Crashworthiness performance of concentric structures with different cross-sectional shapes under multiple loading conditions

Multiple Loading ◽

This paper evaluates the crashworthiness performance of concentric structures with different numbers of tubes (i.e. one to five) and cross-sectional shapes (i.e. hexagon, octagon, decagon and circle) under the multiple loadings of θ = 0, 10, 20 and 30°. An experimentally validated finite element model generated in LS-DYNA is employed to calculate the crashworthiness parameters including the specific energy absorption, maximum crush force and crush force efficiency. A total of 20 concentric structures are analyzed to explore the effects of number of tubes and cross-sectional shapes on the crushing performance. A multi-criteria decision-making method known as TOPSIS is also used to compare and rank the concentric structures in terms of crushing performance. Based on the results, the hexagonal structure including two tubes and octagonal, decagonal and circular structures including three tubes demonstrate the best results among their corresponding cross-sectional shapes. These structures show 9, 39, 38 and 39% higher specific energy absorption compared to their corresponding single tubal cases, respectively. However, in comparison to single tubal cases, they generate 4, 57, 57 and 58% higher maximum crush force, respectively. As such, the values for the improvement of the crush force efficiency are 3, 26, 25 and 21%, respectively. Furthermore, the decagonal structure including three tubes provides the highest energy absorbing characteristics as compared with all the other structures studied in this research. Meanwhile, taking into account all the multiple loading conditions, this structure shows 50% higher specific energy absorption than the hexagonal structure including single tube (as the weakest structure).

Proceedings of the Institution of Mechanical Engineers Part L Journal of Materials Design and Applications ◽

Experimental analysis on the axial crushing and energy absorption characteristics of novel hybrid aluminium/composite-capped cylindrical tubular structures

10.1177/1464420719843157 ◽

2019 ◽

Vol 233 (11) ◽

pp. 2234-2252 ◽

Cited By ~ 9

Author(s):

A Praveen Kumar

Keyword(s):

Energy Absorption ◽

Specific Energy ◽

Cylindrical Tube ◽

Tubular Structures ◽

Aluminium Composite ◽

Cylindrical Tubes ◽

Impact Crushing ◽

Energy Absorbing ◽

The Impact

In recent years, aluminium-composite hybrid tubular structures, which combine the stable and progressive plastic deformation of the aluminium metal with light-weight composite materials, are obtaining increased consideration for meeting the advanced needs of crashworthiness characteristics. This research article presents the experimental outcomes of novel aluminium/composite-capped cylindrical tubes subjected to quasi-static and impact axial loads. The influence of various capped geometries in the aluminium segment and three different fabrics of the composite segment in the cylindrical tube are investigated experimentally. The outcomes of the impact crushing test are also correlated with the quasi-static results of the proposed aluminium/composite-capped cylindrical tubes. The overall outcomes revealed that the crashworthiness characteristics of crushing force consistency and specific energy absorption of the aluminium-composite hybrid tubes are superior to those of the bare aluminium tubes. When the glass fabric/epoxy composite is wrapped to aluminium cylindrical tubes, the specific energy absorption increases about 23–30%, and the wrapping of hybrid glass/kenaf fabrics increases the specific energy absorption of almost 40–52%. Such a hybrid tubular structures would be of huge prospective to be used as effective energy-absorbing devices in aerospace and automotive applications. A further benefit of the composite-wrapping approach is that the composite might be retro-fitted to aluminium tubes, and the energy absorption capability is shown to be significantly enhanced by such utilization.

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

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.437.158 ◽

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 ◽

Axial Crushing ◽

The Mean ◽

Thin Walled ◽

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.

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

Efficient crushable corrugated conical tubes for energy absorption considering axial and oblique loading

10.1177/0954406218806006 ◽

2018 ◽

Vol 233 (11) ◽

pp. 3917-3935 ◽

Cited By ~ 6

Author(s):

Alireza Ahmadi ◽

Masoud Asgari

Keyword(s):

