Railway Engineering

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Browsing Railway Engineering by Subject "Abaqus software"

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    Improvement of a Locomotive Front End to Reduce Overriding Effect Based on Impact Scenario.
    (Addis Ababa University, 2021-08) Faraja, Nyangassa; Daniel, Tilahun (PhD); Tollosa, Debrie (Mr.)
    The locomotive crash box is an energy-absorbing device that reproduces a crash sound effect during locomotive head-on collisions. Addis Ababa- Djibouti railway is a single-track railway mostly significant head-to-head collisions. Satisfactory achievement of the energy-absorbing crash box arises in weaker destruction to a locomotive and other parts with cheaper restoration price. Customers blame the manufacture that crash boxes are easy to damage although the collision was slow. Passengers are dead and fully damaged of locomotives because of a less energy absorption capability of an impacting crash box. The material of the crash box needs to examine to realize the replacement material that can upgrade the crashworthiness, also have stability. The aim is to improve safety for the passengers and drivers of railway vehicles by improving the weakness of the existing locomotive crash box which is very important during the collision. The objective of this improvement is to select proper material which absorbs more impact energy in such a way that crush zones that are deformable in a defined manner convert this energy into deformation energy. In this project, the Finite Element Method is requested to prototype the crash box structure and material of the crash box. All models are modeled by using CAD software such as SOLID WORKS. Simulation using finite element analysis Software such as ABAQUS was carried out. Modeling the locomotive with crash box and analyzed the structure using ABAQUS/CAE on the exact Steel, Aluminum, and Composite materials (Carbon Fiber). Predicted the time history of the impact process such as load, energy, velocity, and deflection. To measure the energy absorbed by the materials. To predict the energy absorption capacity of the materials. To improve materials by proper material selection and propose suitable material for the locomotive crash box. The selection of suitable material is after compared the Finite Element Analysis results of the conventional materials which are (steel, aluminum) and composite materials (carbon fiber) for the crashworthiness. The study is performed using ABAQUS software to design the locomotive crash box made from steel, aluminum, and carbon fiber and the von misses’ stress, deformation, and energy absorption are evaluated by the use of Finite Element Analysis to determine the impact cases. Lightweight composite materials (carbon fiber) provide opportunities for reducing locomotive weight and other advantages compared to steel and aluminum for a locomotive crash box. The result was shown to be the best when employing carbon fiber material for locomotive crash boxes. From ABAQUS optimization the energy absorption for the steel crash box is 10 KN-M, aluminum crash box 12.5 KN-M and carbon fiber crash box is 13.375 KN-M. Von misses stress for steel crash box is 1538 mpa, aluminum crash box 980.5 mpa, and carbon fiber crash box 682.6 mpa. Deformation for steel crash box is 11.5 mm, aluminum crash box 5.3 mm and carbon fiber crash box is 2 mm. Results conclude that using carbon fiber material for the crash box can reduce deformation and stresses force during a collision of locomotives also has the highest value for energy absorption. It is recommended as a better approach to replace the metallic locomotive crash box.