Study On Buffering Performance Of Anti-collision Device For Bridge Pier Based On Graded Energy Consumption

In recent years,car-bridge collision accidents have occurred frequently,causing serious casualties and economic losses.In response to the car-bridge collision problem,domestic and foreign scholars have carried out a series of theoretical and experimental studies on the collision of bridge piers,and proposed various anti-vehicle collision devices for old cities and highway overpass bridges.There are many types of anti-collision devices.This paper mainly studies the attached anti-vehicle collision box solution,and uses the existing finite element analysis software to prevent the steel structure anti-collision device,composite material anti-collision device and steel-composite material anti-collision device.The buffer performance analysis was carried out,and the grading energy consumption concept was introduced,and the optimization proposal for the steel-composite material prevention device scheme was further proposed.The main research contents of this paper are as follows:(1)Using LS-DYNA finite element software to simulate the process of 2t light truck and 8t medium truck hitting the pier,analyze the relationship between vehicle tonnage,impact speed,impact angle and vehicle impact.It is calculated that the vehicle collision force increases non-linearly with the increase of the tonnage and impact speed of the vehicle.(2)Simulating the process of the vehicle striking the pier with the anti-collision device,and analyzing the performance difference between the steel structure anti-collision device,the composite device and the steel-composite anti-collision casing.It mainly analyzes the dynamic response process of light-duty trucks and medium-duty trucks with three collision avoidance devices: 30km/h,50km/h,and70km/h.It is calculated that the cushioning performance of the composite anti-collision device and the steel-composite anti-collision device is much better than that of the steel structure anti-collision device,and the final determination is made by comparing the impact force,the energy absorption effect,the collision depth of the vehicle head,and the cost of the device.Steel-composite anti-collision device solution.(3)Further analysis of the process of the 8t medium-duty truck hitting the pier with the steel-composite material anti-collision device at a speed of 70km/h.By setting a plurality of working conditions by changing the width ratio of the composite layer tothe steel structure layer,the outer diameter of the buffer cylinder in the composite layer,the vertical partition of the steel structure layer,and the number of lateral partitions,each method based on numerical simulation calculation is studied.Anti-collision performance in the form of arrangement.It is calculated that when the composite layer width is 20 cm,the steel box layer width is 30 cm,the composite buffer cylinder outer diameter is 9cm,the number of vertical partitions and the number of transverse partitions in the quarter steel box are both 0,steel-The composite anti-collision device has the best cushioning performance.(4)Based on the concept of grading energy consumption,it is proposed that the medium-sized truck of 8t will not simulate the steel structure of the steel-composite anti-collision device with 50km/h impact,and further simulate the impact process of medium-sized truck.It is calculated that when there is no vertical partition in the quarter steel box and only three horizontal partitions are provided,the hierarchical energy consumption concept can be satisfied,and the medium-sized truck in the 8t is hitting at 70km/h,the maximum collision The force is reduced by 46.8%.The anti-collision device is applied to the 2t light truck impact process.It is calculated that the device also meets the hierarchical energy consumption concept,and the maximum vehicle impact is reduced by 57.2% under the impact of a 2t light truck with 70km/h..In summary,the structure of the anti-collision device is reasonable.