Vibration analysis and damping characteristics of hybrid composite plate using finite element analysis

Abstract

Hybrid composite is a composite which consists of nanoparticles to enhance the strength as compared to conventional composites. A model has been proposed to determine the elastic properties of hybrid composite. The hybrid composite consists of conventional fiber and nanocomposite as matrix. The first step here is to determine the properties of nanocomposite which is done by using Mori – Tanaka method. The CNTs are considered as cylindrical inclusions in polymer matrix in Mori – Tanaka method. Assuming perfect bonding between carbon fibers and nanocomposite matrix, the effective properties of the hybrid composite has been evaluated using mechanics of materials approach. An 8 noded shell element has been used for the finite element analysis having 5 degrees of freedom each node. A 10 X 10 finite element mesh has been used to model the shell element. The shell coordinates which are in Cartesian form are converted into parametric form using two curvilinear parameters. These parameters are again mapped into isoparametric form. A 16 layered laminate with stacking sequence [0 -45 45 90]2S has been used for vibration analysis of simply supported shell element. The dynamic equations of shell are derived using Hamilton’s principle. As the damping characters of the dynamic system are not available, for further investigation damping ratio of first mode and last active mode are assumed. Using Rayleigh damping the damping ratios of intermediate modes can be calculated. The time decay of the system from maximum amplitude to 5% of the maximum amplitude has been used as a parameter to study various shell structures by varying the volume fraction of CNTs in nanocomposite and by varying carbon fiber volume fraction.