Papers by Keyword: Energy Absorber

Abstract: Energy absorption devices are being used to protect structures from severe damages and reduce injury to occupants during accidents. The integrated characteristics of crash absorption devices can be classified as high energy absorption capacity, light-weight, and cost-effective. One of the thin-walled structures which has drawn the attention of scientists is corrugated tube structure. In this paper, the effect of corrugation geometry on the crushing parameters of an aluminum corrugated tube is investigated. In this regard, different elliptical corrugation shapes were deemed and the compression response was numerically evaluated under lateral quasi-static loading. Finally, the crashworthiness parameters were extracted and compared to determine the influence of corrugation shape on the crashworthy response. Our results showed that using vertical elliptical corrugation decrease the densification point. Moreover, there is a gradual enhancement of mean crushing load by moving from the horizontal elliptical corrugations to the vertical ones. Also, by modifying of corrugation shape, the stress variation pattern changes, significantly.

Abstract: Aseismic design of modern structures imposes a new requirement on structural engineers. Structural systems should withstand even very huge earthquakes. This goal cannot be achieved by standard design methods applying a linear elastic approach. An advanced aseismic design applies energy dissipating anti-seismic devices. During seismic event, these devices are exposed to a large plastic strain. The code EN 15129 is the standard on anti-seismic devices applicable in Europe. Mentioned standard defines a special material requirement imposed on devices working as energy absorbers. Material verification is possible only experimentally. In compliance with the instructions contained in the code EN15129, several cyclic tests of the materials S235 and DD11 have been used. Evaluation of the previous research and the current test results have proved that structural steel S235 is not applicable to the anti-seismic devices. As an alternative, steel DD11 has been suggested for this application. The test results have shown that the steel DD11 is applicable in specified range of target strain amplitudes.

Abstract: By analyzing advantages and disadvantages of the existing energy absorbers, carbon fiber composite and regular hexagon honeycomb structure were chosen as material and topological structure respectively to make a big-bearing, lightweight energy absorber. Preparation method of carbon fiber composite honeycomb energy absorber was studied, which was applied to manufacture some specimens,and it is feasible because of the specimens good consistency and regularity. Quasi-static compression tests of the specimens were carried out, and then the related parameters of energy-absorbing characteristics were calculated. The results show that the carbon fiber composite honeycomb energy absorber has excellent energy-absorbing characteristics.

Abstract: This paper deals with the development of a deformation element designed to be used in transportation industry. The aim is to develop a design of thermoplastic composite that begins to warp under a considerable impact loading and thus ensures a high energy absorption. This is accomplished using several modes of deformation. Fiber fracture and delamination of the composite layers can be counted among the most important ones. The shape of the deformation element was designed to utilize the advantages of its thermoplastic matrix when creating the shape of the composite plate as well as when joining the plates together (welding, bonding).

Abstract: As people paying more attention to the automotive safety performance, the car manufacturers bring steady improvement in the pedestrian protection of vehicle. This paper contains a new type of energy absorber used for lower leg-form impact by concept design method through Madymo (MAthematical DYnamic MOdel). Finally it is validated by full FE analysis. This new type of energy absorber can improve the performance of lower leg-form impact; also provide a design reference for vehicle's frontal system design.

Abstract: This paper presents the study of nested rings crushed laterally between rigid platens at 2 different velocities. In this investigation two different types of nested ring configurations are analysed: (A) In-Plane; where three rings of varying diameter are placed within each other and their axes are parallel. (B) Out of-Plane; where the rings have a 90 degree orientation. Material used was cold finished, drawn over mandrel (DIN 2393 ST 37-2) and is referred throughout the paper as mild steel. The Cowper-Symonds relation was used to predict the dynamic yield stress of the rings and this was included in the FE material model. The results obtained from experiments were compared to that of finite element method using the software package Ansys. Discussion is made on the post – collapse behaviour of these systems. It was found that the Out of-Plane ring system exhibited a more desirable force-deflection response due to its 90 degree orientation.

Abstract: 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.