Novel Design of Impact Attenuator for an 'Eco Challenge' Car

2012 ◽  
Vol 165 ◽  
pp. 237-241 ◽  
Author(s):  
Amir Radzi Ab Ghani ◽  
Ramlan Kasiran ◽  
Mohd Shahriman Adenan ◽  
Mohd Haniff Mat ◽  
Rizal Effendy Mohd Nasir ◽  
...  
Keyword(s):  
Energy Absorption ◽  
Impact Energy ◽  
High Energy ◽  
Absorption Capacity ◽  
Flat Plates ◽  
Final Design ◽  
High Energy Absorption ◽  
Energy Absorbing ◽  
Long Stroke ◽  
The Impact

Thin-walled metallic tubular structures are generally used as impact energy absorber in automotive structures due to their ease of fabrication and installation, high energy absorption capacity and long stroke. However, unlike a normal passenger car where the impact energy can be distributed throughout the whole structure, the impact energy absorbing system of an Eco-Challenge car is confined within a limited space on the front bulkhead. The challenge is to develop an impact attenuator system that can effectively absorb the impact energy within the given space and fulfil the specified rate of deceleration. This new design utilized the standard Aluminium 6063 circular tubes, cut and welded into specific configurations i.e. stacked toroidal tubes with central axial tube sandwiched between two flat plates. Two configurations were investigated; circular and square toroids. Explicit non-linear FEA software was used to determine the impact response i.e. energy absorption, impact force and rate of deceleration. Both configurations showed promising results but the configuration that can be readily fabricated was chosen as the final design.

Impact Response of Circular Tube with Concentric Plunger

2013 ◽  
Vol 275-277 ◽  
pp. 792-798
Author(s):  
Amir Radzi Ab Ghani ◽  
Hafizi Lukman ◽  
Hafizan Hashim
Keyword(s):  
Energy Absorption ◽  
Circular Tube ◽  
High Energy ◽  
Absorption Capacity ◽  
Peak Force ◽  
Impact Response ◽  
Impact Performance ◽  
High Energy Absorption ◽  
The Impact ◽  
Initial Peak

Thin-walled tubes are generally used as impact energy absorber in various application due to their ease of fabrication and installation, high energy absorption capacity and long stroke. However, the main drawback of plain tube is the high initial peak force. A concentric plunger in the form of tapered block is proposed to overcome this shortcoming while at the same time, improving the impact performance. Static and dynamic axial crushing were performed to determine the initial peak force (IPF), crush force efficiency (CFE) and specific energy absorption (SEA) for the concentric plunger with various taper angles. It was found that the concentric plunger affected the tube impact response. Comparison with plain circular tube was carried out and it was found that the concentric plunger improved the impact response of the tube especially in term of initial peak force.

scholarly journals Effect of Fiber Mat Density and Crushing Mechanism on the Energy Absorption Capacity of GFRP Crashworthy Tubes

2019 ◽  
Vol 8 (9S3) ◽  
pp. 297-301 ◽  
Keyword(s):  
Energy Absorption ◽  
Deformation Mechanism ◽  
Theoretical Calculations ◽  
Peak Load ◽  
High Energy ◽  
Constant Load ◽  
Absorption Capacity ◽  
Energy Absorption Capacity ◽  
High Energy Absorption ◽  
Energy Absorbing

The aim of this study is to examine the effect of fiber mat’s density and deformation mechanism of tubes with and without die compression. In this study a new mode of deformation mechanism of density graded GFRP circular tube is examined when they are subjected to axial compression on to a die and without die to examine its energy absorbing capacity. Theoretical calculations were made to predict the crushing stress of different specimens. It is observed that increasing density of fiber increases energy absorption value but decreases the specific energy absorption and the die could trigger progressive crushing additionally decreasing peak load. Here the compressed tube wall is compelled to be deformed towards the end of compression die with a little range of bending curvature which was forced by the radius of the die at high crushing stress and the major part of the deformation takes place at a nearly constant load, which leads to high energy absorption capacity. Comparison between theoretical prediction values by derived equations and the experimental results shows good correlation.

