Impact Energy Absorption of Continuous Fiber Composite Tubes

1987 ◽  
Vol 109 (1) ◽  
pp. 72-77 ◽  
Author(s):  
D. W. Schmueser ◽  
L. E. Wickliffe

This paper presents the results of an impact testing program that was conducted to characterize the energy absorption and failure characteristics of selected composite material systems and to compare the results with aluminum and steel. Composite tube specimens were constructed using graphite/epoxy (Gr/Ep), Kevlar/epoxy (K/Ep), and glass/epoxy (Gl/Ep) prepreg tape and were autoclave cured. Vertical impact and static compression tests were performed on 56 tubes. Tests results for energy absorption varied significantly as a function of lay-up angle and material type. In general, the Gr/Ep tubes had specific energy absorption values that were greater than those for K/Ep and Gl/Ep tubes having the same ply construction. Angle-ply Gr/Ep and K/Ep tubes had specific energy absorption values that were greater than those for 1024 steel tubes. Gr/Ep and Gl/Ep angle-ply tubes exhibited brittle failure modes consisting of fiber splitting and ply delamination, whereas the K/Ep angle-ply tubes collapsed in an accordian buckling mode similar to that obtained for metal tubes.

Author(s):  
Alireza Ahmadi ◽  
Masoud Asgari

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.


2018 ◽  
Vol 49 (2) ◽  
pp. 162-180 ◽  
Author(s):  
Zhenyu Wu ◽  
Maolin Wang ◽  
Zhiping Ying ◽  
Xiaoying Cheng ◽  
Xudong Hu

This paper reports the mechanical response of semi-hexagonal part with three different multi-layer reinforcements. Unidirectional, plain woven and orthogonal fabric under quasi-static axial compression were considered. Meso-scale finite element numerical models with failure criterion were also established to simulate the onset and development of internal damage during the compression process. There were two different crush-failure modes occurring in the crush tests of the three different composite samples: a splaying mode for samples with unidirectional fabric, a buckling mode for samples with 3D orthogonal woven fabric and a mixture mode of both buckling and splaying for samples with the plain woven fabric. The samples reinforced by unidirectional fiber have the highest specific energy absorption and lowest peak loading, whereas the samples by 3D orthogonal fabric present the lowest specific energy absorption and highest peak loading. It was also demonstrated by a numerical model that the existence of Z-binder suppresses the delamination by restraining the expanding of warp and weft yarns. The comparison of numerical results and experimental data indicates that the structure of reinforcement has a significant role in the mechanical performance of textile composite.


2019 ◽  
Vol 54 (3) ◽  
pp. 176-191 ◽  
Author(s):  
Yanfeng Guo ◽  
Meijuan Ji ◽  
Yungang Fu ◽  
Dan Pan ◽  
Xingning Wang ◽  
...  

The composite layered structures including paper corrugation, paper honeycomb and expandable polyethylene are innovative structures of cushioning energy absorption, and the compression and impact resistances of the expandable polyethylene can be enhanced by laminating the corrugated paperboard or honeycomb paperboard. This article evaluated the compression performance and cushioning energy absorption of the composite layered structures by the static compression and drop impact compression tests. On one hand, the static compression properties showed that the total energy absorption, energy absorption per unit volume and stroke efficiency of the composite layered structures were all higher than those of expandable polyethylene. The specific energy absorption was enhanced with the increase in compression strain but almost not affected by the compression rate. The specific energy absorption of the composite layered structures including the expandable polyethylene and honeycomb paperboard was greater than those of the expandable polyethylene and corrugated paperboard. The energy absorption efficiency of the composite layered structures including the expandable polyethylene and corrugated paperboard was large for the low compression stress level, yet that of the composite layered structures including the expandable polyethylene and honeycomb paperboard was large for the high compression stress level. On the other hand, the dynamic compression characteristics showed that the peak stress, energy absorption per unit area, energy absorption per unit volume and specific energy absorption of the composite layered structures embodying paper sandwich cores and expandable polyethylene had linear increasing trends with the increase of drop shock energy. At the same drop impact condition, the composite layered structures including the honeycomb paperboard and expandable polyethylene had better cushioning energy absorption, the peak stress decreased by 23.6% on average, the energy absorption efficiency raised by 8.85% on average and the specific energy absorption increased by 18.1% on average than those including the corrugated paperboard and expandable polyethylene. Therefore, the corrugated paperboard and honeycomb paperboard can helpfully improve the cushioning energy absorption of the expandable polyethylene, and the composite layered structures embodying the expandable polyethylene, corrugated paperboard and honeycomb paperboard may hold excellent packaging protection.


