| In recent years,traffic accidents of vehicles hitting piers and barriers and son on have occurred frequently in China.When a vehicle crosses medium separation divider,rushes out of road,or falls from bridge,it will cause serious casualties,property loss,and economy loss.Therefore,the research on the collision performance of guardrails has become a topic with general concern.Aiming at the safety of car-crashing-barriers,scholars have conducted a series of related theoretical and experimental studies,and proposed a variety of new materials and structures for car-crash-prevention barrier facilities.With combination of research and analysis,this article conducted in-depth research on the barrier with high-efficiency energy-absorbing alloy plus composite.Using finite element analysis software,the crash cushioning performance of this new type barrier was compared with the traditional steel barrier.Further,an optimization plan for this barrier with new material was proposed.This article’s main research scopes is followed:(1)First of all,according to the design requirements and safety protection standards of anti-collision barriers,we studied different materials’ performance such as steel structure,composite material,and energy-absorbing alloy,and adjusted the structural dimensions,and initially determined the type of anti-collision barrier.(2)We established finite element models of the barrier structure and vehicle using LS-DYNA,simulated the dynamic response process of the vehicle impacting the energyabsorbing alloy-composite material barrier and the traditional steel structure guardrail,mainly by analyzing the process of the vehicle striking the guardrail at angles of 10°,20°and 25° with speed of 60 km/h,65 km/h,and 70 km/h,respectively,compares the cushioning protection performance between the two types of barriers.The computation results show that,with the increase of impact angle and impact speed,all the values of head acceleration,impact force,barrier beams’ deformation,and barrier’s total energy absorption increase.The impact force of this new alloy-composite barrier compared to steel barrier is significantly reduced,cushioning performance of this new alloy-composite barrier is shown excellent,the collision acceleration inside the car is significantly reduced,and the safety of the occupants is effectively protected.(3)In-depth simulation and analysis was made for the process of the vehicle impacting the high-efficiency energy-absorbing alloy-composite barrier at speed of 70km/h and angle of 20°.Cases were set up by changing the thickness of the barrier beam which is the thickness of the composite layer,and the size of the energy-absorbing alloy bar.In addition,the anti-vehicle-collision performance of the barrier under each arrangement was studied based on numerical simulation and calculations.The computation results show that,when the thickness of composite layer for the first and second beams is 3mm,and the thickness of composite layer for the third and fourth beams is 5mm,and the diameter of the energy-absorbing alloy bar is 15 mm,the structure arrangement is reasonable,the protection performance is good,and cost-effective is excellent for the energy-absorbing alloy-composite barrier. |
