Energy Absorption Characteristics of a Thin-Walled Tube Filled With Carbon Nano Polyurethane Foam and Application in Car Bumper

Author(s):  
D. Tankara ◽  
R. Moradi ◽  
Y. Y. Tay ◽  
H. M. Lankarani

Over the past few decades, much research work has been conducted on the development of advance crashworthy structures to increase the energy absorption of mechanical systems. Thin-walled tubes are primarily used as structural reinforcements and as energy absorbing components. The high-energy absorption characteristics of cellular foams have attracted great attention to further enhance this superior capability. In particular, nanotechnology has been utilized in the development of advanced cellular materials for the automotive and aerospace industry. The primary objective of this study is to conduct a parametric study using experimental and finite element methods to examine and quantify the performances of thin-walled tube when filled with carbon nano particulates. To accomplish this study, compression tests are carried out to obtain the load-deflection curves of the nano-foams when subjected to different weight percentages of carbon nano fibers. Next, the specific energy absorbed and the collapse mechanism of nano foam filled thin-walled tubes are analyzed and compared with the empty ones. Finally, an illustrative study on the use of nano foams for vehicular applications is presented by using a vehicle bumper numerical model. The carbon nano foam is installed into the cavity of the bumper model and a full-frontal crash simulation is performed. Overall, this study has shown that the energy absorption capacity of thin-walled structures can be significantly enhanced with the use of carbon nano foams.

2014 ◽  
Vol 599 ◽  
pp. 141-144 ◽  
Author(s):  
M. Afrasiab ◽  
G. Faraji ◽  
V. Tavakkoli ◽  
M.M. Mashhadi ◽  
A.R. Bushroa

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 (19) ◽  
pp. 4304
Author(s):  
Miroslaw Ferdynus ◽  
Patryk Rozylo ◽  
Michal Rogala

The paper presents the results of numerical tests of impact and energy absorption capacity of thin-walled columns, subjected to axial impact loading, made of aluminum alloy, and having a square cross-section and spherical indentations on their lateral surfaces. The numerical models were validated using an experiment that was conducted on the Instron CEAST 9350 High Energy System drop hammer. Material properties of the applied aluminum alloy were determined on the basis of a static tension test. The crushing behavior of the columns and some crashworthiness indicators were investigated. On the basis of the results of the conducted analyses, conclusions were drawn about the most beneficial design/constructional variants in terms of achieved crashworthiness parameters.


Author(s):  
Zhichao Li ◽  
Subhash Rakheja ◽  
Wen-Bin Shangguan

Thin-walled structures are widely used as energy absorbers in automotive vehicles due to their lightweight and high-energy absorption efficiency. In order to improve the energy absorption characteristics of thin-walled structures subjected to different loading angles, different types of novel multi-cell structures are proposed in this paper. The numerical method is used to study the crushing behaviors of the proposed multi-cell structures under different loading angles. It is found that the proposed multi-cell structures have considerably small initial peak force under axial load and avoid the appearance of global buckling deformation mode under oblique loads. Moreover, reasonably distributed wall thickness for each square tube in the thin-walled structure can enhance its energy absorption capacity under different loading angles.


2019 ◽  
Vol 11 (1) ◽  
pp. 41-68 ◽  
Author(s):  
Chukwuemeke William Isaac

The dynamic oblique crushing of circular thin-walled tubes with the presence of non-propagating crack was investigated numerically. The material considered was strain rate sensitive with crack located at the distal end of the tube. Major crashworthiness parameters were obtained and the analysis of the structural response for idealized and finite element crushed thin-walled tubes was also carried out. The study shows that crack initiation on energy absorbing tubes increase their crushing force efficiency under oblique impact, decrease their crushing force efficiency under axial impact and reduce their crashworthiness performance such as the energy absorption capacity and specific energy absorption under axial and oblique impact. Results of the crashworthiness parameters, deformation modes, damage morphology, stress–strain relations, absorption energy characteristics and crushing force-displacement history were obtained. Furthermore, the numerical study reveals both the desirable and undesirable consequence of crack on the overall crashworthiness performance of energy absorbing circular thin-walled tubes.


