Modeling And Simulation Of Urban Transport Network Invulnerability Under Cascade Failure

The safe and stable operation of transportation network system plays a vital role in maintaining the rapid growth of social economy and the stability of people’s lives.Any unexpected or interference events in the network can lead to the failure of some nodes or edges,which can cause cascade failure and other cascading reactions,and then cause serious impact or damage to the traffic network system.Therefore,it is necessary to analyze the important hub stations and key operation areas of the network,to understand and master the process and rules of failure propagation in the traffic network,to establish the index of survivability measurement,to study the survivability characteristics of the urban transport network under different attacks,to prevent chain reaction by allocating defensive resources reasonably,to formulate effective emergency measures for safety management and to improve urban transport.The quality of service and the degree of security are of great significance.This paper takes the invulnerability of urban transport network as the research object.Firstly,it briefly reviews the research status of traffic problems based on complex network theory at home and abroad,and briefly describes the basic theory of complex network,the characteristics of urban transport network and the concept of invulnerability.Secondly,by analyzing the influencing factors of urban transport network survivability,a new method of urban transport network survivability measurement is proposed by introducing two indicators of "node survival rate" and"iteration number" based on "outcome" and "process" Thirdly,considering the situation of multi-node failure,the dissemination mechanism of failure in urban transportation network is analyzed,and the cascade failure-resilience model of urban transportation network is constructed when multi-node failure occurs,and the solution algorithm and simulation verification are given.Finally,in view of the difference of nodes in urban transport network,the method of determining the capacity coefficient is given based on the characteristics of nodes,and the model of urban transport network with variable capacity coefficient under cascade failure is constructed.At the same time,the solution algorithm and simulation verification are given.