Improving Crashworthiness of Railroad Rolling Stocks With New Generation Shock Energy Absorbers

2011 ◽  
Author(s):  
Basant K. Parida ◽  
Xudong Xin ◽  
Abdullatif K. Zaouk ◽  
S. K. Punwani
Keyword(s):  
Energy Absorption ◽  
High Energy ◽  
Dynamic Force ◽  
Fe Model ◽  
Practical Applications ◽  
High Deformation ◽  
Shock Energy ◽  
Force Magnitude ◽  
High Energy Absorption ◽  
Energy Absorbers

This paper describes the results of quasi-static and dynamic tests of a new shock energy absorber (SEA) capable of high energy absorption while limiting peak dynamic force magnitude in the event of an impact or collision. The SEA utilizes the unique reversible phase transition behavior of Ultra High Molecular Weight Poly-Ethylene (UHMWPE) material under pressure. A prototype drop hammer test confirmed the device’s high energy absorption as well as high damping capabilities at a relatively high deformation rate. The results of the test were used to calibrate a finite element (FE) model that enabled scalability of the SEA for practical applications. Preliminary design and FE simulations were made under a Federal Railroad Administration (FRA) sponsored program toward using a set of SEA as a part of a crash energy management (CEM) system to improve locomotive crashworthiness. The main objective of the program was to prevent locomotive override in the event of an inline collision with a hopper car consist at a closing speed of 30 mph. The FE model, without CEM, was validated to a previously performed full-scale locomotive crashworthiness test at Transportation Technology Center, Inc. (TTCI), Pueblo. The FE simulation results with added CEM system showed successful prevention of locomotive override up to 32.1 mph collision speed. Further scope of using suitably tailored SEA units as buffers to the ends of passenger coaches and tank cars with the objective of enhancing their crashworthiness is discussed.

Corrugated Tube Inversion for Energy Absorption

2015 ◽  
Author(s):  
Yang Li ◽  
Zhong You
Keyword(s):  
Energy Absorption ◽  
Circular Tube ◽  
Reaction Force ◽  
High Energy ◽  
Corrugated Tube ◽  
Very High Energy ◽  
Lubricated Contact ◽  
High Energy Absorption ◽  
Energy Absorbers ◽  
Very High

Thin-walled tubes subjected to axial crushing have been extensively used as energy absorbers in transportation system. It has been known for some time that inversion of a circular tube can have very high energy absorption capability and a stable reaction force. However, its inversing mechanism is rather unstable, and it requires a lubricated contact surface, both of which largely hinder its wide application. This paper proposes to use corrugated tube for inversion, which provides a stable inversing mechanism and no requirement for lubricated contact. Furthermore to the improvement of inversing stability, a comparison between inversion of corrugated tube and buckling of circular tube has been done. It shows that the inversion of the corrugated tube has longer stroke, higher energy absorption capability and better load uniformity than that of buckling of circular tube.

scholarly journals Comparative study on destructive performance and energy absorption of aluminum tube by simulation and experiment

2020 ◽  
Vol 12 (5) ◽  
pp. 168781402092413
Author(s):  
Lai Hu ◽  
Jun Zha ◽  
Yaolong Chen
Keyword(s):  
Comparative Study ◽  
Energy Absorption ◽  
Simulation Analysis ◽  
High Energy ◽  
Low Energy ◽  
Tube Length ◽  
Thin Wall ◽  
Span Length ◽  
Aluminum Tube ◽  
High Energy Absorption

This study conducted an investigation on transverse quasi-static three-point loading on a circular aluminum tube and its characteristic plastic failure and energy-absorption behaviors. The thin wall thickness of the aluminum tube, the various diameter and thickness ratios ( D/ t) of the tube, and the tube length are important control parameters. Experimental data for different span length and thickness ratios of the tube were characterized and correlated to its plastic collapse behavior. A simulation model by computational analysis using ANSYS was also conducted as a comparative study. The results of the study found that transverse three-point bend loading (ASTM F290) of a circular aluminum tube underwent different stages of deformation, from initial pure crumpling to crumpling and bending, and finally, structural rupture. The results of master curve analysis found that regions of high energy absorption and low energy absorption can be classified with respect to the characteristic tubular deformation. High energy absorption deformation is correlated with a short span length and higher D/ t ratio, and vice versa for low energy absorption deformation of the circular aluminum tube. Simulation analysis also predicted similar characteristic trends of deformation behavior in the experiment, with a less than 3% average coefficient of variation.

scholarly journals Bending Response and Energy Absorption of Closed-Hat-Section Beams

2016 ◽  
Vol 10 (11) ◽  
pp. 225
Author(s):  
Hafizan Hashim ◽  
Amir Radzi Ab Ghani ◽  
Wahyu Kuntjoro
Keyword(s):  
Energy Absorption ◽  
Plate Thickness ◽  
Point Of View ◽  
Critical Parameters ◽  
Research Report ◽  
Experimental Point ◽  
Fe Model ◽  
Research Information ◽  
Foam Filling ◽  
Energy Absorbers

Many articles on bending collapse but not limited to closed-hat-section beams have been reported mainly from experimental point of view but less in simulation-based approach. Detailed investigation on critical parameters of closed-hat-section beams to examine their energy absorption capability is also less found in the literature. This paper presents the procedure for development and validation of a finite element (FE) model of a closed-hat-section beam under quasi static three-point bending using an explicit nonlinear FE technique. Developed FE models were validated through comparison with existing and present experiment results. Firstly, the existing models were rebulit via present modeling technique using informations provided in the relevant research report. Simulation results of rebuilt model were compared with existing results for verification and validation. Next, to further validate the present model, actual physical experiment replicating the FE model was set up for comparison of results. Validated models were then used in parametric studies in order to investigate the effect of some critical parameters such as plate thickness, flange and web width, and foam filler. Results show that the wall thickness, web width, and filler have direct effect on bending stiffness. Foam filling indicated significant enhancement on the crush and energy absorption of closed-hat-section beams. This study provides detail procedures and research information which will facilitate improvisation of current design as well as the design of foam filled closed-hat-section beams as energy absorbers in impact applications.

Design of Fiber-Reinforced Composite Tubes as Energy Absorption Element

2009 ◽  
Author(s):  
Y. Yang ◽  
S. Terada ◽  
M. Okano ◽  
A. Nakai ◽  
H. Hamada
Keyword(s):  
Energy Absorption ◽  
High Energy ◽  
Fiber Reinforced ◽  
Inertia Moment ◽  
Reinforced Composite ◽  
Bending Behavior ◽  
High Energy Absorption ◽  
Energy Absorbing ◽  
Frp Tubes ◽  
Two Sides

As an energy absorption member, fiber-reinforced composites (FRPs) are more favorable because they are light in weight and possess better energy absorption capabilities as compared to their metal counterparts. However, the energy absorbing mechanisms of FRP are complicated owning to the multi-micro fractures. Therefore, in this study, the designs of FRP tubes were carried out with considerations directed at the energy absorbing mechanisms. Two methods based on the design of the energy absorbed by bending of the fronds (Ubend) and the energy absorbed by fiber fractures (Uff) are concentrated. Here the bending behavior of frond can be considered as the bending beam by an external force. And it is found that Ubend is affected directly by the inertia moment I, which is affect by the geometry. Therefore, FRP tubes were fabricated to have a geometry combined with a bigger I. Additional, in order to get more fiber fractures to get an increased Uff, the design of bending stress, σ, was carried out. FRP tubes bending towards one side only rather than two sides are proposed to get bending fronds with a double thicker thickness, which in turn led to high stresses, many fiber fractures and high energy absorption.

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