BioResources ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. 5985-6002
Author(s):  
Peng Cheng ◽  
Qingchun Wang ◽  
Shi Ke

The specific energy absorption of a thin-walled tube can be improved by filler. This study examined the potential use of a cheaper biomass filler, paper scraps, to enhance the energy absorption characteristics of the structure while reducing its cost, compared to that with a traditional filler such as foam material. Quasi-static crushing tests and finite element simulations were performed by using the explicit non-linear finite element software LS-DYNA to determine the improvements to the mean crushing force and specific energy absorption of the steel tube when filled with different densities of paper scraps. The mean crushing force and specific energy absorption of the empty tube, the paper scraps, and thin-walled tube filled with paper scraps were determined, and corresponding numerical simulations were performed. The simulation and test results showed that the impact performance of tube filled with paper scraps was greatly improved when paper scraps density was 0.35 g/cm3. By optimizing paper scraps filling structure, a new structure that could further enhance the specific energy absorption was obtained. The optimal scheme could increase the specific energy absorption of Q345 steel tube by 11.35%.


2018 ◽  
Vol 8 (6) ◽  
pp. 3640-3645
Author(s):  
T. Sunar ◽  
M. Cetin

Light structures and parts are very effective for new engineering applications. Their considerably low densities, high energy absorption capabilities, and desirable mechanical properties make them useful for particularly automotive, defense and aerospace industries. Besides these positive properties, it is known that the production and processing of cellular materials is very tough and worth the effort. Recently, with advances in new technologies like 3D printing or selective laser melting, now different types of cellular materials can be produced. But manufacturing of metallic foams via casting especially replication or infiltration method is fairly an economic method when compared with other methods. In this study, vacuum-gas infiltration set-up was used to produce B4C reinforced aluminum foams. The mentioned method involves the addition of space holder materials and a dissolution technique to remove them after solidification of the metal. As space holder materials NaCl particles were selected and mixed with B4C powders to produce B4C reinforced A360 aluminum foam. By changing the weight ratio of B4C particles, the alteration of properties like porosity, compression strength, and energy absorption capacity was investigated. Additionally, computer tomography views were obtained to see and interpret the microstructures of the foams. Compression tests were carried out to evaluate the mechanical behavior of the foams under static loading. The porosities of samples obtained as between 65-75%. The compressive strength increased with rising relative density.


Author(s):  
Muhammad Ali ◽  
Khairul Alam ◽  
Eboreime Ohioma

Thin walled axial members are typically used in vehicles’ side and front chassis to improve crashworthiness. 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 presence of functionally graded cellular structures in thin walled members. A functionally graded aluminum cellular core in compact form was placed inside a steel square tube. The crushing behavior was modeled using ABAQUS/Explicit module. The variables affecting the energy absorbing characteristics, for example, deformation or collapsing modes, crushing/ reactive force, plateau stress level, and energy curves, were studied. An approximate 35% increase in the energy absorption capacity of steel tube was observed by adding aluminum graded cellular structure to the square tube. The aluminum graded structure crushed systematically in a layered manner and its presence as core supported the steel square tube side walls in transverse direction and postponed the local (tube) wall collapse. This resulted in composite tube undergoing larger localized folds as compared to highly compact localized folds, which appeared in the steel tube without any graded core. The variation in deformation mode resulted in increased stiffness of the composite structure, and therefore, high energy absorption by the structure. Further, a relatively constant crushing force was observed in the composite tube promoting lower impulse. This aspect has a potential to be exploited to improve the crashworthiness of automobile structures.


Author(s):  
Farid Triawan ◽  
Geraldy Cahya Denatra ◽  
Djati Wibowo Djamari

The study of a thin-walled column structure has gained much attention due to its potential in many engineering applications, such as the crash box of a car. A thin-walled square column usually exhibits high initial peak force, which may become very dangerous to the driver or passenger. To address this issue, introducing some shape patterns, e.g., origami folding pattern, to the column may become a solution. The present work investigates the compressive properties and behavior of a square box column structure which adopts the Miura origami folding pattern. Several test pieces of single-cell Miura origami column with varying folding angle and layer height are fabricated by a 3D printer. The filament is made of Polylactic Acid (PLA), which is a brittle material. Then, compression tests are carried out to understand its compressive mechanical properties and behavior. The results show that introducing a Miura origami pattern to form a thin-walled square column can dramatically lower down the initial peak stress by 96.82% and, at the same time, increase its ductility, which eventually improves the energy absorption capacity by 61.68% despite the brittle fracture behavior.


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