Investigation On Crashworthiness Of Hydrogen Fuel Cell Vehicle

Hydrogen fuel cell vehicle is a new energy vehicle.Compared with the traditional fuel vehicle,the hydrogen has zero emissions,zero pollution advantages.Itis currently recognized as the cleanest vehicle in the world.At the beginning of the hydrogen fuel cell car,it catches the widely attention of many scholars.However,the safety and reliability of the hydrogen fuel cell vehicles have become the key issue to the development of hydrogen fuel cell vehicles.Because the hydrogen storage devices subjects to the high pressure,how to avoid failure and how to store hydrogen cylinder in the design is of important to store hydrogen cylinders to achieve better protection when it is hit from external load impact At the same time,China's hydrogen fuel cell vehicles starts lately,so far there is not a complete safety evaluation method for the hydrogen fuel cell vehicles.Firstly,this thesis analyzes the impact and development of the hydrogen storage cylinder on the fuel cell vehicle.The research background and significance as well as relevant research progress at home and abroad were introduced.The nonlinear finite element theory and relevant algorithms used in vehicle collision simulation analysis were discussed.On the vehicle and the finite element model of the gas cylinders and related parts were set up.The processing model and cell division,the validity of the model is proved by finite element method and the grid sensitivity.By selecting the reasonable parameters,it makes the simulation results meet the accuracy requirement.Secondly,Multiple collision conditions were studied.Compared with standard fuel automobile structure,the results show that the gas cylinder increases the rigidity of the fuel cell vehicles.The deformation of the car body in collision is reduced,but the peak acceleration of the crew compartment is bigger.The crew capsule risk increases when the test was performed on the vehicle.It needs to set up the dummy model or the crew compartment monitoring tostrengthen to study collision cases occupant protection.By comparing different collision angles and different collision bias degrees,it shows that the 100% rear rear-end rear-end is the most dangerous condition in all the study conditions.The acceleration of the vehicle and crew cabin fluctuates greatly with a higher peak acceleration.The 30° rear-ending cylinder has the most complex force,and both ends of the cylinder have great stress.On the side where the 25% offset collision is impacted,the cabin acceleration is large,and the risk is high.The rotates of the cylinder is over 27°.The stress of the side impact cylinder head is large,and the invasion speed exceeds the national standard.Therefore,it is recommended to select 100% rear-end collision,30° rear-end collision,25% bias collision and side collision as test conditions in the vehicle collision test,and to monitor the stress change and relative displacement of the cylinder barrel body and both ends of the head,as well as the collision intrusion at the side of the body and the change of the crew cabin acceleration.And then,the thesis points out that in the process of vehicle design,the buffer design should be carried out between the passenger compartment and the gas cylinder to reduce the threat of the gas cylinder to the crew compartment.To reduce the accumulation of energy in the cylinder,the energy absorption design should be carried out on the parts carrying the cylinder.The restraint belt and the joint between the restraint belt and the vehicle should be designed to ensure that it will not break in the collision.Special design should be carried out to minimize the intrusion of side impact on the middle and rear wing plates,or buffer device should be designed for the cylinder head.Lastly,the constraint device is optimized and improved.The improved model is calculated and analyzed.According to the discussion and analysis,it is found that strengthening the material and structure of the restraint belt can reduce the stress of the cylinder,and reduce the contact force between the cylinder and other parts,and improve the safety of the cylinder.By increasing the number of restraint bands,the stress and relative displacement of the cylinder can be reduced effectively.The placement of the gas cylinder is studied and compared with three common placements.It is found that when the gas cylinder is placed under the rear seat,it is the safest.The A and B protection frame is designed,which can better limit the relative displacement of the cylinder.The peak stress of the cylinder is also lower under the protection of the frame.