Biodegradable composites are highly encouraged to replace the traditional composites to promote the frangibility and environmental sustainability. In this paper, impact response of natural fiber reinforced composites is carried out by using drop mass set-up. Sisal and coir fibers are reinforced in epoxy matrix and the laminates are made by compression moulding process. Experiments are conducted to predict energy absorption and peak contact force during impact of 6 kg mass. Results are analyzed to find suitability of natural fiber reinforced composites in order to derive the suitable materials for frangibility application. © 2017 Trans Tech Publications, Switzerland.

R. Velmurugan

Department of Aerospace Engineering

G. Balaganesan

Fiber reinforced plastics

Fibers

Laminated composites

NATURAL FIBERS

Plasticity

Reinforced plastics

Reinforcement

Sustainable development

BIODEGRADABLE COMPOSITES

Damage

Environmental sustainability

FRANGIBILITY

IMPACT LOADINGS

Impact Response

NATURAL FIBER COMPOSITES

NATURAL FIBER REINFORCED COMPOSITES

Fiber reinforced materials

Biodegradation

Compression molding

Laminates

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

Key Engineering Materials

This paper investigates the influence of homogenous and super hybrid external patches based on plain weave woven glass fabric and aluminium alloy sheet (2024) on low velocity impact and quasi-static tensile after impact (TAI) response of adhesively bonded external patch repairs in damaged glass/epoxy composite laminates. The intent of using super hybrid external patches is to combine the excellent high displacement to failure property of aluminium as a ductile reinforcement with the superior mechanical property of glass fiber as a brittle reinforcement. The undamaged normal specimens were taken as the standard specimen for evaluation of residual mechanical properties. Four various types of external patches with different contents of glass (100%, 50% with two different lay-up configuration, and 0%) were used for performing the repair. In all hybrid patches, the proportion of aluminium and glass fiber were equal (i.e. 50% of aluminium and 50% of glass by volume fraction), while lay-up configuration were different. This further allows studying the associated effects of hybridization and lay-up configuration on low velocity impact and TAI response of the repaired laminates. The effect of glass/aluminium content on impact response and TAI response was investigated at various nominal impact energy levels, namely 2, 4, 6 and 8 J. Results show that super hybridization and lay-up configurations of the external patches play a significant role on low velocity impact and post impact response (i.e. absorbed energy, peak contact force, ultimate load, stiffness, residual deformation, displacement to failure and damage pattern) of the repaired specimens. Results indicate that repaired specimens having external patches with outer layer of aluminium and inner layer of glass fiber exhibited better impact properties and damage tolerance capability than that of the specimens conventionally repaired using homogeneous glass patches. Damage profile analysis was in a good correlation with the experimental results. © 2017 Elsevier Ltd

Composite Structures

The role of adhesively bonded super hybrid external patches on the impact and post-impact response of repaired glass/epoxy composite laminates

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

Experimental study of the impactor mass effect on the low velocity impact of carbon/epoxy woven laminates

Polymer Testing

Effect of fiber surface treatments on the essential work of fracture of HDPE-continuous henequen fiber-reinforced composites

Composites Part B: Engineering

A review on the tensile properties of natural fiber reinforced polymer composites

i-manager's Journal on Future Engineering and Technology

An Efficient Design Technique for High Performance AMBA SoC Design

Frangibility study of natural fiber reinforced composite laminates

Journal	Key Engineering Materials
Publisher	Trans Tech Publications Ltd
ISSN	10139826
Open Access	No