DESIGN AND OPTIMIZATION OF FRONT-END STRUCTURE WITH INTEGRATED ENERGY ABSORPTION FOR RAILWAY VEHICLES

As the main energy absorbing area of a railway vehicle, the front-end structure is critical to reduce the collapse of the passenger area and increase the safety of the vehicle in case of collision. In this paper, a front-end structure with integrated energy absorbing is introduced in detail as well as the iteration process. The front-end structure is mainly composed of anti-climber, collision posts, corner posts and four kinds of crush elements including center crush elements, side crush elements, interior crush elements and head girders. The shape, dimension, position, connection and material of those components are optimized multiple times based on the finite element analysis results of various load cases. The finalized structure can provide progressive controlled collapse with energy absorbing capacity of 1.22MJ and impact force less than 4450kN. At the same time, it is capable to withstand a static longitudinal load of 1224kN and vertical load of 334kN. To validate the design and analysis, the front-end structure is manufactured and tested under impact. The crash velocity, deformation and impact force show great agreement between the simulations and test results. From the design and optimization of this front end structure, it is concluded that placing the crush elements behind the collision post is beneficial for static strength design, the energy absorbing capability can be largely increased without taking additional space by using interior crush element and the geometry of the head girders plays an critical role in balancing the force distribution and providing stable crush performance.