Composite Core Cross Tube Crushing Analysis

2020 ◽  
Author(s):  
Sean Jenson ◽  
Muhammad Ali ◽  
Khairul Alam
Keyword(s):  
Energy Absorption ◽  
Compressive Loading ◽  
Deformation Mode ◽  
High Energy ◽  
Absorption Capacity ◽  
Functionally Graded ◽  
Layer By Layer ◽  
Thin Walled ◽  
The Cross ◽  
Energy Absorbing

Abstract Thin walled axial members are typically used in automobiles’ side and front chassis to improve crashworthiness of vehicles. Extensive work has been done in exploring energy absorbing characteristics of thin walled structural members under axial compressive loading. The present study is a continuation of the work presented earlier on evaluating the effects of inclusion of functionally graded cellular structures in thin walled members under axial compressive loading. A compact functionally graded composite cellular core was introduced inside a cross tube with side length and wall thickness of 25.4 mm and 3.048 mm, respectively. The parameters governing the energy absorbing characteristics such as deformation or collapsing modes, crushing/ reactive force, plateau stress level, and energy curves, were evaluated. The results showed that the inclusion of composite graded cellular structure increased the energy absorption capacity of the cross tube significantly. The composite graded structure underwent progressive stepwise, layer by layer, crushing mode and provided lateral stability to the cross tube thus delaying local tube wall collapse and promoting large localized folds on the tube’s periphery as compared to highly localized and compact deformation modes that were observed in the empty cross tube under axial compressive loading. The variation in deformation mode resulted in enhanced stiffness of the composite structure, and therefore, high energy absorption by the structure. This aspect has a potential to be exploited to improve the crashworthiness of automobile structures.

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.

scholarly journals Achieving high energy absorption capacity in cellular bulk metallic glasses

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
S. H. Chen ◽  
K. C. Chan ◽  
F. F. Wu ◽  
L. Xia
Keyword(s):  
Energy Absorption ◽  
Metallic Glasses ◽  
Bulk Metallic Glasses ◽  
High Energy ◽  
Absorption Capacity ◽  
Energy Absorption Capacity ◽  
High Energy Absorption

Electrical and microstructural characteristics of ZnO–Bi2O3-based varistors doped with rare-earth oxides

2001 ◽  
Vol 16 (10) ◽  
pp. 2817-2823 ◽  
Author(s):  
Nguyen The Hung ◽  
Nguyen Dinh Quang ◽  
Slavko Bernik
Keyword(s):  
Rare Earth ◽  
Energy Absorption ◽  
Threshold Voltage ◽  
Spinel Phase ◽  
High Energy ◽  
Absorption Capacity ◽  
Rare Earth Oxides ◽  
High Threshold ◽  
Energy Absorption Capacity ◽  
High Energy Absorption

ZnO-based varistor samples with a relatively high Sb2O3 to Bi2O3 ratio of 5 were fired at 1200 °C and found to have a high threshold voltage (VT) of 280 V/mm and a low energy-absorption capacity of 50 J/cm3. The introduction of rare-earth oxides (REO) increased the energy-absorption capacity of Pr6O11- and Nd2O3-doped samples to 110 J/cm3 while their threshold voltage (VT) remained slightly above 300 V/mm. Doping with Pr6O11 and Nd2O3 altered the formation of the spinel phase and significantly changed its particle size and distribution which, as a result, had a positive effect on the energy-absorption capacity of the REO-doped samples. Doping with small amounts of Pr6O11 and Nd2O3 appears to be promising for the preparation of ZnO-based varistors with a high breakdown voltage and a high energy absorption capacity.

Containment and Arrest of Blade Shedding in Gas Turbine Engines Using Novel Dual-Ring Design

2021 ◽  
Author(s):  
Prayers Roy ◽  
Shaker A. Meguid
Keyword(s):  
Energy Absorption ◽  
Impact Damage ◽  
Impact Resistance ◽  
High Energy ◽  
Element Analysis ◽  
Single Ring ◽  
High Energy Absorption ◽  
Interfacial Gap ◽  
The Impact ◽  
Dual Ring

