| Currently, in finite element simulation analysis of multilayer frame for progressive collapse, few research adopt three-dimensional solid elements to simulate all components, and the relevant literature that considering the effects of seismic design and filler wall’s stiffness simultaneously is more rare. For a more realistic simulation of space failure modes and ultimate bearing capacity of the frame progressive collapse, and research the influence of seismic fortification intensity and filler wall’s stiffness, this paper use nonlinear finite element analysis software which developed based on virtual laminated theory, and select 20 nodes three-dimensional solid degenerate units to analysis the vertical progressive collapse resistance performance of frame models that considering the above influencing factors, the main research work of the article is as follows:1. By building finite element models to simulate a R.C. Frame progressive collapse test that considering the effect of floor, comparing the important result of finite element analysis and the original progressive collapse test, for example, loading process, framework destruction, the structure’s load-displacement curves an so on, it is verified that this software and its theory can be used in the study of frame’s resistance of progressive collapse that considering the role of floor, and has nice calculation results. This lay the foundation for the following research to make sure it can carried on under considering the effect of floor.2. Introducing the seismic intensity factors, and design the structure for the same framework as the requirements of different seismic intensity. According to the design results, establish accurate space finite element analysis models, use dismantle component method to remove different parts of the columns, then analysis vertical progressive collapse resistance performance of frames designed based on different seismic intensity. By comparing different seismic intensity models’ stress variation and destruction process and destruction mechanism, draw the conclusion: In general, the higher seismic intensity, the better structure performance of resisting progressive collapse; With the improvement of the seismic fortification intensity, the increased degree of the frames’ ultimate bearing capacity to resist progressive collapse are different while dismantle different parts of the columns; When demolish different parts of columns, the improvement of the structural resistance of progressive collapse not all depend on the improvement of seismic intensity, sometimes it depends on the improvement of floor’s strength.3. Introducing the infilled wall factors. First, simulate and analysis a real test about the performance of infilled wall, the results show that the finite element analysis program used herein is suitable for the infilled wall nonlinear analysis. Secondly, by sorting out and analyzing mechanism about how the infilled wall play its participating role in framework, propose a kind of infilled walls mechanical model in progressive collapse. Then, arrange different layers of infilled walls(except the bottom layer) for the same plane frame and analysis their ultimate bearing capacity, ultimately determine the impact of infill walls for four layers(i.e. five-story frame). Finally, arrange four layers infilled walls for frame demolished different parts of columns of different seismic intensity, and analysis their ultimate bearing capacity to resist vertical progressive collapse, by collating the results to draw some useful conclusions about the impact of infilled wall. |
PDF Full Text Request