IJSRSET162171 | Received: 02 February 2016 | Accepted: 08 February 2016 | January-February 2016 [(2)1: 282-286] © 2016 IJSRSET | Volume 2 | Issue 1 | Print ISSN : 2395-1990 | Online ISSN : 2394-4099 Themed Section: Engineering and Technology 282 Effect of Unit Cell on Elastic Properties of Fiber Reinforced Polymer Composite Materials CH Sai Krishna 1 , S Suneel Kumar 1 , Siva Bhaskara Rao Devireddy 2 , Anand Babu Kotta *3 1 Department of Mechanical Engineering, Vidya Jyothi Institute of Technology, Hyderabad, Telangana, India 2 Department of Mechanical Engineering, National Institute of Technology, Rourkela, Odisha, India *3 Department of Metallurgical and materials engineering, National Institute of Technology, Rourkela, Odisha, India ABSTRACT The mechanics of fiber reinforced composites are complex due to their anisotropic and heterogeneous characteristics. The present work is to evaluate the material properties of fiber reinforced composites for different volume fractions up to 60%. A numerical homogenization technique based on the finite element analysis (FEA) with unit cell was used to evaluate the material properties of unidirectional Kevlar fiber reinforced Epoxy composite. A three- dimensional single and multiple unit cell micromechanical models have been developed by using ANSYS software. The material properties obtained using the numerical homogenization techniques were compared with different analytical methods like rule of mixture, Halpin-Tsai, and periodic microstructure methods. The effect of volume fraction of fiber on predicted material properties of composite is also studied. Keywords : Fiber composite, finite element analysis, Micromechanics, Unit cell, Volume fraction. I. INTRODUCTION The development and characterization of fiber composite materials are becoming an essential part of present engineered materials because they offer advantages such as strength, stiffness, toughness, high corrosion resistance, high wear resistance, high chemical resistance, reduced cost. Except for the experimental studies, either micro or macro mechanical methods are used to obtain the overall properties of composites [1]. Two different analyses are employed to determine the elastic properties of Kevlar fiber reinforced epoxy composites. One is analytical method and another is numerical techniques. Several models for the prediction of elastic properties of fiber reinforced polymer composites have already been proposed by researchers. Srivastava et al. [2] evaluated the effective material properties of the short fiber composites consist of different shape, size and distribution using numerical homogenization technique. The investigations are carried out to study the influence of various parameters like volume fraction, aspect ratio and particle distribution. Multiple cell modeling of fiber reinforced composites with the presence of interphases is studied by Chin and Liu [3]. Numerical simulations of damage evolution in composites reinforced with single and multi-fibers were presented by Wang et al. [4]. The present study is to evaluate the effect of volume fraction on the elastic properties of unidirectional Kevlar fiber reinforced epoxy composites using single and multiple unit cells by finite element analysis. The numerical results are compared with the well existing analytical methods i.e. rule of mixture, periodic microstructure and Halpin-Tsai methods [5]. II. METHODS AND MATERIAL A. Material The materials are taken for the current study is Kevlar fiber as reinforcement and Epoxy as matrix material. The properties of the constituent materials are as shown in Table 1.By varying the content of reinforcing fibers from 0 to 70% the overall composite material properties are determined.