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%.


2020 ◽  
Vol 54 (27) ◽  
pp. 4253-4268
Author(s):  
Mou Haolei ◽  
Xie Jiang ◽  
Zou Jun ◽  
Feng Zhenyu

To research the failure of carbon fiber-reinforced composite laminated specimens, the tensile tests and compressive tests were conducted for [90]16 and [0]16 specimens, and the shear tests were conducted for [±45]4s specimens, and the microscopic failure mechanisms were observed by scanning electron microscopy. To research the failure and energy absorption of different thin-walled structures with different layups, the quasi-static axial crushing tests were conducted for [±45/0/0/90/0]s and [0/90]3s circular tubes, [0/90]3s and [±45]3s square tubes, [0/90]4s and [±45]4s sinusoidal specimens, and the internal failure were further investigated by 3D X-ray scan. Based on the load-displacement curves, the energy absorptions were evaluated and compared according to specific energy absorption and peak crushing force, and the relationships between failure modes and specific energy absorption, peak crushing force were further researched. The results show that the macroscopic failure modes are the collective results of varieties of microscopic failure mechanisms, such as fiber fracture, matrix deformation and cracking, interlamination and intralamination cracks, cracks propagation, etc. The [±45/0/0/90/0]s circular tube shows the transverse shearing failure mode with high specific energy absorption. The [±45]3s square tube and [±45]3s sinusoidal specimen show the local buckling failure mode with low specific energy absorption. The [0/90]4s sinusoidal specimen, [0/90]3s circular tube, and [0/90]3s square tube show the lamina bending failure mode with medium specific energy absorption. The failure mode of thin-walled structure can be changed by reasonable layups design, and the energy absorption can further be improved.


2021 ◽  
Author(s):  
Zhenyang Gao ◽  
Hua Sun ◽  
Hongze Wang ◽  
Yi Wu ◽  
Tengteng Sun ◽  
...  

Abstract For numerous engineering applications, there is a high demand for protective lightweight structures with outstanding energy absorption performance and the ability to prevent catastrophic structural failures. In nature, most species have evolved with hierarchical biological structures that possess novel mechanical properties, including ultrahigh specific energy absorption, progressive laminated failure modes, and ability for crack arrestment, in order to defend themselves from hostile environments. In this study, a novel protective metamaterial having spherical hollow structures (SHSs) was developed with different hierarchical microstructures. An artificial failure mode engineering strategy was proposed by tailoring the microstructures of SHS unit cells. To demonstrate the effectiveness of the proposed method, a composite hierarchical SHS lattice structure was developed using a biomimetic laminated failure mode and through a hardening mechanism, mimicking crystal grain boundaries. The quasi-static compressive results indicated a significant improvement in the specific energy absorption, an enhanced plateau stress magnitude, and an obvious delay in the densification stage for the composite hierarchical SHS lattice owing to the constraining effect of its mesoscale grain boundaries and an increased number of intensively engineered laminated failure levels. This novel type of metamaterial was shown to be immensely beneficial in designing lightweight protective aerospace components such as turbine blade lattice infills.


Author(s):  
Wensong Yang ◽  
Assimina A. Pelegri

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.


