Simulation Study On The Crashworthiness Of W-beam Guardrail

W-beam guardrail plays an extremely important role in our country,to prevent the outside the way,to reduce the occupant of the vehicle damage degree and to reduce property loss plays the vital role.In order to reduce the severity of the collision accident and ensure the safety of passengers,it is very important to improve the protection performance of the W-beam guardrail at both ends of the highway.The performance of the guardrail mainly depends on the structure of the guardrail and the absorbability of the materials used in the guardrail,so the good absorbability of the material can greatly improve the anti-collision ability of the guardrail.The intermediate manganese steel has high strength and plastic level,and has obvious advantages in energy absorption.Therefore,we can consider the application of the medium manganese steel in the guardrail to improve the anti-collision energy of the W-beam guardrail.In this paper,a common type A-waveform beam guardrail is studied,and it is used to simulate common vehicle collision guardrail by LS-DYNA.In order to make the results more universal,the three models of car,SUV and passenger car were selected and three collision speeds were adopted,namely 60,80 and 100km/h respectively.Firstly,the accuracy of the three car models was verified by establishing the frontal crash model,and then three models of vehicle crash guardrail were identified.In this paper,the location of the collision point is investigated.Through the simulation analysis,it is found that the acceleration of the vehicle is the maximum when the collision point is at the front of the column.When the collision point is located at the rear of the column,the guardrail produces the maximum transverse deformation.Then compared the crashworthiness of Q235 common carbon steel guardrail and the medium manganese steel guardrail.The maximum acceleration of the seat and the energy absorbed by the guardrail are used as the evaluation indicators.The results show that the crashworthiness of the medium manganese steel guardrail in various cases is better than that of Q235 ordinary carbon steel guardrail.In addition,it further explored the use of medium manganese steel in the guardrail plate,and the thickness of the beam can be reduced by 1mm and can save 25% of the steel when it reaches the crashworthiness of Q235 ordinary carbon steel guardrail.In the end,the relative structural parameters of the medium manganese steel guardrail are optimized by orthogonal test,and the crashworthiness of W-beam guardrail is further improved.The analysis found that when the column spacing is 4000 mm,the thickness of the beam plate is 3mm,the thickness of the resistance block is 4.5mm,and the column thickness is 5.5mm,the crashworthiness of the medium manganese steel guardrail is the best.Compared with the Q235 ordinary carbon steel guardrail,this parameter level of the medium manganese steel guardrail is improving the crashworthiness,and also saves the steel quantity.