Study On Collision Modeling And Simulation Optimization Of Corrugated Beam Guardrail On Superhighway

Waveform beam guardrail is an important safety barrier to protect the occupant on the highway.When the vehicle crashes into the guardrail out of control,the guardrail can prevent the vehicle from rushing out and guide the vehicle back to the normal track.In this paper,finite element simulation software is used to study the protective performance of double and three wave guardrail.To explore the safety performance of double wave guardrails on ordinary highways,collision simulations were conducted using finite element software LS-DYNA and Hyper Mesh.The collision speeds were set at 60,80,100,and 120 km/h,and the collision angles were 5°,10°,15°,and 20°.The guardrail deformation,vehicle synthetic acceleration,and system energy under different collision conditions were analyzed.The results indicate that with the same collision angle,the collision speed increases,the maximum dynamic deformation of the guardrail increases,the range of composite acceleration fluctuations increases,and the degree of vehicle damage increases.When the collision speed exceeds 100 km/h,the double wave guardrail cannot meet the safety protection requirements.To explore the safety performance of the three-wave guardrail on superhighway,based on the research on the double-wave guardrail on ordinary expressway,a collision simulation model is established in Hyper Mesh with the collision conditions of speed 100～180 km/h and angle 5～20°,respectively.By analyzing the maximum dynamic deformation and energy absorption of the guardrail under different collision conditions,The vehicle exit angle and synthetic acceleration are used to evaluate the safety of the three-wave guardrail.The results show that the three-wave beam is the main energy absorbing component in the guardrail system.With the increase of the collision speed and angle,the energy absorbing ratio curve of the guardrail increases first,then decreases and then increases.When the collision speed is 160km/h and the angle is 20°,the maximum dynamic deformation of the guardrail is more than750 mm,and the vehicle exit angle is more than 60% of the entry angle.When the collision speed is 140 km/h and the angle is 20°,the peak synthetic acceleration of the vehicle is greater than 20 g.Therefore,the three-wave guardrail is used to design superhighway with speeds below 140 km/h,and the protective performance meets the safety requirements.To investigate the impact of collision velocity,collision angle,waveform beam thickness and column spacing on the safety of three-wave guardrail on superhighway,5 sets of single factor and 16 sets of multi-factor experiment schemes were designed.Hyper Works and LSDYNA software were used for collision simulation,and regression analysis of simulation experimental data was conducted with SPSS.The results show that when the beam thickness is5 mm,the protection performance of the three-wave guardrail is improved better.When the column spacing is 2000 mm,although the maximum dynamic deformation of the guardrail is reduced,the peak value of the synthetic acceleration of the vehicle still exceeds 20 g.The maximum dynamic deformation and tripping resistance of the guardrail are directly proportional to the collision speed,collision angle and column spacing,and inversely proportional to the thickness of the waveform beam.The synthetic acceleration of the vehicle is proportional to the collision speed and angle,and inversely proportional to the thickness of the waveform beam and the distance between the columns.To improve the protection performance of the three-wave guardrail on superhighway,orthogonal optimization design of the guardrail was carried out by selecting four factors,including the thickness of the corrugated beam,the thickness of the block,the thickness of the column and the distance between the column.The optimal combination scheme was selected according to the conversion rate corresponding to each factor,and the collision speed was 140km/h and the collision angle was 20°.The protective performance of the guardrail before and after optimization is compared and analyzed.The results show that the maximum dynamic deformation is 564.8 mm,the peak acceleration is 19.14 g,and the energy absorption of the optimized block is increased by 8.89%,the energy absorption of the column is reduced by6.03%,and the protective performance of the optimized guardrail is improved.