Numerical Simulation Of Structural Reliability Of A Concrete Structure In Fire

As China's urban construction development, all kinds of high-rise buildings and large-span structures have emerged. These new buildings generally have numerous room, large spatial span and complex structure, also the level of mechanical and electrified is in high degree, which meet the urban development and social needs of production, at the same time also greatly increase the chances of building fires and the fires are more difficult to stop. In order to provide a theoretical basis for fire prevention, fire rescue and post-disaster damage assessment, exploring the structure reliability of the building in case of fire is of great practical significanceNow the safety research of structure under the fire is mainly based on the ISO834 standard temperature curve. While the ISO834 standard temperature curve is a theoretical curve, does not reflect the fire impact of combustible materials amount, type, distribution and construction ventilation conditions. Second, when do the reliability analysis, generally have not limit state equation. While direct use the Monte Carlo simulation analysis, are facing the problem of huge number computationIn order to solve these two problems, this paper, accurately reflect the actual scene of the fire situation by the fire dynamics simulation, gain better actual conditions of temperature distribution in the fire, on this basis, calculate reliability using response surface method based on uniform test and thus significantly reduce the required amount of calculation. The basic idea is to use uniform test method to group with the fire affecting factors,get the samples of analysis; Then use the CFAST software of fire development and smoke movement, carry out a sample calculations, access to the fire temperature field data; and then the fire temperature field data will be as boundary conditions, use the ANSYS software and numerical analysis methods coming from concrete test to calculate the internal forces and bearing capacity of structure; Finally, establish limit state equation based on the maximum temperature, fire duration, the internal forces and limit state bearing capacity of structure,solving the reliability index and failure probability of load-bearing components at different fire time.In this paper, the reliability of a concrete structure in a fire was analysised. The results show, under the premise of significantly reduced the calculation, using such a solution can more rapid access to component reliability index and failure probability.