Research On Simplified Mechanical Model Of Vehicle Impacting With Bridge Pier And Protective Effect Of Barrier

In recent years,the probability of vehicle collision with bridge piers has increased,causing serious economic losses and casualties.The collision safety of bridge piers has attracted more and more attention.This paper uses numerical simulation and theoretical analysis to discuss this problem,especially the optimization and expansion of the simplified mechanical model of vehicle impact piers.And the mechanical properties of the impacting piers under the protection of the barrier are studied.The specific research work includes: 1)Analyzed the mechanical properties of the rigid bridge piers in front of the light truck and medium truck models.Detailed parameter analysis was carried out on the rigid front pier of the vehicle,including: truck impact speed,mass,truck cargo stiffness and cross-section size of the pier.The impact mechanics characteristics of the two trucks were compared and analyzed.2)The existing simplified vehicle crash mechanics model is optimized by particle swarm optimization algorithm.By comparing with the fine finite element model and the time history curve of the simplified model before the optimization,the effectiveness of the simplified vehicle crash model after optimization is verified.It also shows that the model can be applied to light trucks and medium truck models,and has the potential to continue to expand;3)The coupled mechanical model of the vehicle impacting elastic pier is established.The model can analyze the time history of the vehicle impacting the elastic pier,and can quickly calculate the truck impulse,energy and impact force time history,the bearing reaction force of the pier and the lateral displacement.Key parameters such as time history,compared with the fine finite element simulation,the analysis time is greatly reduced;4)Analyzed the influence law of the barrier on the impact of the vehicle on the pier,and qualitatively evaluated the safety of the collision of the pier under the protection of the barrier.The trajectory shape of the vehicle and the barrier after collision,the collision mechanism of the vehicle-bridge pier under the protection of the barrier and the peak of the impact force of the vehicle are studied,and the protective effect of the barrier is discussed.In the end,the paper summarizes the rules and conclusions obtained from the research work,and points out the problems and deficiencies in the research process,and puts forward opinions and suggestions for the next research.