Simulations On The Damage And Collapse Of The Cable-Bridge Tower Under Blasting Loads

Bridges are important junctions of traffic transportation,and of great importance and significance in land transportation system.During its whole life cycle,the bridge may be attacked by guide missiles,terrorist attacks,occasional blasting and so on.As one of typical long-span bridges,cable-stayed bridges are at a high risk of terrorist attacks.This paper carried out the study on numerical simulation methods and failure mechanisms of the bridge under blasting loads of large yield TNT.The main contents are followed below:(1)Study on blasting loads and ALE multi-material fluid-structure coupling computation.This paper used this numerical method to analyze the explosion of large yield TNT in free air,compared the results of the numerical with that of empirical equations,and on this base verified the rationalization of the numerical method about the simulation of large yield TNT explosion in free air.Meanwhile,the paper apply this numerical method to simulate a experiment of explosion on RC plank for verification of the availability of material constitutive models and ALE multi-material fluid-structure coupling computation.(2)Study on the method of finite element numerical analysis.According to the characteristics of damage in different stages of engineering structures,this paper carried out the necessity of dividing the explosion damage process of engineering structures into different stages and pointed out the defect of current numerical method,on this base studied the basic idea of staged and continuous coupling method as well as the steps of the finite element numerical analysis.Then,the feasibility of staged continuous coupling method was verified by applying it to the numerical simulation of damage of a simply support RC beam under blasting loads.(3)Study on the failure mechanism of cable-stayed bridge tower under blasting loads.According to a cable-stayed bridge engineering model,this paper set up an A shaped cable-stayed bridge tower's finite element model,and used the “three-stage continuous coupling” method to simulate the tower's whole collapse process under blasting loads,studied the process of bridge tower local and overall failure respectively and analyzed the damage mode and damage mechanism of the overall response stage.