Ign Wiratmaja Puja

Numerical and Experimental Study on Railway Impact Energy Absorption Using Tube External Inversion Mechanism at Real Scale

Impact energy and deceleration at a certain time are the most influenced factor to passenger’s safety when collision between railway vehicles occurred. In this paper, forced external inversion mechanism is considered as impact energy absorber. This mechanism is selected due to its constant inversion load along uniform tube [5] and the impact force is reduced because of its inertia effect [7]. Material used as energy absorber is mild steel. Numerical analysis using finite element method is utilized to study the energy absorption capacity and deceleration characteristic of tube external inversion mechanism for complex transient problem of collision. The real scale experimental study is used to validate the numerical analysis by crashing a moving vehicle to static train series where the impact energy absorber module using external inversion mechanism is attached in the tip of static train series. Characteristic that consider in numerical and experimental study are deformation and contact force. The deformation differences between numerical and experimental study are under 9%. Whereas for contact force, the experimental result of contact force disposed under 8% of numerical result for velocity of moving train at 10 and 15 km/h.

Newly Designed Adhesive Joint for Torque Loaded Tube

Adhesive joint is commonly applied to CFRP/GFRP composite tube, however, its failure rate is still high and this will limit the use of composite tube for industrial purpose. The literature study showed that the stress distribution at the joint, when loaded, is not evenly distributed and creates stress concentration at the edges. Attempts have been made by researchers to improve the joint design so that the stress would be more evenly distributed and minimize stress concentration, however, the improvement has been very limited. In this work, a comprehensive parameter study has been performed to observe the properties of adhesive joint of torque loaded tube. Based on the observation, a new type of adhesive joint is proposed which successfully reduces the stress concentration along the joint during torque loading. The analysis was performed using finite element method.

Crash Zone Development for Railway Vehicle

This paper considers crash zone development for railway vehicle to improve it’s crashworthiness characteristics. The principle of modification is by weakening the crash zone area and strengthening the passenger area. Thus the huge impact energy during collision will be absorbed by crash zone area so that it will maintain the structural integrity of the passengers. There are two type of modifications proposed in this study. The first modification is conducted by weakening the end-under-frame section and strengthening the middle-under-frame section. These modification shows deformation characteristics improvement where the passenger area structure are not suffered from buckling and plastic deformation as expected. The second type of modification is full modification on end-under-frame. These modifications give better improvement on the deformation and energy absorption characteristics, however in the practical application, this will be more expensive option.

The Structural Impact Characteristics of Indonesian Railway Vehicle

The Indonesian railway transportation has adventages in term of capacity, efficiency, trafic, and safety compared to the other types of land transportations. At present, the Indonesian Railway Company has 519 locomotives, and 1643 passenger cars, that transport about 184 million man-trip each year[1,2]. Unfortunately, the rate of train collisions in Indonesian railway system was very high. In the last ten years, 2352 train accidents have happened which claimed 997 lives and left 2638 people injured. The record shows that 110 of those accidents were train to train collisions[1]. This paper consider the structural impact behavior of Indonesian passenger railway car subject to collision forces. This characteristic is very important parameter for passenger protection during the course of collision[3-5]. The vehicle structure should be able to absorb the huge impact energy or impact force to ensure the passenger safety[6-9]. The impact energy of cars-train is evaluated using the principle of multibody dynamics[10,11]. The vehicle structure under impact load is analyzed using the finite element method. The principal of symmetry is adopted, so the collision scene could be simulated as collision between the vehicle with a rigid wall. The analysis result shows that the structure is collapse at the passenger area (saloon) which is in agreement with the real collision. Modification is proposed to protect the passenger area by introducing crush zone area and impact energy absorber.