scholarly journals Crushing response of circular thin-walled tube with non-propagating crack subjected to dynamic oblique impact loading

2019 ◽  
Vol 11 (1) ◽  
pp. 41-68 ◽  
Author(s):  
Chukwuemeke William Isaac
Keyword(s):  
Energy Absorption ◽  
Numerical Study ◽  
Structural Response ◽  
Oblique Impact ◽  
Absorption Capacity ◽  
Crushing Force ◽  
Propagating Crack ◽  
Thin Walled Tube ◽  
Thin Walled ◽  
Energy Absorbing

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.

Excellent energy absorption capacity of nanostructured Cu–Zn thin-walled tube

2014 ◽  
Vol 599 ◽  
pp. 141-144 ◽  
Author(s):  
M. Afrasiab ◽  
G. Faraji ◽  
V. Tavakkoli ◽  
M.M. Mashhadi ◽  
A.R. Bushroa
Keyword(s):  
Energy Absorption ◽  
Absorption Capacity ◽  
Energy Absorption Capacity ◽  
Thin Walled Tube ◽  
Thin Walled

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.

Energy-Absorbing Characteristics of the Stiffened Thin-Walled Tubes Subjected to Axial Crushing

2013 ◽  
Vol 437 ◽  
pp. 158-163
Author(s):  
Wei Liang Dai ◽  
Xu Guang Li ◽  
Qing Chun Wang
Keyword(s):  
Energy Absorption ◽  
Specific Energy ◽  
Absorption Capacity ◽  
Test Results ◽  
Energy Absorption Capacity ◽  
Specific Energy Absorption ◽  
Axial Crushing ◽  
The Mean ◽  
Thin Walled ◽  
Energy Absorbing

Energy absorbing characteristics of the non-stiffened and stiffened single hat sections subjected to quasi-static axial crushing were experimentally investigated. First non-stiffened hat sections were axially crushed, then structures with different stiffened methods (stiffened in hat and stiffened in the plate) were tested, finally energy absorption capacities of these structures were compared. Test results showed that, for the appropriate designed stiffened tube, the mean crush force and mass specific energy absorption were increased significantly compared to the non-stiffened. Stiffened in hat section showed a little more energy absorption capacity than that stiffened in the plate, but the structure may sustain a global bending.

Energy absorption characteristics of thin-walled steel tube filled with paper scraps

BioResources ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. 5985-6002
Author(s):  
Peng Cheng ◽  
Qingchun Wang ◽  
Shi Ke
Keyword(s):  
Finite Element ◽  
Energy Absorption ◽  
Specific Energy ◽  
Steel Tube ◽  
Specific Energy Absorption ◽  
Crushing Force ◽  
Thin Walled Tube ◽  
The Mean ◽  
Thin Walled ◽  
Absorption Characteristics

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%.

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

2014 ◽  
Author(s):  
D. Tankara ◽  
R. Moradi ◽  
Y. Y. Tay ◽  
H. M. Lankarani
Keyword(s):  
Energy Absorption ◽  
Research Work ◽  
High Energy ◽  
Primary Objective ◽  
Absorption Capacity ◽  
Collapse Mechanism ◽  
Compression Tests ◽  
Thin Walled Tube ◽  
Thin Walled ◽  
Absorption Characteristics

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.

Crushing Analysis of Tapered Ellipse Tubes Under Oblique Impact Loading

2016 ◽  
Author(s):  
Qiang Gao ◽  
Liangmo Wang ◽  
Yuanlong Wang ◽  
Fuxiang Guo ◽  
Zunzhi Zhang
Keyword(s):  
Cross Sections ◽  
Impact Loading ◽  
Oblique Impact ◽  
Nonlinear Finite Element ◽  
Element Analysis ◽  
Specific Energy Absorption ◽  
Crushing Force ◽  
Thin Walled ◽  
Energy Absorbing ◽  
Load Angle

In this paper, a class of axisymmetric thin-walled tubes with two types of geometries (straight and tapered) and four kinds of cross-sections (square, rectangle, circle, ellipse) are considered as energy absorbing components under oblique impact loading. The crash behavior of these tubes are first investigated by nonlinear finite element analysis through LS-DYNA. It is found that the tapered tubes has the better crashworthiness performance than the straight ones under oblique impact regarding both specific energy absorption (SEA) and peak crushing force (PCF). Among the tapered tubes, the tapered ellipse tube (TET) has the best crashworthiness performance. Then by calculating the overall SEA considering load angle uncertainty effect, it is found that the weighting factors for different load angles are critical for evaluating the crashworthiness performance of the tubes.

Effects of Functionally Graded Cellular Core on Energy Absorption Response of Thin Walled Composite Axial Members

2016 ◽  
Author(s):  
Muhammad Ali ◽  
Khairul Alam ◽  
Eboreime Ohioma
Keyword(s):  
Energy Absorption ◽  
Compressive Loading ◽  
Deformation Mode ◽  
High Energy ◽  
Steel Tube ◽  
Absorption Capacity ◽  
Functionally Graded ◽  
Composite Tube ◽  
Thin Walled ◽  
Energy Absorbing

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.

Dynamic crashing behavior of thin-walled conical tubular structures with nonlinearly-graded diameters

2018 ◽  
Vol 233 (7) ◽  
pp. 2456-2466 ◽  
Author(s):  
Fengxiang Xu ◽  
Suo Zhang ◽  
Kunying Wu
Keyword(s):  
Energy Absorption ◽  
Absorption Capacity ◽  
Geometrical Parameters ◽  
Tubular Structures ◽  
Power Law Distribution ◽  
Thin Walled Structures ◽  
Conical Structure ◽  
Thin Walled ◽  
Energy Absorbing ◽  
Effective Design

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.

Energy absorption properties of thin-walled square tube with lateral piecewise variable thickness under axial crashing

2019 ◽  
Vol 36 (8) ◽  
pp. 2588-2611
Author(s):  
Shutian Liu ◽  
Xueshan Ding ◽  
Zeqi Tong
Keyword(s):  
Numerical Calculation ◽  
Energy Absorption ◽  
Variable Thickness ◽  
Absorption Properties ◽  
Content Type ◽  
Explicit Formulation ◽  
Crushing Force ◽  
Thin Walled Tube ◽  
The Mean ◽  
Thin Walled

Purpose This paper aims to study the energy absorption properties of the thin-walled square tube with lateral piecewise variable thickness under axial crashing and the influence of the tube parameters on energy absorption. Design/methodology/approach In this work, the energy absorption properties of the thin-walled square tube were analyzed by theoretical, numerical and experimental approach. The numerical results are obtained based on the finite element method. The explicit formulation for predicting the mean crushing force of the tube with lateral piecewise variable thickness was derived based on Super Folding Element method. The limitation of the prediction formulation was analyzed by numerical calculation. The numerical calculation was also used to compare the energy absorption between the tube with lateral piecewise variable thickness and other tubes, and to carry out the parametric analysis. Findings Results indicate that the thin-walled tube with lateral piecewise variable thickness has higher energy absorption properties than the uniform thickness tubes and the tubes with lateral linear variable thickness. The thickness of the corner is the key factor for the energy absorption of the tubes. The thickness of the non-corner region is the secondary factor. Increasing the corner thickness and decreasing the non-corner thickness can make the energy absorption improved. It is also found that the prediction formulation of the mean crushing force given in this paper can quickly and accurately predict the energy absorption of the square tube. Originality/value The outcome of the present research provides a design idea to improve the energy absorption of thin-walled tube by designing cross-section thickness and gives an explicit formulation for predicting the mean crushing force quickly and accurately.

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