| The easily happened fracture and fall out of windows glass under the case of compartment fires could significantly influence the evolution of fire. Lots of works about the fracture of windows glass under the strong and vertiginous heat flux in fires have been done. There are two types of building glass curtain walls, point supported and frame supported, and glass in the structure of the later has two different zones, one is the exposed zone and the other is the shaded zone due to the frame. The thermal expansion of the heated exposed zone in the middle area of a glazing pane would put the shaded cooler edge in tension, which would cause fracture to the glass.The purpose of this thesis is to study the thermal stress distribution and the subsequent fracture and crack propagation under fire conditions of a frame supported glass curtain wall, and gain a further understand of the fall out of glass.The phase-field method (PFM) widely used in modeling microstructure evolution is extended to simulate the complicated thermal stresses within windows glasses due to fire exposure. The computed results are validated through comparisons with those provided by analytical solution and finite element computation. Thermal stress distribution in a glass pane under uneven incident heat flux is simulated, and the effects of thickness, shading width and size of glass pane found in experiments and simulations are explained from the aspect of thermal stress analysis.Then, take the concept of equivalent strain we can treat the crack as a small opening hole in the phase-field method. A procedure to predict the crack path in glass under fires scenario is proposed using the criterion of crack propagation direction based on stress intensity factors. The process is also validated through comparisons with analytical and experimental solutions. At last, the crack path under fires is simulated and the effects of initial position of crack and different boundary conditions are investigated. |
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