The Research Of The Fire Resistance Of Steel Frames After Subjecting To Impact Loads

The research about the response of important structures subjected to impact load and fire is a very difficult problem due to inter-disciplinary contributions, and it also is critical to safety of countries. Since 1980's, a large number of important buildings through out the world have been destroyed by impact load in terrorist attacks, in which"9.11"is the most catastrophic incident and killed many people's lives and cost millions of dollars. It challenged the development of the prevention of progressive collapse. There are many very important structures which are symbols of politics and economy in our country. Once the important structures are damaged by impact load and fire in terrorist attacks such as"9.11", the losses should be huge. So studying the response and improving some effective methods to prevent the structure from collapsing are very urgent.In this paper we study the structural bearing capacity in fire after subjecting impact load using the finite element software ABAQUS. This study includes three parts, the first part is the establishment of the finite element model and comparing the result between the test and FEM. It includes introducing the test and discussing the process of establishing the finite element model in detail such as the constitutive relation of the material, the finite element program, the element type, the explicit method, the loading process and so on. Then we compare the result of the finite element method and the test; we find that the two results agress. In the second part we use the FE model studying the bearing capacity in fire of the structure elements after subjecting impact load. We use the software MATLAB get a coefficient that is a ratio of the time t 0 and t 1 , where t0 is the resistance time of the structure in fire when the structure was damaged by impact load, and t1 is the resistance time of the structure in fire without damage. This coefficient can give a instruction when we design elements in fire after damage. The third part we study the method to improve the bearing capacity in fire of the structure. Here we use two methods, one is adding the thickness of the fireproof paint, the other one is setting up cable under the beam. By using the finite element...