Research And Application Of New Types Of Truck Mounted Attenuator

Car rear-end truck is one of the highest casualty rate traffic accidents,causing a large number of casualties and property losses every year.If a car collides rear-end with a truck at a high speed,the rear protection device of the truck cannot provide good protection for the car driver based on the extent to which it can absorb energy,and may also cause the car to penetrate the bottom of the truck.Installing a Truck Mounted Attenuator at the rear of a truck can not only effectively absorb the collision energy when a car collides with a truck,but also protect the safety of the drivers and passengers in the car.Due to the current domestic laws and regulations on Truck Mounted Attenuators are not perfect,their application is not widespread.Therefore,based on the existing domestic and foreign related products,and the latest standard MASH-2016 of the American "Manual for Assessing Safety Hardware",a new type of Truck Mounted Attenuator with different structures has been designed through vehicle collision simulation.Firstly,the basic finite element theory related to compression and collision is derived,and the display center difference method is determined as the finite element analysis method used in this article.The finite element analysis and solution are performed using Hyper Works and LS-DYNA joint simulation.The static mechanical properties of aluminum honeycomb,a filling material for Truck Mounted Attenuators,were measured using a quasi static compression test with a compression speed of 1 mm/min.The aluminum honeycomb was subjected to drop weight impact tests with impact velocities of 3 m/s,5 m/s,and 7 m/s to determine its dynamic mechanical properties.The finite element modeling and simulation of the sample were conducted,and the simulation results were compared with the experimental results.The static and dynamic simulation errors were within 5% and 7%,respectively,verifying the correctness and effectiveness of the aluminum honeycomb finite element model.Secondly,finite element modeling of vehicle collision related models is conducted,including cars,trucks,aluminum honeycomb structures,and new Truck Mounted Attenuators.When modeling a car,an acceleration sensor is installed under its rear seat.After the collision simulation is completed,the acceleration data of the car during the entire collision process is output.Then,the collision simulation between car and rigid wall and aluminum honeycomb structure is carried out,and then the aluminum honeycomb structure is installed at the rear of the truck to conduct the collision simulation between car and truck.The simulation results show that the aluminum honeycomb structure can not only prevent cars from penetrating the bottom of the truck,but also effectively absorb collision energy.Finally,a new type of primary Truck Mounted Attenuator and four types of multi-stage Truck Mounted Attenuators with different structures were designed,and then they were installed at the rear of the truck to conduct vehicle collision simulations with initial speeds of70 km/h and 100 km/h.By analyzing the collision simulation results,it can be seen that the maximum acceleration of the primary Truck Mounted Attenuator is reduced by 55%,and the optimal scheme of the multi-stage Truck Mounted Attenuator is reduced by 50%.This provides certain theoretical directions for the actual application of Truck Mounted Attenuator.