Research On Performance Of Resistance To Fire For Pre-stressed Composite Space Truss

Pre-stressed composite space truss is a kind of space structure system developed on the basis of space truss and the concept of prestress, which consists of steel and reinforced concrete. It is widely used in the stores and schools, which have condensed human in long time. If the pre-stressed composite space truss collapses in fire before people leave the building safely, it will cause large-scale casualties and loss of properties. But at present the study on it mostly focus on its static and dynamic properties, the tension of the cable and its layout. Individual paper used the standard fire temperature-time curve to make a research on fire resistance of pre-stressed composite space truss. There is few document employing performance-based fire safety design to study the fire-resistant behavior in global structure until recently. Therefore, it is of great significance in theory and engineering practice to make a study on fire resistance of pre-stressed composite space truss in global structure by employing performance-based fire safety design.In this thesis, one pre-stressed rectangular square pyramid composit space truss is the project background. The fire-resistance property in global structure and the safety is analyzed with the performance-based fire safety design. Firstly, the target of performance-based fire safety design is set up, then the actual time-temperature curve of structural elements can be calculated through utility temperature elevation empirical formula in large space fire. Secondly, using finite element analysis software ANSYS for thermal analysis, after that, the results of the thermal analysis are loaded in the structure, the entire deformation and the fire-endurance time can be received through structural analysis by ANSYS again. Thirdly, fire-resistance safety design and evaluation of the structure can be carried on by using decision criterion. Lastly, the fire-resistant behavior of pre-stressed composite space truss is investigated by changing the parameters such as length-width ratio, height of space truss and fire efficiency.