finally using PFC2D procedure from the microscopic Angle,based on the glass under the load of high temperature thermal coupling model and discrete element model,simulates the glass micro failure process under high temperature,fire analysis of glass surface micro crack propagation characteristics,quantity and distribution of crack,reveals the glass at high temperature under the load of micro crack initiation and extension mechanism of expansion process.