Finite Element ◽

Energy Absorption ◽

Specific Energy ◽

Axial Loading ◽

Element Model ◽

Compression Tests ◽

Static Compression ◽

Thin Walled Structures ◽

Absorption Characteristics

Thin-walled structures are of much interest as energy absorption devices for their great crashworthiness and also low weight. Conical tubes are favorable structures because unlike most other geometries, they are also useful in oblique impacts. This paper investigated the effect of corrugations on energy absorption characteristics of conical tubes under quasi-static axial and oblique loadings. To do so, conical tubes with different corrugation geometries were analyzed using the finite element explicit code and the effects of corrugations on initial peak crushing force and specific energy absorption were studied. The finite element model was validated by experimental quasi-static compression tests on simple and corrugated aluminum cylinders. An efficient analytical solution for EA during axial loading was also derived and compared with the FEM solution. The crushing stableness was analyzed using the undulation of the load-carrying capacity parameter and it was shown that corrugations made collapsing mode, more predictable and controllable. The findings have shown that corrugated conical tubes have much better energy absorption characteristics compared with their non-corrugated counterparts. It was also discovered that during oblique loadings, introducing corrugations can significantly increase the specific energy absorption compared with simple cones.

Energy absorption in aluminium honeycomb cores reinforced with carbon fibre reinforced plastic tubes

Journal of Sandwich Structures & Materials ◽

10.1177/1099636217727145 ◽

2017 ◽

Vol 21 (8) ◽

pp. 2801-2815 ◽

Cited By ~ 3

Author(s):

A Alantali ◽

RA Alia ◽

R Umer ◽

WJ Cantwell

Keyword(s):

Carbon Fibre ◽

Energy Absorption ◽

Specific Energy ◽

Small Diameter ◽

Honeycomb Core ◽

Composite Tubes ◽

Reinforced Plastic ◽

Carbon Fibre Reinforced Plastic ◽

The energy-absorbing behaviour of an aluminium honeycomb core reinforced with unidirectional and woven carbon fibre reinforced plastic composite tubes has been investigated experimentally at quasi-static rates of strain. Small diameter carbon fibre reinforced plastic tubes, with chamfered ends, were inserted into the cells of an aluminium honeycomb in order to yield a lightweight energy-absorbing material. The resulting data are compared with crushing tests on arrays of free-standing composite tubes, supported on a specially designed compression test fixture. The study continues with an investigation into size effects in the energy-absorbing response of these cellular materials, where compression tests are undertaken on four scaled sizes of reinforced honeycomb core. Crushing tests on the multi-tube arrays have shown that woven carbon fibre reinforced plastic tubes absorb significantly greater levels of energy than their unidirectional counterparts. Here, the specific energy absorption did not vary with the number of tubes in the array, with values for the woven tubes averaging 110 kJ/kg and those for the unidirectional tubes averaging 75 kJ/kg. Inserting composite tubes into aluminium honeycomb served to increase the measured specific energy absorption of the core, resulting in values of specific energy absorption of up to 100 kJ/kg being recorded in the woven-based system. Tests on four scaled sizes of core have shown that the measured SEA does not vary with specimen size, indicating that data generated on small samples can be used to represent the energy-absorbing response of larger, more representative components.

Static and Dynamic Crush Behavior of Circular Aluminum Extrusions With Rigid PU Foam Filler

Transportation: Making Tracks for Tomorrow’s Transportation ◽

10.1115/imece2002-32925 ◽

2002 ◽

Author(s):

Salamah Y. Maaita ◽

Golam M. Newaz

Keyword(s):

Energy Absorption ◽

Axial Compression ◽

Specific Energy ◽

Pure Aluminum ◽

Loading Conditions ◽

Aluminum Tube ◽

Compression Loading ◽

Foam Filled ◽

A New Technique

This paper introduces a new technique to increase the specific energy absorption (SEA) for foam-filled circular aluminum tube significantly. The idea is to first utilize initiators to deform the foam inside an aluminum tube under the effects of constraints of the tube wall. Then the aluminum tube and foam are crushed together. In this study, the foam with 190mm length has been filled inside a 200mm aluminum tube and attached to two 50 mm length initiators (one initiator in each side of the tube). Initially, the foam-filled tube has been compressed a total of 90mm by entering and sliding the two initiators inside the aluminum tube. Then the foam, two initiators and the aluminum tube have been compressed together for another 30 mm (The total crushing distance is 120mm). The technique was utilized under quasi-static and dynamic axial compression loading conditions and is found to increase the specific energy absorption (SEA) for the foam-filled circular aluminum tube up to 30% more compared to pure aluminum tubes for quasi-static and dynamic axial compression loading conditions. Both experimental and analytical/computational results are presented.