2016 ◽  
Vol 673 ◽  
pp. 141-149 ◽  
Author(s):  
H.H. Ya ◽  
H. El-Sobky

–The behaviour of extruded glass fibre reinforced thermoplastic pipe under axial crushing load was investigated experimentally. It was envisaged that the difference between the axial and hoop moduli and strengths as well as the volume fraction would influence the mode of collapses and energy absorption. The moduli could be varied using a new extrusion technology, which controls the fibre orientation pattern, hence, the mechanical properties. The ability to vary the moduli and the fibre volume fraction provide means of controlling the collapse mode in order to optimise specific energy absorption. Axial compression tests were performed on glass filled Polypropylene and Polyethylene composite pipes. The samples were chosen with a variety of fibre volume fraction, Vf = 5% to 20% and average angle of orientation, θ = 50o to 80o to evaluate the effect of anisotropy and Vf on the energy absorption capacity and collapse modes. The observations indicate that, the samples containing of higher Vf and θ, collapsed in brittle failure mode (fragmentation), while those with less Vf and θ angle collapsed in non-axis-symmetric (diamond) mode with local fracture. The galss fillet with polypropylene-60o (GPP-60) displayed the highest specific energy absorption (Es) compared to the other GPE, MDPE and LDPE pipe samples. However, the glass fillet polyethylene – 75o (GPE-75) displayed the highest Es and the glass fillet polyethylene – 65o (GPE-65) displayed the lowest Es compared with in the GPE pipes. The specific energy absorption of GPP-70 pipe (24 kJ/kg) and GPE-75 pipe (12 kJ/kg) is almost 50 % and 25% of the amount of specific energy absorption of aluminium tubes (60 kJ/kg), respectively. Moreover, it is close to the specific energy absorption of glass-epoxy 15o (GE-15) / which is 30 kJ/kg, and much higher than aramid-epoxy-15o (AE-15)/ which is 9 kJ/kg.


2015 ◽  
Vol 778 ◽  
pp. 18-23
Author(s):  
Jing Hui Zhao ◽  
Jian Feng Wang ◽  
Tao Liu ◽  
Na Yang ◽  
Wen Jie Duan ◽  
...  

Aluminum honeycomb is a lightweight material with high strength and strong capacity of energy absorption. In order to research energy absorption characteristic of aluminum honeycomb material, quasi-static and dynamic out-of-plane compression experiments are carried out on a double-layer aluminum honeycomb impact attenuator of one FSAE racing car. Plateau stress (PS), specific load (SL), mass specific energy absorption (MSEA), volume specific energy absorption (VSEA) and other parameters of the tested aluminum honeycomb under both quasi-static and dynamic impact conditions are analyzed. The results show that the tested aluminum honeycomb impact attenuator has good energy absorption capacity to meet the collision requirements. Furthermore, under the condition of dynamic impact, the energy absorption capacity of this honeycomb improves compared with that under the condition of quasi static compression.


Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 315
Author(s):  
Ivana Bunjan ◽  
Krešimir Grilec ◽  
Danko Ćorić

In this study, aluminum foams reinforced with different steel elements were produced by the AluLight process. The master alloy AlMgSi0.6 was used as the matrix material, titanium hydride (TiH2) powder was used as a foaming agent, and steel wire, cylindrical steel mesh and flat steel mesh were used as reinforcing elements. Reinforcements were placed inside the mold, along with the precursors, and samples were manufactured by gas releasing particles in a semi-solid state. To examine the effect of the reinforcements on specific energy absorption, quasi-static uniaxial compression tests were carried out, with a constant separation rate of 1 mm/s. From the tested results, the energy absorption per unit volume and specific energy absorption efficiency were calculated and then also statistically evaluated. The results showed that examined shapes of reinforcements affect differently specific energy absorption and its efficiency, compared to non-reinforced aluminum foams. The best result obtained was with cylindrically shaped steel mesh.


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