Gradient-degraded material-induced trigger to improve crashworthiness of composite tubes in a controlled manner

2019 ◽  
Vol 39 (1-2) ◽  
pp. 60-77 ◽  
Author(s):  
Hongyong Jiang ◽  
Yiru Ren ◽  
Jianqiang Zheng

A type of gradient-degraded material-induced trigger has a greater potential to induce a progressive crushing mode in a controlled manner to reduce the initial crushing load and increase the specific energy absorption. Thus, different material degradation strategy-based triggers are designed to improve the crashworthiness of composite tubes. To understand the triggering mechanisms, effects of height of trigger and level of degradation are studied using single material degradation strategies. In turn, gradient material degradation strategies are novelly presented to explore different crushing behaviors of tube. Further, an improved gradient material degradation gathering all features of single material degradation and gradient material degradation is proposed. The virtual quasi-static crushing tests are conducted where the model considers intra-ply and inter-ply failure initiation and damage evolution. The crushing behaviors of all triggered tubes are compared. From the predicted results, it is found that both the height of trigger and level of degradation have significant effects on the crushing behavior. The multi-phased or progressive initial crushing process is presented by using gradient material degradation. By comparison, the tube using the improved gradient material degradation presents 8.26% lower peak load, 8.75% higher specific energy absorption, and 25% higher crushing load stability than the original tube.

2019 ◽  
Vol 227 ◽  
pp. 111292 ◽  
Author(s):  
Grażyna Ryzińska ◽  
Matthew David ◽  
Gangadhara Prusty ◽  
Jacek Tarasiuk ◽  
Sebastian Wroński

2019 ◽  
Vol 54 (10) ◽  
pp. 1281-1304 ◽  
Author(s):  
JE Chambe ◽  
C Bouvet ◽  
O Dorival ◽  
JF Ferrero

The purpose of this study is to evaluate and compare the ability of various composite structures to dissipate the energy generated during a crash. To this end, circular composite tubes were tested in compression in order to identify their behavior and determine their absorbing capabilities using the specific energy absorption (energy absorbed per unit weight). Several composite tubular structures with different materials and architectures were tested, including hybrid composition of carbon–aramid and hybrid configuration of 0/90 UD with woven or braided fabric. Several inventive and experimental trigger systems have been tested to try and enhance the absorption capabilities of the tested structures. Specific energy absorption values up to 140 kJ.kg−1 were obtained, achieving better than most instances from the literature, reaching around 80 kJ.kg−1. Specimens with 0°-oriented fibers coincidental with the direction of compression reached the highest specific energy absorption values while those with no fiber oriented in this direction performed poorly. Moreover, it has consequently been established that in quasi-static loading, a unidirectional laminate oriented at 0° and stabilized by woven plies strongly meets the expectations in terms of energy dissipation. Incidentally, an inner constrained containment is more effective in most cases, reducing the initial peak load without drastically reducing the specific energy absorption value.


2014 ◽  
Vol 23 (2) ◽  
pp. 096369351402300
Author(s):  
Ping Zhang ◽  
Liang-Jin Gui ◽  
Zi-Jie Fan ◽  
Jing-Yu Liu

This paper presented an experimental study on the low-velocity impact response of triaxial braided composite circular tubes, which were fabricated with S-glass/epoxy composite. The impact responses were recorded and analyzed in terms of impact load-displacement curves and specific energy absorption. In addition, four basic failure modes called delaminating, splaying, fragmental fracture and progressive folding were founded. The levels of the mean impact load and specific energy absorption (SEA) are determined by the energy absorption mechanisms, which are related to the dominant failure modes of the tubes. In general, delamination which exhibits the poor energy absorbing performance is the dominant failure mode for all the specimens. Impact test results showed that all three types of tubes had almost the same SEA. Compared to the quasi-static test results, the first peak load and the mean load decrease at about 50% and 10% respectively, SEA generally decreases at an average level 10%.


2018 ◽  
Vol 22 (3) ◽  
pp. 572-598 ◽  
Author(s):  
Hossein Taghipoor ◽  
Mohammad Damghani Nouri

The performance of sandwich structure with expanded metal sheets as the core was studied under axial crushing and transverse impact bending. Relationships between the force and displacement at the mid-span of the sandwich beams were obtained from the experiments. Numerical simulations were carried out using ABAQUS/EXPLICIT and the results were thoroughly compared with the experimental results. Then, the influence of the cell orientation and size of the cell were investigated. It was shown that the cell orientation was a critical parameter affecting the failure mode and energy absorption capability, leading to the increase in the peak load and specific energy absorption during the axial crushing tests. Specific energy absorption of the sandwich beams with lattice core under axial crushing ranges from 117 to 2934 J/kg, which is higher than that of beams under transverse bending. The results showed that the increase in cell angle up to ϴ = 90 increased the energy absorption by 624.4%. It was found that effects of the cell size and cell orientation on the energy absorption were dependent on each other governing the low-velocity impact response of the sandwich beams with lattice cores.


2017 ◽  
Vol 21 (8) ◽  
pp. 2801-2815 ◽  
Author(s):  
A Alantali ◽  
RA Alia ◽  
R Umer ◽  
WJ Cantwell

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.


2019 ◽  
Vol 794 ◽  
pp. 202-207
Author(s):  
Rafea Dakhil Hussein ◽  
Dong Ruan ◽  
Guo Xing Lu ◽  
Jeong Whan Yoon ◽  
Zhan Yuan Gao

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.


2021 ◽  
Vol 1165 ◽  
pp. 47-64
Author(s):  
Saurabh S. Kumar ◽  
Rajesh G. Babu ◽  
U. Magarajan

In this paper, the post ballistic impact behaviour of kevlar-glass fibre hybrid composite laminates was investigated against 9×19 mm projectile. Eight different types of composite laminates with different ratios of kevlar woven fibre to glass fibre were fabricated using hand lay-up with epoxy matrix. Ballistic behaviour like ballistic Limit (V50), energy absorption, specific energy absorption and Back Face Signature (BFS) were studied after bullet impact. The results indicated that as the Percentage of glass fibre is increased there was a linear increment in the ballistic behaviour. Addition of 16% kevlar fabric, composite sample meets the performance requirement of NIJ0101.06 Level III-A. Since the maximum specific energy absorption was observed in Pure Kevlar samples and the adding of glass fibre increases the weight and Areal Density of the sample, further investigations need to be carried out to utilize the potential of glass fibre for ballistic applications.


2019 ◽  
Vol 159 ◽  
pp. 424-440 ◽  
Author(s):  
T.J. Reddy ◽  
V. Narayanamurthy ◽  
Y.V.D. Rao

Author(s):  
Sadjad Pirmohammad

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).


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