The effect of loading rate on the compression properties of carbon fibre-reinforced epoxy honeycomb structures

Journal of Composite Materials ◽

10.1177/0021998319900364 ◽

2020 ◽

Vol 54 (19) ◽

pp. 2565-2576 ◽

Cited By ~ 1

Author(s):

RA Alia ◽

J Zhou ◽

ZW Guan ◽

Q Qin ◽

Y Duan ◽

...

Keyword(s):

Carbon Fibre ◽

Strain Rate ◽

Energy Absorption ◽

Specific Energy ◽

Compression Strength ◽

Loading Rate ◽

Honeycomb Cores ◽

Energy Absorbing ◽

Absorption Characteristics

The effect of varying strain rate on the compression strength and energy absorption characteristics of a carbon fibre-reinforced plastic honeycomb core has been investigated over a wide range of loading rates. The honeycombs were manufactured by infusing an epoxy resin through a carbon fibre fabric positioned in a dismountable honeycomb mould. The vacuum-assisted resin transfer moulding technique yielded honeycomb cores of a high quality with few defects. Compression tests were undertaken on single and multiple cells and representative volumes removed from the cores in order to assess how the compression strength and specific energy absorption vary with test rate. Crushing tests over the range of strain rates considered highlighted the impressive strength and energy-absorbing response of the honeycomb cores. At quasi-static rates of loading, the compression strength and specific energy absorption characteristics of the unidirectional samples exceeded those of the multidirectional cores. Here, extensive longitudinal splitting and fibre fracture were the predominant failure mechanisms in the cores. For all three stacking sequences, the single-cell samples offer higher compression strength than their five-cell counterparts. In contrast, the specific energy absorption values were found to be slightly higher in the five-cell cores. The experiments highlighted a trend of increased compression strength with loading rate in the multidirectional samples, whereas the strength of the [0°]4 samples was relatively insensitive to strain rate. Finally, the energy absorbing capacity of all structures studied was found to be reasonably constant at increasing rates of strain.

Investigation of the Specific Energy Absorption of Triply Periodic Minimal Surfaces Subjected to Impact Loading

EPJ Web of Conferences ◽

10.1051/epjconf/202125001022 ◽

2021 ◽

Vol 250 ◽

pp. 01022

Author(s):

Sara AlMahri ◽

Rafael Santiago ◽

Dong-wook Lee ◽

Henrique Ramos ◽

Haleimah Alabdouli ◽

...

Keyword(s):

Strain Rate ◽

Energy Absorption ◽

Specific Energy ◽

Minimal Surfaces ◽

Direct Impact ◽

Loading Conditions ◽

Impact Compression ◽

Triply Periodic Minimal Surfaces ◽

Triply Periodic

Triply periodic minimal surfaces (TPMS) have attracted tremendous research interest due to their lightweight and superior mechanical properties. In this study, two TPMS sheet-based structures (FRD and Neovius) are designed, fabricated, and tested under dynamic and quasistatic loading conditions. Selective laser melting (SLM) is employed to facilitate the fabrication of such complex structures out of stainless steel (SS316L). Scanning electron microscopy (SEM) is utilized to assess the quality of the printed structures. The dynamic compressive behaviour is investigated through performing a direct impact compression test via a Direct Impact Hopkinson Bar (DIHB) at a strain rate of 2000 s-1. Quasi-static tests are also performed at a strain rate of 0.005 s-1. The specific energy absorption (SEA) is compared under both loading conditions to investigate the performance of such structures under dynamic loading. Results show that both structures exhibit higher SEA values under high deformation rates. In fact, Neovius structures outperform FRD structures in terms of specific energy absorption as it exhibits a SEA value of 22.11 J/g and 24.8 J/g SEA in quasi-static and dynamic conditions, respectively.

Numerical Evaluation of Stiffness and Energy Absorption of a Hybrid Unidirectional/Random Glass Fiber Composite

Journal of Engineering Materials and Technology ◽

10.1115/1.4005253 ◽

2011 ◽

Vol 133 (4) ◽

Cited By ~ 2

Author(s):

Wensong Yang ◽

Assimina A. Pelegri

Keyword(s):

