Nanofiber Influence on Low Velocity Impact and on Vibrational Behaviors of Composite Laminate Plates (original) (raw)
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Impact Damage Resistance and Tolerance of Polymer Nanofiber Interleaved Composite Laminates
53rd AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference<BR>20th AIAA/ASME/AHS Adaptive Structures Conference<BR>14th AIAA, 2012
The primary limitation of fiber reinforced composite laminates is their poor interlaminar strength and fracture toughness that result in poor impact damage resistance and tolerance. A number of methods have been tried to address this limitation. These methods are limited by factors such as increase in cost, weight, or loss of in-plane properties. A promising approach which does not degrade the in-plane properties is interleaving. Thermoplastic particle interleaving has been applied to reinforce laminates but the primary concern of in-plane properties degradation has not been addressed. Polymer nano-fiber interleaving was investigated in this dissertation as an alternative approach to particle interleaving. The concept showed promise because of the very high surface area to volume ratio and high strain to fracture of the interleaving Nylon-66 nanofibers. The objectives of the work were to determine the relationship between the electric field and the polymer flow-rate, to improve the electrospinning process, to assess lowvelocity impact damage resistance and tolerance, and to compare the performance of the base laminate to the interleaved laminate. An electrospinning setup with a collector current management technique was developed to match the electric field to the flow-rate. Twenty-four ply quasi-isotropic base and interleaved AS4/3501-6 composite laminates were produced. Interleaving was achieved with 0.7 g/m 2 nano-fabric. The impacted
Impact response of glass/epoxy laminate interleaved with nanofibrous mats
Engineering Solid Mechanics, 2013
Plain and nanofiber-interleaved glass/epoxy laminates clamped according to ASTM D7136 tested under impact loading to assess the improvement in impact resistance of composite laminates that have been interleaved by electrospun polyvinylidene fluoride (PVDF) nanofibers with two different thicknesses. Composite specimens with stacking sequence [0/90/0/90]S were impacted at impact energy of 5J. Variation of the impact characteristics such as maximum contact load, maximum deflection, maximum contact time, absorbed energy are depicted in the figures. The results showed that PVDF nanofibers are not a good choice for toughening epoxy and improving impact damage resistance of GFRP.
Composite Structures, 2014
The necessity to produce modern composites with an acceptable impact resistance is an essential task in automobile and aerospace industry that needs to be satisfied. This capability is addressed by noteworthy energy absorption augmentation which is the most vital characteristic of such composite materials. In this paper, nanofibers are applied as interleaves to modify the delamination strength with a minimum rise in weight and thickness of the high-modulus polypropylene/epoxy composites. Nylon 6,6 nanofibers are produced by the electrospinning method. The distribution of nanofibers across the mats is examined by SEM. Innegra fabrics have been applied in composite layers production. The proper hand lay-up manufacturing of the laminates has been assured by the assistance of a hydraulic press. The energy absorption capacity at the onset of breakdown and impact resistance of the nanomodified and non-modified laminates were determined by quasistatic three-point flexural for the former and low-velocity impact tests for the latter. The obtained results were compared. The results showed a 6.2 and 16.9% increase in the energy absorption capacity of nanomodified laminates in quasi-static three-point flexural test and low-velocity impact tests, respectively. In addition, low-velocity impact tests revealed 16 and 26% improvement in maximum load capacity.
Low-velocity impact performance of nanofiber-interlayered aramid/epoxy nanocomposites
Composites Part B-engineering, 2019
Low-velocity impact response of aramid/epoxy laminates containing nanointerlayers with different amounts of the thickness (17.5, 35, and 70 µm) and various stacking configuration (back-side, central, and two-sides interleaving) has been studied. A hand lay-up method was used for making composites. Instrumented impact tests were compared with quasi-static indentation tests by using the same specimen and test configurations. The results show that generally, quasi-static indentation analysis is sufficient to assess the impact response of interleaved composite only until a certain impact energy level. However, the optimum thickness of interleaves for obtaining the highest value of toughness for interleaved composites is 35 µm. Moreover, the behavior of backside configuration was similar to static tests in impact tests, but other configurations almost did not follow this trend.
