scholarly journals Experimental and multiscale numerical investigations on low-velocity impact responses of syntactic foam composites reinforced with modified MWCNTs

2021 ◽  
Vol 10 (1) ◽  
pp. 883-903
Author(s):  
Yi Wang ◽  
Jun Wang ◽  
Jie Wang ◽  
David Hui

Abstract This study focused on experimental and numerical investigations into the low-velocity impact behavior of epoxy resin matrix syntactic composites with embedded hollow glass microspheres (HGMs) and multiwalled carbon nanotubes (MWCNTs). The synergistic effects of HGMs and MWCNTs on the mechanical properties of epoxy resin composites were improved by applying amine and acid treatments to HGMs and MWCNTs, respectively. The influence of the MWCNT content and the applied impact energy on the impact responses and compression strength after the impact of these syntactic foam panel samples were discussed. The results indicated that modifying HGMs and MWCNTs contributed to improving the energy absorption and the strength retention factor (SRF) of these panels and the SRF increased with increased MWCNT content. Moreover, multiscale finite-element (FE) models were developed to simulate panel impact behavior, and modeling results were compared with experimental data. Then, the verified FE model was used to analyze the influence of CNT types (helical CNTs vs MWCNTs) and the diameter-to-thickness ratios of HGMs. This study provided a theoretical basis and design reference for a novel lightweight composite material subjected to low-velocity impact, which could be applied as a core material for sandwich structures in aerospace, marine engineering, transportation, and civil infrastructures.

2016 ◽  
Vol 87 (16) ◽  
pp. 1938-1952 ◽  
Author(s):  
Chao Zhi ◽  
Hairu Long ◽  
Fengxin Sun

The aim of this research was to investigate the low-velocity impact properties of syntactic foam reinforced by warp-knitted spacer fabric (SF-WKSF). In order to discuss the effect of warp-knitted spacer fabric (WKSF) and hollow glass microballoon parameters on the impact performance of composites, eight different kinds of SF-WKSF samples were fabricated, including different WKSF surface layer structures, different spacer yarn diameters and inclination-angles, different microballoon types and contents. The low-velocity impact tests were carried out on an INSTRON 9250 HV drop-weight impact tester and the impact resistances of SF-WKSF were analyzed; it is indicated that most SF-WKSF specimens show higher peak impact force and major damage energy compared to neat syntactic foam. The results also demonstrate that the surface layer structure, inclination-angle of the spacer yarn and the volume fraction and type of microballoon have a significant influence on the low-impact performance of SF-WKSF. In addition, a finite element analysis finished with ANSYS/LS-DYNA and LS-PrePost was used to simulate the impact behaviors of SF-WKSF. The results of the finite element analysis are in agreement with the experimental results.


2000 ◽  
Author(s):  
Uday K. Vaidya ◽  
Scott P. Nelson ◽  
Biju Mathew ◽  
Renee M. Rodgers ◽  
Mahesh V. Hosur

Abstract This paper deals with an innovative integrated hollow (space) E-glass/epoxy core sandwich composite construction that possesses several multi-functional benefits in addition to the providing light-weight and bending stiffness advantages. In comparison to traditional foam and honeycomb cores, the integrated space core provides a means to route wires/rods, embed electronic assemblies, and store fuel and fire-retardant foam, among other conceivable benefits. In the current work the low velocity impact (LVI) response of innovative integrated sandwich core composites was investigated. Three thickness of integrated and functionality-embedded E-glass/epoxy sandwich cores were considered in this study — including 6mm, 9mm and 17 mm. The low-velocity impact results indicated that the hollow and functionality embedded integrated core suffered a localized damage state limited to a system of core members in the vicinity of the impact. Stacking of the core was an effective way of improving functionality and limiting the LVI damage in the sandwich plate. The functionality-embedded cores provided enhanced LVI resistance due to energy additional energy absorption mechanisms. The high strain rate (HSR) impact behavior of these sandwich constructions is also studied using a Split Hopkinson Pressure Bar (SHPB) at strain rates ranging from 163 to 653 per second. The damage initiation, progression and failure mechanisms under low velocity and high strain rate impact are investigated through optical and scanning electron microscopy.


2014 ◽  
Vol 564 ◽  
pp. 406-411
Author(s):  
Parnia Zakikhani ◽  
R. Zahari ◽  
Mohamed Thariq Hameed Sultan

Impact simulation with finite element analysis is an appropriate manner to reduce the cost and time taken to carry out an experimental testing on a component. In this study, the impact behavior of the composite hemispherical shell induced by low velocity impact is simulated in ABAQUS software with finite element method. To predict the responses of Kevlar fabric/polyester, glass fabric/polyester and carbon fabric/polyester in the form of a hemisphere, once as one layer and then as a three-layered composite under applied force by an anvil. The sequences of layers are changed, to investigate and compare the occurred alternations in the amount of energy absorption, impact force and specific energy absorption (SEA). The comparison of results showed that the highest and the lowest quantity of energy absorption and SEA belong to Carbon/Glass/Kevlar (CGK) and Kevlar/Carbon/Glass (KCG) respectively.


