Research On Evacuation Model Based On FDS+EVAC

With the development of the society and the acceleration of the process of urbanization,more and more complex multi-functional building space and public space are beginning to appear,making the pedestrian evacuation more and more complex and changeable.Therefore,it is of great scientific and practical significance to carry out the study of pedestrian evacuation and simulation,to study the evacuation characteristics and evacuation process,to provide key data and reasonable suggestions for public evacuation,and to provide evacuation design for the building and city designers.On the basis of summarizing the predecessors' research on evacuation simulation,this paper selects a more universal social force model.In view of its existing shortcomings and problems,have carried out a thorough qualitative and quantitative analysis.On this basis,the model is optimized.The optimized model includes the following points and conclusions.(1)According to the unreasonable movement of pedestrians in the FDS simulation,the pedestrian prediction model is added to make pedestrians not only influenced by the forces of the pedestrians around themselves,but also by judging whether the pedestrians will collide at a certain time in the future,select pedestrians that may collide,and analyze the direction and size of the pedestrians' force.Three An independent step to judge the possible collision with other pedestrians on the evacuation route,so as to adjust the evacuation path and avoid collision.(2)In the case of real evacuation,people often observe that pedestrians follow others when evacuating,thus forming queues,deriving channelization,group movement and other evacuation phenomena,but FDS simulation can not effectively restore the phenomenon caused by the pedestrian psychology,so a new pedestrian attraction is added,and the related parameters are analyzed and designed for it.In order to determine,follow the angle,the free movement,the expected velocity direction and the current speed and the pedestrian distance,the expression of the pedestrian attraction is established and integrated into the model.(3)For many parameters in FDS simulation,a number of simplified constants can not be used to effectively restore some of the different model attributes of pedestrians.The parameter preprocessing mechanism is added,and the ANFIS fuzzy processing toolbox in Matlab is used.According to the experimental data,the pedestrian interaction intensity Ai and the pedestrian interaction range Bi are fuzzy processing to make it more effective and conforming to real evacuation.(4)Through the twice experiment,the validity of the optimized model is verified,the traditional model,the optimization model and the experimental data of the same working condition are compared and analyzed,and the error between the optimized model and the experimental data is smaller,and the error of the traditional model is reduced by about 22%-69%.It is proved that the model optimization is effective.