This study investigates energy absorption of thermally loaded composites and nanocomposites laminates during impact loading. The laminates are prepared by glass fiber/epoxy with and without nano particles in the matrix system. Nano clay and carbon nano tube are used as filliers in the epoxy matrix. The composites specimens are subjected to impact loading at 0° C, 30° C and 60° C temperature environments. A gas gun impact testing facility is used for propelling the projectile of mass 7.6 g and diameter 9.5 mm with hemi spherical nose. The initial and residual velocities of projectile are predicted to find the energy absorbing capacity of laminates. The energy absorption and delamination area of the specimens are analyzed and discussed for the laminates with and without clay. Also, the ballistic limit is predicted for the specimens of nanocomposites made with glass fibers and epoxy matrix, and the effect of temperature on impact resistance is discussed. Analytical model is developed and the energy absorption characteristics are also studied. © 2017 The Authors.

R. Velmurugan

Department of Aerospace Engineering

G. Balaganesan

M. Pushparaja

Ballistics

carbon

Carbon nanotubes

Energy absorption

Glass fibers

Impact testing

Laminates

Nanocomposites

Nanoparticles

Nanotubes

Projectiles

ABSORPTION CHARACTERISTICS

Effect of temperature

ENERGY-ABSORBING CAPACITY

GAS GUN

IMPACT LOADINGS

Residual velocity

TEMPERATURE ENVIRONMENTS

Thermal environment

Laminated composites

Fulltext

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Procedia IUTAM

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

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.

Latin American Journal of Solids and Structures

Modal analysis of pre and post impacted nano composite laminates

Polymer/Clay nanocomposites consisting of an epoxy matrix filled with nanolayered silicate clay particles have been investigated. Recent and ongoing research has shown that dramatic enhancements can be achieved in mechanical and thermal properties by adding a small volume percent of clays. In the present work nanocomposites are processed by mechanical mixing of epoxy with organoclays and unmodified clays using a high speed electric shear mixer at room temperature. The addition of different organoclay wt% [1-3, 5 and 10] indicates good enhancement in hardness, dynamic mechanical properties, and also the molecular mobility of the polymer is reduced by the presence of the silicate layers, which in turn causes large stiffness improvements. X-ray diffraction (XRD) results show the intercalation/exfoliation of clays in the epoxy matrix. The influence of organoclay restricts the weight loss at varying temperatures. Experiments show improved elastic modulus for both modified and unmodified clays.

Journal of Materials Science

Room temperature processing of epoxy-clay nanocomposites

International Journal of Innovative Technology and Exploring Engineering Regular Issue

Vibration Analysis on a Thin Walled Structure

Impact Loading on Nanocomposites in Thermal Environment

Journal	Data powered by TypesetProcedia IUTAM
Publisher	Data powered by TypesetElsevier B.V.
ISSN	22109838
Open Access	No