Finite Element ◽

Glass Fiber ◽

Energy Absorption ◽

Specific Energy ◽

Hybrid Composite ◽

Fiber Composite ◽

Element Model ◽

Cross Section Area ◽

Glass Fiber Composite

A finite element method is employed to numerically evaluate the stiffness and energy absorption properties of an architecturally hybrid composite material consisting of unidirectional and random glass fiber layers. An ls-dyna finite element model of a composite hollow square tube is developed in which the position of the random fiber layers varies through the thickness. The assessment of the stiffness and energy absorption is performed via three-point impact and longitudinal crash tests at two speeds, 15.6 m/s (35 mph) and 29.0 m/s (65 mph), and five strain rates, ɛ· = 0.1 s−1, 1 s−1, 10 s−1, 20 s−1, and 40 s−1. It is suggested that strategic positioning of the random fiber microstructural architecture into the hybrid composite increases its specific absorption energy and, therefore, enhances its crashworthiness. The simulation data indicate that the composite structure with outer layers of unidirectional lamina followed by random fiber layers is the stiffest due to the considerable superior specific energy absorption of the random fiber micro-architecture. Moreover, it is illustrated that the specific energy absorption increases with the increased ratio of impact contact area over cross-section area. Of all the parameters tested the thickness of the unidirectional laminate on the specific energy absorption does not appear to have a significant effect at the studied thickness ratios.

The crushing characteristics of reinforced Nomex honeycomb

Journal of Reinforced Plastics and Composites ◽

10.1177/0731684418793211 ◽

2018 ◽

Vol 37 (20) ◽

pp. 1267-1276 ◽

Cited By ~ 4

Author(s):

RA Alia ◽

S Rao ◽

R Umer ◽

J Zhou ◽

C Zheng ◽

...

Keyword(s):

Energy Absorption ◽

Specific Energy ◽

Compression Strength ◽

Small Diameter ◽

Areal Density ◽

Mechanical Tests ◽

Stable Model ◽

Nomex Honeycomb ◽

A Nomex honeycomb core has been reinforced with small diameter composite rods and tubes in order to enhance its compression properties and energy-absorbing characteristics. The influence of the areal density of the rods and tubes on the strength and energy-absorbing properties of the reinforced honeycomb was investigated by introducing increasing numbers of rods/tubes in square samples with bonded composite skins. An initial series of crushing tests on arrangements of small tubes and rods resulted in a stable model of failure yielding specific energy absorption values of approximately 45 kJ/kg for the tube and rod-based structures. A subsequent observation of the failed tubes highlighted the similar failure processes to those observed previously following the tests on much larger composite cylinders. Mechanical tests on the Nomex cores have shown that the compression strength and energy-absorbing characteristics of the reinforced honeycombs increase rapidly with increasing composite reinforcement. At low and intermediate values of core density, the rod and tube-reinforced cores exhibited similar properties, in terms of their compression strengths and specific energy absorption, an effect that is likely to be due to the dominance of the heavier Nomex core in these samples. At higher densities, the rod-reinforced systems tended to out-perform their tube-reinforced counterparts. Tests at impact rates of strain have shown that the compression strength and energy-absorbing capabilities of the reinforced cores are higher under the dynamic conditions, with the rod-reinforced cores offering values of specific energy absorption as high as 78 kJ/kg.

Dynamic Axial Compression of Square CFRP/Aluminium Tubes

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.794.202 ◽

2019 ◽

Vol 794 ◽

pp. 202-207

Author(s):

Rafea Dakhil Hussein ◽

Dong Ruan ◽

Guo Xing Lu ◽

Jeong Whan Yoon ◽

Zhan Yuan Gao

Keyword(s):

Energy Absorption ◽

Specific Energy ◽

Fibre Composite ◽

Dynamic Tests ◽

Carbon Fibre Composite ◽

Static Tests ◽

Crushing Force ◽

Cfrp Tubes ◽

The Impact

Carbon fibre composite tubes have high strength to weight ratios and outstanding performance under axial crushing. In this paper, square CFRP tubes and aluminium sheet-wrapped CFRP tubes were impacted by a drop mass to investigate the effect of loading velocity on the energy absorption of CFRP/aluminium tubes. A comparison of the quasi-static and dynamic crushing behaviours of tubes was made in terms of deformation mode, peak crushing force, mean crushing force, energy absorption and specific energy absorption. The influence of the number of aluminium layers that wrapped square CFRP tubes on the crushing performance of tubes under axial impact was also examined. Experimental results manifested similar deformation modes of tubes in both quasi-static and dynamic tests. The dynamic peak crushing force was higher than the quasi-static counterpart, while mean crushing force, energy absorption and specific energy absorption were lower in dynamic tests than those in quasi-static tests. The mean crushing force and energy absorption decreased with the crushing velocity and increased with the number of aluminium layers. The impact stroke (when the force starts to drop) decreased with the number of aluminium layers.