Research On Damage Effect Of High-Speed Train Window Glass Under Blast Load

In the domestic and foreign railway transportation system,accidental explosion accidents and purposeful bomb attacks occur from time to time,threatening the running safety of trains.When the explosion occurs on the side of the train,the explosion impact load mainly acts on the side wall,door,window glass and other parts of the vehicle body,and the window glass is more easily broken under the action of strong impact load.Survey data show that 70% of the casualties were caused by high-speed flying debris after the explosion shock wave damaged the glass.At present,there are few reports on the dynamic response of high-speed train window glass under the action of explosion shock wave,and the research on its anti-explosion performance is still in its infancy.The research on the damage effect of the window glass can improve the anti-knock performance of the train,effectively reduce the secondary damage caused by the high-speed splashing glass fragments,and also provide a theoretical reference for the running safety and structural optimization of the train.This paper takes the window of the second-class passenger compartment of the CRH380 A EMU as the research object,considering the effect of the inert gas layer between the glass plates and the influence of the PVB glue,using the CONWEP calculation model combined with the ALE multi-substance algorithm and the CFD method in the side explosion environment.The overpressure changes at the center of the window glass and the effect of the shock wave on the inner and outer glass under different blast distances,different equivalents of TNT,and different blast heights and the effect of the shock wave on the inner and outer glass are studied.The damage characteristics of the inner and outer glass of the window;at the same time,the CFD method is used to explore the pressure change of the outer flow field under the action of explosion load and the distribution law of the inner flow field of the high-speed train under different window glass failure conditions,and to explore the near-ground side explosion environment.,the pressure distribution of the dummy in the car and the pressure changes of the dummy’s head,thorax,calf and ribs at typical positions,combined with the overpressure evaluation criteria to judge the damage of different dummies.The research results show that the CONWEP calculation model combined with the ALE multi-material algorithm can accurately and efficiently simulate the process of the shock wave diffusing to the explosion-facing surface of the car body and diffracting at the top of the car body to gradually disappearing.When the distance is 2.5m,the shock wave overpressure peak of the outer glass of the window reaches 971.4k Pa,and the maximum stress of the inner and outer glass is 299.1MPa and 330.4MPa,respectively,resulting in a large area of the inner and outer glass falling off.When the TNT equivalent is constant,the displacement peak value,velocity peak value,and acceleration peak value of the center of the window glass attenuate exponentially with the increase of the blast distance,and as the equivalent TNT increases,the shock wave is more easily attenuated,and the positive pressure duration is longer.short.In addition,with the increase of time and the propagation of shock waves in the air during the explosion,the longer the explosion distance,the wider the positive pressure area,and the smaller the explosion distance,the greater the pressure difference between the overpressure peak point on the car body and the window glass.big.When the window glass is broken,the explosion shock wave reciprocates in the car and reciprocates on the front and back explosion surfaces of the car in a hemispherical shape.The incident wave superimposes the reflected wave,causing the pressure accumulation effect of some dummy body parts.Comparing the overpressure evaluation criteria,It is inferred that the physical damage on the body surface of the dummy at the typical position.The dummy at the horizontal projection point of the explosive in the carriage died under the action of the shock wave.