Numerical Analysis Of Response Of Simply Supported Steel Box Girder Bridge Under Fire And Explosion Of Tank Truck

Highway bridge as an important infrastructure to connect China's high-speed road network,in the country's economic development and military defense plays a vital role,with the name of the sea throat.Steel bridge is a kind of steel structure bridge,which has the characteristics of modular processing,simple construction and saving construction period,and is widely used in urban overpass,highway and large span cable-stayed bridge.However,regional short-range fuel and dangerous goods transport is also increasing with the industrialization of the city,especially as a tanker This flammable and explosive means of transport is very common on the road,due to a car accident causing the tanker to fire on the bridge The phenomenon of more and more steel box bridge as a steel-based bridge structure,tanker fire high temperature and explosion impact will produce high temperature softening effect of steel and high strain rate effect,so the study tanker fire explosion under the steel box The dynamic response of the bridge is very meaningful.In this paper,a large-scale simply supported steel box bridge is an engineering example,through numerical analysis of tanker fire explosion under the simply supported steel box bridge response law.The main research contents are as follows:(1)Based on the study of domestic and foreign research data and corresponding norms under the fire and explosion,that is,considering the high temperature and high strain rate effect of the steel structure of the material model,while summing up the TNT explosives and air material model;described the structure of heat transfer and explosion shock Basic theory.Which provides the material parameters and calculation basis for the subsequent response to simulated high temperature and blast impact.(2)The finite element software ANSYS Workbench and the explicit dynamic software AUTODYN are used to analyze the bridge response of simply supported steel box bridge under the impact of high temperature fire and single explosion.The temperature distribution of the bridge under different fire scenes and the bridge response of the bridge at different times are obtained.At the same time,the propagation of TNT in the air is obtained by using the AUTODYN Euler algorithm to obtain the real explosive impact load,and the explicit dynamic analysis method The dynamic response of bridge under different working conditions is obtained.(3)According to the tanker as a flammable and explosive transport,the method of analyzing the response of the explosive bridge after the fire is put forward.The numerical response is used to analyze the bridge response of the steel box bridge fire after high temperature explosion.(4)Based on the numerical analysis of the bridge response under the fire and explosion of the tanker,it is concluded that the fire in the semi-enclosed environment has the greatest influence on the bridge.Under the low intensity explosion,the bridge has a greater response than the bridge.The high temperature mainly reflects the softening of the steel of the simply supported steel box bridge to reduce the anti-explosion ability of the bridge.