This paper presents the experimental study of free vibration and damping characteristics of hybrid nanocomposite laminates by reinforcing short fibre chopped strand mat and organically modified montmorillonite clay (0, 1, 3 and 5 wt.%) in the vinyl ester matrix by hand lay-up technique. Theoretical study is also carried out to study the vibration and damping characteristics of hybrid nanocomposites. Dynamic result shows that the second phase nanoscale dispersion in the matrix and E-glass fibre significantly enhances the internal damping of hybrid composites. © 2007 Elsevier B.V. All rights reserved.

R. Velmurugan

Department of Aerospace Engineering

M. Ramesh Kumar

Clay Minerals

Damping

Esters

Glass fiber reinforced plastics

Laminates

Molecular vibrations

Hybrid composites

NANOSCALE DISPERSION

Clay

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

Materials Letters

Composite laminates are made of glass woven roving mats of 610gsm, epoxy resin and nano clay which are subjected to projectile impact. Nano clay dispersion is varied from 1% to 5%. Impact tests are conducted in a gas gun setup with a spherical nose cylindrical projectile of diameter 9.5 mm of mass 7.6 g. The energy absorbed by the laminates when subjected to impact loading is studied, the velocity range is below ballistic limit. The effect of nano clay on energy absorption in vibration, delamination and matrix crack is studied for different weight % of nano clay and for different thickness values of the laminates. The natural frequencies and damping factors are obtained for the laminates during impact and the effect of nano clay is studied. The results show considerable improvement in energy absorption due to the presence of nano clay. © 2015, Brazilian Association of Computational Mechanics. All rights reserved.

Fulltext

Latin American Journal of Solids and Structures

Vibration and energy dissipation of nanocomposite laminates for below ballistic impact loading

The objective of this paper is to study the vibrational damping characteristics during medium velocity impact of nanoclay filled glass fiber reinforced epoxy hybrid laminates. A series of laminates with varying degree of nanoclay concentration (0-5 wt.%) and fiber weight fraction (25-75 wt.%) were prepared by vacuum assisted resin infusion molding (VARIM) method. The laminates were subjected to medium velocity projectile impact using in-house built gas gun set-up and the ballistic limit of laminates series was determined. The result indicated that during impact, the laminate undergoes vibrational damping. This damping property is a function of fiber weight fraction and orientation, nanoclay concentration and nanocomposite structure. A 42% increase of ballistic limit was observed for 5 wt.% nanoclay filled hybrid (50 wt.% fiber) when compared with unfilled composite. Structural and modal analysis of hybrids showed that the increased ballistic limit of nanoclay filled hybrids is due to the nanocomposite structure and improved damping and fracture properties. © 2015 Elsevier Ltd.

Composites Part B: Engineering

Damping characteristics of nanoclay filled hybrid laminates during medium velocity impact

Laminated composites with nano fillers are subjected to medium velocity impact. The laminates are prepared by hand lay-up technique followed by compression moulding, for different thicknesses. Laminates are made of glass woven roving mates of 610 gsm, epoxy resin and nano clay. Clay dispersion is varied from 1% to 5% by weight. A piston type gas gun set up is employed to impact the composite laminates. Spherical nose cylindrical projectile, of diameter 9.5 mm and mass 7.6 g, is used for the study. The impact tests are conducted to predict the ballistic limits of the laminates with and without clay. Quasi-static deflection tests and dynamic tests are carried out to find the energy absorbed by the laminates. Dispersion of clay in polymer matrix shows considerable improvement in energy absorption and ballistic limit of the composite laminates. © 2013 Taylor and Francis Group, LLC.

International Journal of Crashworthiness

Energy absorption characteristics of glass/epoxy nano composite laminates by impact loading

Modal analysis is carried out on pre and post impacted nano composite laminates. The laminates are prepared using 3, 5 and 8 layers of 610gsm glass woven roving mats(WRM) with epoxy resin and montmorillonite(MMT) clay content is varied from 1% to 5%. Impulse hammer technique is used to find natural frequency and damping factor of laminates. Medium velocity impact tests are conducted by using a gas gun. The vibration responses of natural frequency and damping factor are obtained and are studied for laminates with all edges clamped boundary conditions. Results show considerable improvement in natural frequency and damping factor due to nano clay addition. It is also seen that the nano clay controls the delamination due to impact loading.

Modal analysis of pre and post impacted nano composite laminates

Materials & Design

On the tensile and shear strength of nano-reinforced composite interfaces

Composites Science and Technology

Nanoclay reinforcement effects on the cryogenic microcracking of carbon fiber/epoxy composites

Composite Structures

Damping studies in fiber-reinforced composites – a review

Effects of wet ball-milling on particle dispersion and mechanical properties of particulate epoxy composites

Journal of Materials Science

Particulate-fibre-reinforced glass matrix hybrid composites

Effect of nanoclay addition on vibration properties of glass fibre reinforced vinyl ester composites

Journal	Materials Letters
ISSN	0167577X
Open Access	No