Mechanical behavior and failure mechanism of membrane-roof cable dome under high-heat-release fire

This study aims to obtain the fire responses and smoke-evolution laws of membrane-roof cable domes subjected to high-heat-release fires. A cable dome structural model was designed with a span of 12 m, rise of 1.5 m, and real polytetrafluoroethylene membrane roof, together with a 4-m-high enclosure, and conducted a high-heat-release fire test. The failure mode of the cable dome under fire was observed and the differences in the response behaviors and temperature-field distributions of the structural specimens after membrane-roof failure were identified. The smoke evolution within the membrane-roof cable dome was analyzed via tests and simulations. The numerical simulation results and test results were in close agreement. The results showed that, in the early stages of fire, the temperature within the structure increased, the membrane roof expanded, and the internal forces in the cable dome specimens decreased sharply. In the middle stages of the fire, the internal forces in the cable dome specimens became zero, and only the self-weights remained. Moreover, the heat-sealed seams of the membrane roof cracked and the internal temperature dropped. In the late stages of the fire, the internal forces of the cable dome specimens gradually recovered. After the membrane roof was damaged, the structure's smoke exhaust outlet shifted from the door opening to the damaged membrane-roof locations, and the internal smoke evolution of the membrane-roof cable dome could be divided into four stages. This study systematically reveals the mechanisms of temperature field distribution and mechanical response evolution of cable dome structures subjected to high-heat-release fire.