The Study On CFST's Temperature Field Under High Temperatures (Fire)

Fire is one of the most numerous and destructive disasters among all kind of the disasters. The economic loss it brings directly is only less than drought and flood, and especially in recent years , the frequency of it is the first of all kinds of disasters, because buildings become high stratification cosmically and complex they are used, factors that lead to fire increase along with them. The dimension of fire also enlarge with them, architecture fireproofing arouse people more and more regard, so it is very important for people to seek for the new type of structure that strongly resisting fire.CFST is a new type structure between steel and reinforced concrete . CFST utilize the mutual restriction of material steel and concrete, and make up the shortage of them, so the virtue of the two kinds of material can be exerted.The bearing capacity of CFST elements under high temperatures (fire) will be reduced with the temperature ' s raise . In order to confirm the fire endurance capacity of CFST elements , the temperature field of CFST under high temperature must be confirmed first, and then we can research the CFST elements dynamical and static capacity. The temperature field of CFST element is also the foundation of evaluating the injuring degree and renovating of reinforce design.By combining heat transfer theory with computer numerical value simulation , this study simulates temperature field' s variety of CFST with high temperature . Main questions solved include founding CFST standard fire experiment' s math model and physical model , confirming environment and heat physical parameters of CFST, using finite difference method to solve by Visual Basic language as develop flat, so identifying all kinds of sections (circle, square, rectangle, and so on) CFST' s temperature field with various boundary conditions (one-side, two-sides, three-sides, four-sides subjected fire and so on) in high temperature.In order to make it reliable, we compare the result with standard fire experimentation' s data and made some amends for math model and physical model, so the research can reflect standard fire experimentation' s condition, and can be applied to confirm the fire endurance capacity of CFST elements.The research have some difficulty and deepness. The result can be applied to capacity analyses of CFST structure subject to fire . It also provide basic math model for seismic resistance reinforce of CFST structure, so it has important engineering apply value.