Impact Response of Thin-Walled Tubes: A Prospective Review

2012 ◽  
Vol 165 ◽  
pp. 130-134 ◽  
Author(s):  
Fauziah Mat ◽  
K. Azwan Ismail ◽  
S. Yaacob ◽  
O. Inayatullah

Thin-walled structures have been widely used in various structural applications asimpact energy absorbing devices. During an impact situation, thin-walled tubesdemonstrate excellent capability in absorbing greater energy through plastic deformation. In this paper, a review of thin-walled tubes as collapsible energy absorbers is presented.As a mean of improving the impact energy absorption of thin-walled tubes, the influence of geometrical parameters such as length, diameter and wall thickness on the response of thin-walled tubes under compression axial loading are briefly discussed. Several design improvements proposed by previous researchers are also presented. The scope of this review is mainly focus on axial deformation under quasi-static and dynamic compressive loading. Other deformations, such as lateral indentation, inversion and splitting are considered beyond the scope of this paper. This review is intended to assist the future development of thin-walled tubes as efficient energy absorbing elements.

2018 ◽  
Vol 12 (1) ◽  
pp. 54-59 ◽  
Author(s):  
Maria Kotełko ◽  
Mirosław Ferdynus ◽  
Jacek Jankowski

AbstractIn the paper the study of different crashworthiness indicators used to evaluate energy absorbing effectiveness of thin-walled energy absorbers is presented. Several different indicators are used to assess an effectiveness of two types of absorbing structures, namely thin-walled prismatic column with flaws and thin-walled prismatic frustum (hollow or foam filled) in both cases subjected to axial compressive impact load. The indicators are calculated for different materials and different geometrical parameters. The problem of selection of the most appropriate and general indicators is discussed.


2019 ◽  
Vol 8 (4) ◽  
pp. 3911-3915 ◽  

To mitigate the impact forces in crash events, thin-walled tubular elements are employed as an energy absorbing attenuators in frontal part of the automotive vehicles. To develop more progressive deformation modes, at the initial period, and to absorb more impact energy at the final period of crash, it is significant to enhance the crashworthiness performance of the tube by modifying its geometrical parameters. Multi-cell tubular structures have recognized to own superior impact energy absorbing ability and lightweight effect in the modern automotive vehicles. This research article examines the deformation behaviour of thin walled aluminum alloy multi-cell tube with different stiffeners exposed to axial impact loading using numerical simulation. Nonlinear impact simulations were performed on multi-cell tubes using finite element ABAQUS/CAE explicit code. From the overall results obtained, the deformation behaviour of multi-cell tubes was compared. Furthermore, hexagonal tubes with stiffeners were retained as most prominent for better energy dissipation. This type of tube was found to be most efficient type to enhance the crashworthiness performance during axial impact.


2013 ◽  
Vol 371 ◽  
pp. 715-720
Author(s):  
Vlad Andrei Ciubotariu

This paper investigates the crashing behaviour of thin-walled structures having various cross-sections subject of dynamic axial loading. The aim is to understand the collapse mode formation, energy absorption behaviour and progressive buckling phenomenon regarding TWB thin-walled structures. Three different cross-section shapes were used for this study as it follows: circular, hexagonal, rectangular. In the fabrication process of the structure itself, homogeneous materials are often used but an attractive solution for the automotive companies is materialized by the use of tailor welded blanks. In this paper, the impact crashing procedure was performed using a custom impact setup and the non-linear finite element platform LS-Dyna V4.0. After these analyses it can be concluded that a correlation between the number of folds and the mean load and the weld line could be made. The number of folds tends to increase as the mean load also increases. The weld line has an important role in the collapse mode formation and the values of the mean load.