Abstract In this paper, we examine the energy absorption and containment capabilities of a newly proposed dual-ring design accounting for interactions between a released blade and fully bladed fan disk using 3D finite element analysis. The components of this dual-ring design are strategically selected to ensure high energy absorption and high impact resistance, thus leading to reduced damage of the disk and increased safety. Three containment ring designs are examined: (i) conventional single-ring design composed of one of titanium, aluminum or Kevlar, (ii) a newly proposed aluminium-Kevlar dual-ring arrangement, and (iii) dual-ring arrangement with an interfacial gap between them to arrest and contain the released blade and ensure free passage of the trailing blades. The results of our numerical simulations indicate that although the single-ring design resists penetration and contains the released blade within the confines of the disk, it does not remove the released blade from the path of the trailing blades leading to severe damage to the fan disk. On the contrary, our new dual-ring design, which contains an interfacial gap, has potential to successfully arrest the released blade within the confines of the ring and out of the path of the trailing blades. This design significantly can reduce the impact damage to the fan disk and reduces kinetic energy of the released blade to near zero in less than half a rotation of the fan disk.

Effect of Parameter Optimization of Contact Force Models on the Impact Dynamic Responses

1993 ◽  
Author(s):  
H. M. Lankarani ◽  
F. Wu
Keyword(s):  
Energy Absorption ◽  
Contact Force ◽  
Multibody System ◽  
High Energy ◽  
Contact Forces ◽  
Dynamic Responses ◽  
Particle Model ◽  
Force Model ◽  
High Energy Absorption ◽  
The Impact

Abstract Reducing the severity of an impact to a structure or a multibody system is a significant aspect of engineering design. This requires the knowledge of variations of the resulting contact forces and also how these contact forces can be reduced. This paper presents an optimization methodology for the selection of proper parameters in the contact/impact force models so as to minimize the maximum value of the contact force. A two-particle model of an impact between two solids is considered, and then generalized to the impact analysis between two bodies of a multibody system. The concept of effective mass is presented in order to compensate for the effect of joint forces or impulses. The system is reduced to a single degree-of-freedom mass-spring-damper vibro-impact system. A single differential equation of motion in the direction of relative indentation of local contact surfaces is derived. Different contact force models of hysteresis form including linear and nonlinear models are described. An optimization problem is then formulated and solved by using the method of modified feasible direction for constrained minimization. A numerical integrator is used at every design iteration to obtain the system dynamic response for a given set of design variables. The objective function is to minimize the peak acceleration of the system equivalent mass resulting from the contact force. Comparison of the system with optimal parameters and non-optimal one shows that the peak contact force is greatly reduced for the optimal one. Since these parameters reflect the material properties (stiffness and damping) of the impacting bodies or surfaces, suitable materials may then be selected based upon the information provided by this optimization procedure. It is observed that the materials, which have good crashworthiness properties should posses capability of dissipating impact energy both in the forms of permanent indentation and internal damping friction. Based upon the analysis of the impact responses, mechanism of energy dissipation, and the typical force-indentation diagram for the high energy absorption materials obtained from experiments, a new contact force model is proposed which could precisely describe the impact response of high energy-absorption materials.

Material and shape crash-box influence on the evaluation of the impact energy absorption capacity during a vehicle collision

2016 ◽  
Vol 28 (1) ◽  
pp. 67-72 ◽  
Author(s):  
Gabriel Jiga ◽  
Ştefan Stamin ◽  
Gabriela Dinu ◽  
Daniel Vlăsceanu ◽  
Dorina Popovici
Keyword(s):  
Energy Absorption ◽  
Impact Energy ◽  
Absorption Capacity ◽  
Energy Absorption Capacity ◽  
Vehicle Collision ◽  
The Impact

Numerical and Experimental Investigation on Corrugation Geometry for Metallic Tubes under Lateral Loading

2018 ◽  
Vol 916 ◽  
pp. 226-231 ◽  
Author(s):  
Arameh Eyvazian ◽  
Hozhabr Mozafari ◽  
Faris Tarlochan ◽  
Abdel Magid S. Hamouda
Keyword(s):  
Energy Absorption ◽  
Cost Effective ◽  
High Energy ◽  
Absorption Capacity ◽  
Energy Absorption Capacity ◽  
Stress Variation ◽  
Thin Walled Structures ◽  
Corrugated Tube ◽  
High Energy Absorption ◽  
Tube Structure

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.

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