Research On Crashworthiness Of Power Centralized EMU

With the increase of railway running mileage and speed,people take more and more attention on the safety of railway vehicle,so it's very important to study the passive safety of railway vehicle during the design of rail vehicle structure.Based on the research methods and achievements of rail vehicle's passive safety protection technology at home and abroad,in this paper,taking explicit finite element numerical simulation methods to study the crashworthiness of railway vehicle.In this paper,the theory of explicit finite element method of locomotive vehicle is expatiated and the physical principle of the problem is taken from the basic control equation of the collision problem.The concept and control method of explicit integration time step size,the contact algorithm theory and the approach for dealing with common problems such as negative sliding interface energy are introduced emphatically.The basic energy-absorbing element is an important part of the anti-collision energy absorption system of the locomotive vehicle.The thin-walled metal pipe structure with high specific energy absorption and low initial peak load can improve the collision resistance of the vehicle.In this paper,a multi-layer nested thin-walled energy absorbing structure is proposed based on the study of a large number of basic energy-absorbing elements,and its anti-collision performance is simulated in explicit finite element software LS-DYNA.Furthermore,its energy absorption characteristic index is compared with the traditional thin-walled energy absorption structure under the same conditions and its superiority in collision resistance performance is pointed out.Establishing a reasonable and effective finite element model for train collision simulation is the most basic and critical step in the process of calculating the collision resistance performance of the train by numerical simulation method.In this paper,taking a power centralized EMU for research,establishing an accurate and reliable vehicle collision finite element model though considering the actual connection relation and working principle of the body structure,couplers and buffers,anti-climbing device and bogie in the pre-processing software HyperMesh under the princple of not only considering the computational efficiency but also the computational accuracy.The impact resistance of the power centralized EMU is calculated and analyzed under six typical collision scenarios determined according to EN15227 and train running status.LS-DYNA is used to simulate the crashworthiness of the power centralized EMU in specified conditions.The effect of the main buffer energy absorbing components such as the couplers and buffers and the anti-climbing device is analyzed,and the rationality and accuracy of the finite element model of the train are also verified.