Author(s):  
Fengxiang Xu ◽  
Suo Zhang ◽  
Kunying Wu

Thin-walled structures with graded property have been paid more attention in recent years due to their significant balance between lightweight and crashworthiness. However, few studies have been focused on energy absorption capacity of thin-walled conical tubes with graded diameters. In this paper, the thin-walled conical aluminum tubes with nonlinearly-graded diameters are introduced and their corresponding crashing characteristics are performed. The diameters are assumed to nonlinearly vary according to a power-law distribution function primarily determined by a graded exponent n. It is found that the total weight of thin-walled conical tubes decreases with the increasing of the gradient exponent. The energy-absorbed performances such as specific energy absorption, initial peak crashing force, and mean crashing force of those graded tubular structures are numerically analyzed. And then the effects of various geometric parameters such as the gradient exponent, deformation distance, and diameter range on crashing behaviors are further evaluated. It is observed that those parameters especially the gradient exponent has significantly obvious effects on crashworthiness of the proposed nonlinearly graded tubes. It is also noted that the straight conical structure with gradient n = 1.0 may not show the best energy absorption characteristics compared with other gradients. The work could provide valuable information for effective design of thin-walled energy-absorbing structures with variable geometrical parameters.


Author(s):  
Jianxun Du ◽  
Peng Hao ◽  
Kai Liu ◽  
Lin’an Li ◽  
Mabao Liu

With the increasing damage of lives and properties caused by impact accidents, thin-walled tubes have been widely employed to make energy-absorbing structures in the field of automotive engineering due to their lightweight and energy absorption ability. In this work, we proposed three kinds of thin-walled bio-mimetic tubes inspired by horsetail plants and investigated the energy absorption abilities of the above structures with hollow columns under impact loading by means of the finite-element method. The effect of three factors, including column diameter, wall thickness, and impact angle, on the energy absorption characteristics of the bio-mimetic structure, is discussed. The primary outcome of this research is a design method for the use of thin-walled multi-cell tubes for an energy absorption device where impact loading is expected. It was also found that the energy absorption performances of the hexagonal structures are better than that of the triangular and quadrilateral ones. Moreover, the results revealed that the absorbed energy by thin-walled bio-mimetic structures shows more dependence on the impact angle than on the wall thickness of the tube.


Author(s):  
Jianxun Du ◽  
Peng Hao ◽  
Mabao Liu ◽  
Rui Xue ◽  
Lin’an Li

Because of the advantages of light weight, small size, and good maneuverability, the bio-inspired micro aerial vehicle has a wide range of application prospects and development potential in military and civil areas, and has become one of the research hotspots in the future aviation field. The beetle’s elytra possess high strength and provide the protection of the abdomen while being functional to guarantee its flight performance. In this study, the internal microstructure of beetle’s elytra was observed by scanning electron microscope (SEM), and a variety of bionic thin-walled structures were proposed and modelled. The energy absorption characteristics and protective performance of different configurations of thin-walled structures with hollow columns under impact loading was analyzed by finite element method. The parameter study was carried out to show the influence of the velocity of impactor, the impact angle of the impactor and the wall thickness of honeycomb structure. This study provides an important inspiration for the design of the protective structure of the micro aerial vehicle.


Author(s):  
Sean Jenson ◽  
Muhammad Ali ◽  
Khairul Alam

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.


Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4742
Author(s):  
Tomasz Kopecki ◽  
Przemysław Mazurek ◽  
Łukasz Święch

This study presents the results of experimental research and numerical calculations regarding models of a typical torsion box fragment, which is a common thin-walled load-bearing structure used in aviation technology. A fragment of this structure corresponding to the spar wall was made using 3D printing. The examined system was subjected to twisting and underwent post-critical deformation. The research was aimed at determining the influence of the printing direction of the structure’s individual layers on the system stiffness. The experimental phase was supplemented by nonlinear numerical analyses of the models of the studied systems, taking into account the details of the structure mapping using the laminate concept. The purpose of the calculations was to determine the usefulness of the adopted method for modeling the examined structures by assessing the compliance of numerical solutions with the results of the experiment.


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