2018 ◽  
Vol 49 (4) ◽  
pp. 465-483 ◽  
Author(s):  
Hadi Dabiryan ◽  
Fatemeh Hasanalizade ◽  
Mojtaba Sadighi

Structural parameters of fabrics influence the mechanical behaviour of fabric-reinforced composites. Weft-knitted spacer fabrics have high energy absorption capacity. In this paper, low-velocity impact behavior of composites reinforced with weft-knitted spacer fabrics has been studied using energy-balance method. The effect of fabric geometry on the impact behavior of composites was investigated. A theoretical model was generated to predict the energy dissipated through the impact, considering the structural parameters of fabrics as reinforcement of composites. For this purpose, dissipated energies due to contact, membrane and bending deformation of fabrics, and buckling deformation of spacer yarns were considered. In order to evaluate the proposed model, weft-knitted spacer fabrics with two types of spacer yarn's orientation were used as reinforcement of composites. Low-velocity impact examinations were performed using the drop hammer testing machine. The results showed that the model has about 12 and 13% error in prediction of dissipated energies of different samples. Comparison between theoretical and experimental results confirms that the proposed model is capable to predict the impact behavior of weft-knitted spacer fabric-reinforced composites.


2008 ◽  
Vol 22 (09n11) ◽  
pp. 1355-1360
Author(s):  
SUJIN PARK ◽  
MOONSAENG KIM ◽  
WOOK DOKKO

Steel plates subjected to low velocity impact were numerically analyzed, and physically tested. The impactor has hemispheric tip nose, and the square plate has four fixed edges. Mindlin plate theory and Hertz contact law were used for the formulation of the impact problem, and some numerical treatments for the reduced integration, Newmark time integration scheme, associative flow rule, and plastic hardening were appropriately applied. A simple and efficient analysis program for plate impact was generated, and the results were compared with those of physical impact experiments. A drop test system was installed, and the impact behavior was measured with sensors. The comparison showed reasonable results, and the main parameters of plate impact were also analyzed.


2018 ◽  
Vol 917 ◽  
pp. 218-222 ◽  
Author(s):  
Sonika Sahu ◽  
Mohd Zahid Ansari ◽  
Chong Du Cho

Numerical simulation is performed to study the deformation and failure modes of Al 1100 plate of 2.4 mm thickness, subjected to low-velocity impact. Blunt and hemispherical nose shaped impactors are used in this study. The quasi-static tensile test is performed at a strain rate of 0.01/s to obtain the Johnson-Cook material parameters which are used in numerical simulation software, ABAQUS/CAE to perform impact analysis. Mesh convergence study is carried out to decide the appropriate number of elements for numerical analysis. The impact behavior of Al 1100 plate for each impactor shapes are studied at 22 J impact energy. Result indicate that increased in the nose radius of impactor will increase the amount of deformation energy for aluminium plate.


2008 ◽  
Vol 47-50 ◽  
pp. 1205-1208 ◽  
Author(s):  
Iqbal Kosar ◽  
Khan Shafi Ullah ◽  
Jang Kyo Kim ◽  
Arshad Munir

The influence of nanoclay on the impact damage resistance of carbon fiber-epoxy (CFRP) composites has been investigated using the low-velocity impact and compression after impact tests. The load-energy vs time relations were analyzed to gain insight into the damage behaviors of the materials. Compression-after-impact (CAI) test was performed to measure the residual compressive strength. The CFRPs containing organoclay brought about a significant improvement in impact damage resistance and damage tolerance. The composites containing organoclay exhibited an enhanced energy absorption capability with less damage areas and higher CAI strengths compared to those made from neat epoxy. A 3wt% phr was shown to be an optimal content with the highest damage resistance.


2020 ◽  
pp. 002199832096155
Author(s):  
Mustafa Taşyürek ◽  
Memduh Kara

The aim of this study is to investigate the low velocity impact behavior of pre-stressed glass fiber/epoxy (GRP) nanocomposite tubes. During the production of filament wound tubes with a winding angle of ±55°, carbon nanotubes (CNT) were introduced to the epoxy resin at 0.5%wt and 1.0%wt by ultrasonic method. The nanocomposite tubes were pre-stressed to 32 bars internal pressure, one of the specified operating pressures according to ANSI/AWWA C950 standards. Low velocity impact tests were performed on the pure and CNT added pre-stressed GRP tubes at 5, 10 and 15 Joule energy levels. As a result of the experiments, the contact force-time, force-displacement graphs and absorbed energy values by the samples were obtained. In addition, the damage zones on the specimens were investigated. The effects of CNT reinforcements on the impact response and damage mechanisms of the specimens were evaluated. By adding CNT, it was observed that the damage areas of the samples decreased and was found to affect the impact response of nanocomposite tubes.


2020 ◽  
pp. 152808372098046
Author(s):  
Lekhani Tripathi ◽  
Soumya Chowdhury ◽  
BK Behera

This study was carried out to understand and evaluate the response of 3 D woven fabrics upon the simulated ballistic forces. Under the low-velocity impact, analytical and numerical models were developed for determining the impact energy, which was used to evaluate the ballistic impact of projectile onto multiple-layered woven fabric panels based on the ballistic impact of single textile yarns. The behavior of primary and secondary yarns in a fabric under the ballistic impact was analyzed by both the models. The mechanisms of failure and energy dissipation of Kevlar fabric subjected to low-velocity impact were numerically investigated by using the ABAQUS platform as a tool of finite element method (FEM). The results obtained from numerical and analytical approaches were validated against experimental value which showed a good agreement.


Sign in / Sign up

Export Citation Format

Share Document