Influence of interphase material and clay particle shape on the effective elastic properties of epoxy/clay nanocomposites (ECNs) containing randomly oriented exfoliated nanoclay particles is investigated by using the Mori-Tanaka method and a hybrid method. The effective particle concept is used to model the clay particle surrounded by the interphase material. Non-uniform distribution of the aspect ratio (AR) of clay particles is modelled by using the Gauss and rectangular distributions. The results indicate that the interphase thickness, interphase stiffness, clay AR distribution and clay particle shape have a significant influence on the Young's modulus of ECNs, but not on the Poisson's ratio. However, Poisson's ratio of the interphase material has a considerable influence on the Poisson's ratio of ECNs. Finally, a comparison of analytical and experimental results is presented. © 2015 Elsevier Ltd.

R. Velmurugan

Department of Aerospace Engineering

Elastic moduli

Nanocomposites

Nanostructures

Poisson distribution

Poisson ratio

Computational modelling

EFFECTIVE ELASTIC PROPERTY

EPOXY/CLAY NANOCOMPOSITES

INTERPHASE MATERIALS

INTERPHASE THICKNESS

MORI TANAKA METHOD

Non-uniform distribution

RECTANGULAR DISTRIBUTIONS

Aspect ratio

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Composites Part B: Engineering

A novel hybrid method is developed to compute the effective properties of composites containing arbitrarily shaped inclusions. In this method, finite element analysis of a single inclusion representative volume element model is used to compute the Eshelby tensor of the inclusion. This tensor is substituted into Mori-Tanaka model to compute the effective properties. Predictions by the hybrid method are compared with the predictions by a pure analytical method as well as a pure numerical method. Results indicate that the composites with triangular, rectangular and irregular section inclusions have significantly better effective properties than the corresponding composites with circular section inclusions. © 2015 Elsevier Ltd All rights reserved.

Computers and Structures

A hybrid method for computing the effective properties of composites containing arbitrarily shaped inclusions

Composite laminates made of glass/epoxy with and without nano fillers were subjected to projectile impact. The laminates of different thicknesses were prepared by hand lay-up and compression molding processes. Laminates were made from glass woven roving mats of 610 gsm, epoxy resin and nano clay of 1-5 wt.% of matrix. A piston type gas gun setup was used to impact a spherical nose projectile of diameter 9.5 mm and mass of 7.6 g, on the nanocomposite laminates at impact velocities in the range of their ballistic limit and above. The energy absorbed during penetration and ballistic limit of the nanocomposite laminates were studied both experimentally and analytically. The analytical model also predicts the energy absorbed in various failure modes due to tensile failure of primary fibers, deformation of secondary fibers, delamination and matrix crack. Mechanical properties like tensile modulus, stress-strain function, shear modulus, and strain energy release rate were used as input to the analytical model. Laminates of three, five and eight layers have been considered for the analysis. The effect of clay dispersion in the matrix for different failure modes is discussed. Ballistic limit obtained from the model is validated with experimental results and good agreement is found. © 2014 Elsevier Ltd. All rights reserved.

International Journal of Impact Engineering

Energy absorption and ballistic limit of nanocomposite laminates subjected to impact loading

The diglycidyl ether of bisphenol A (DGEBA) epoxy resin system filled with organo clay (OC) and unmodified clay (UC) were processed separately by two different curing agents. Triethylene tetramine (TETA) and Diaminodiphenyl methane (DDM) hardeners were used as curing agents. The nanocomposites were processed by shear mixing at different clay concentrations (1, 2, 3,5 and 10 wt%). The OC and UC were characterized by x-ray diffraction (XRD) technique. The morphology of the nanocomposites was obtained by XRD and Transmission Electron Microscopy (TEM). Bending and Impact tests conducted on these materials revealed that the organo clay filled epoxy resin showed good improvement in property over unmodified clay filled epoxy composites. The mass uptake of the nanocomposites was studied in the acid, base and water mediums. It is observed that the mass uptake in the acid medium is higher than in other mediums. The equilibrium mass uptake in all the mediums for nanocomposites was found to be lower compared to neat epoxy polymer system. © 2006 Springer Science + Business Media, Inc.

Journal of Materials Science

Mechanical and barrier properties of epoxy polymer filled with nanolayered silicate clay particles

Diglycidyl ether of bisphenol-A (DGEBA) epoxy resin system filled individually with organoclay (OC) and unmodified clay (UC) were synthesized by mechanical shear mixing with the addition of diamino-diphenylmethane (DDM) hardener. The unmodified clay used was Na+-Montmorillonite (MMT) and the organoclay was alkyl ammonium treated MMT clay. The reinforcement effect of OC and UC in the epoxy polymer on thermal, mechanical and vibration properties were studied. X-ray diffraction (XRD) and Transmission electron microscopy (TEM) were used to study the structure and morphology of nanocomposites. Curing study shows that the addition of OC in epoxy resin aids the polymerization by catalytic effect, and UC addition does not show any effect in the curing behavior of epoxy polymer. Thermogravimetry analysis (TGA) shows enhanced thermal stability for epoxy with OC fillers than that of epoxy with UC fillers. The epoxy with OC fillers shows considerable improvement on tensile and impact properties over pure epoxy polymer and epoxy with UC fillers. The improvement in tensile and impact properties of nanocomposites is supported with the fracture surface studies. Epoxy with OC fillers shows enhanced vibration characteristics than that of the pure epoxy polymer and epoxy with UC fillers.

Thermal, mechanical and vibration characteristics of epoxy-clay nanocomposites

A developed model to assume the interphase properties in a ternary polymer nanocomposite reinforced with two nanofillers

Influence of interphase material and clay particle shape on the effective properties of epoxy-clay nanocomposites

Journal	Data powered by TypesetComposites Part B: Engineering
Publisher	Data powered by TypesetElsevier Ltd
ISSN	13598368
Open Access	No