Applied Sciences
This paper reviews recent works on the application of nanofibers and nanoparticle reinforcements to enhance the interlaminar fracture toughness, to reduce the impact induced damage and to improve the compression after impact performance of fiber reinforced composites with brittle thermosetting resins. The nanofibers have been mainly used as mats embedded between plies of laminated composites, whereas the nanoparticles have been used in 0D, 1D, 2D, and 3D dimensional patterns to reinforce the matrix and consequently the composite. The reinforcement mechanisms are presented, and a comparison is done between the different papers in the literature. This review shows that in order to have an efficient reinforcement effect, careful consideration is required in the manufacturing, materials selection and reinforcement content and percentage. The selection of the right parameters can provide a tough and impact resistant composite with cost effective reinforcements.
EFFECT OF PAN NANOfiBER INTERLEAVING ON IMPACT DAMAGE RESISTANCE OF GFRP LAMINATES
Abstract: Eight-ply composite laminates of plain and interleaved Glass/Epoxy laminates clamped according to ASTM D7136 were impact tested to assess the improvement in impact resistance of composite laminates that have been interleaved by electrospun PAN nanofiber. Composite specimens with stacking sequence [0/90/0/0] S were impacted at two different impact energies: 3 J and 5J.
In this study, the impact response of glass/epoxy laminates interleaved by Polycaprolactone (PCL) nanofibers is considered. PCL is a thermoplastic polymer, which is a good choice for toughening epoxy-based composite. The impact tests were conducted on curved laminates and under 24 and 36J. The results showed that the effect of interleaving on impact parameters such as maximum load is negligible, but on the other hand could decrease damaged area significantly. By inserting 30m of PCL nanofibers between each layer of laminate the damaged area decreased about 27%.
In this study, the impact response of glass/epoxy laminates interleaved by Polycaprolactone (PCL) nanofibers is considered. PCL is a thermoplastic polymer, which is a good choice for toughening epoxy-based composite. The impact tests were conducted on curved laminates and under 24 and 36J. The results showed that the effect of interleaving on impact parameters such as maximum load is negligible, but on the other hand could decrease damaged area significantly. By inserting 30m of PCL nanofibers between each layer of laminate the damaged area decreased about 27%.
Experimental investigation of the low speed impact characteristics of nanocomposites
Materials & Design, 2013
Nanocomposites have attracted the attention of scientists during the past few decades due to their superior mechanical, thermal, chemical and electrical characteristics. This paper presents the potential of using nanoclay woven Kevlar laminated composites to enhance the impact energy resistance and mechanical performance. The variation of nanoclay percentage usually leads to different characteristics of the resulting composite, and an increase in energy absorption by high percentage of fillers may accompany tendency to delamination. The effect of different percentages of nanoclays on composite properties are investigated in this paper. The results revealed enhancement in delamination resistance at low percentages of nanoclay additives, while the high percentage of nanoclay aggravated the composite delamination. The nanoclay with low percentage (4.3 wt.%) had shown the best results in delamination resistance.
Compression After Impact Behavior of Electrospun Nanofiber Embedded Fiber Glass Composite Laminates
2012
This paper investigates the reduction in compressive residual strength of electrospun nanofiber embedded fiberglass reinforced composite laminates subjected to low velocity impact loading. The fiberglass laminates were fabricated using Tetra Ethyl Orthosilicate (TEOS) chemically engineered glass nanofibers. Impacted specimens were examined using C-scan analysis to estimate impact damage area. Compression-After-Impact (CAI) coupons were obtained from impact tested specimen. Specimens were tested to determine the compressive residual strength. The test data from residual compression strength were compared for the impacted laminates with and without electrospun nanofibers added to lamina interfaces.