A design approach for a crash energy management (CEM) system for a N13-type railway passenger car used by the Turkish State Railway Company is developed in this paper. The components of the CEM system are honeycomb-structured boxes, primary energy absorbers, shear bolts, a sliding sill mechanism and a fixed sill mechanism that are located in the passenger-free space at the end of the passenger car. In order to investigate the benefits provided by the CEM system, a full-scale railway passenger car collision with a rigid wall is simulated by using dynamic/explicit finite element (FE) methods. The crushing force, secondary impact velocity, acceleration and velocity curves, and deformation modes are computed to allow a comparison of the crashworthiness performance of a passenger car equipped with the proposed CEM system with that of a conventional passenger car. Comparisons of FE analysis results show that a passenger car incorporating the CEM system has a superior crashworthiness performance to that of the conventional passenger car.
This paper presents a study on the development of a side buffer to absorb the impact energy of colliding railcars. Buffers are essential elements for improving the traveling comfort of passengers and extending the service life of a wagon chassis. In designing the buffer's energy absorption characteristics, a combination of a hydraulic damper and a stack of disc springs (Belleville springs) were utilized. Disc springs have nonlinear load-deflection characteristics; by stacking them in series and parallel arrangements, the desired load-deflection characteristics can be achieved. The finite element method was employed to evaluate the performance of the designed buffer in terms of force-stroke and kinetic, strain, and viscous energies for 5, 7, and 9 km/h impact velocities. Simulation results proved that the designed buffer ensures the requirements of EN 15551 easily for various collision speeds. Low level of acceleration values and small peak collision forces proved that the proposed buffer has superior performance in comparison with the existing buffers in service by improving the shock absorption and crashworthiness features of railcars.
Elastomers, due to their excellent damping and energy absorption characteristics and low cost are used extensively in automobile industry to isolate the structures from vibration and shock loads. In this study, it was aimed to analyze the damping performance of an elastomer buffer embedded in the suspension of an automobile. To reach to this aim, vibration simulation of an automobile suspension model was conducted by using a nonlinear explicit finite element code, Abaqus. In order to simulate the damping behavior of elastomer buffer, the hyperelastic and linear viscoelastic material models were used together. The numerical model was validated with results of exact solution method in terms of transmissibility ratio and phase shift in a wide range of input excitation frequencies. Good agreement was observed between the exact solution and finite element results, which indicated that finite element model was sufficiently accurate. To examine the damping performance of the buffer, the displacement time history curves were extracted for suspension with and without buffer under the sinusoidal base excitations. The vibrating motions of suspension for both conditions were compared. The comparison results prove that the elastomer buffer is effective in improvement of damping performance of suspension. It reduces the amplitude of vibration and oscillation time of sprung mass remarkable in excitation frequencies around and over the natural frequency of the system.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.