1Student (M.Tech), Department of Mechanical Engineering, Prasad V Potluri Siddhartha Institute of Technology, Vijayawada, India
2Assistant professor, Department of Mechanical Engineering, Prasad V Potluri Siddhartha Institute of Technology, Vijayawada, India
Online published on 20 July, 2015.
Natural frequency of any structure is an important property, which is considered while mounting any instruments and/or machines on the structure in order to avoid the possibility of resonance. The natural frequency of a structure depends up on the mass and stiffness of the structure. The material Young’s modulus and the arrangement of constraints influence the stiffness of the structure.
The finite element method is useful in modeling the structures where complex geometries, materials and constraints. But finite element approach gives an approximate solution depending upon the type of discretization and the method of polynomials eligible for field variable. Therefore it is required to conduct convergence test to improve the accuracy of the finite element results.
In the present investigation, free vibration analysis of thin and thick rectangular plates of isotropic materials under various boundary conditions is found using finite element method. In addition experiments are conducted on thin and thick metallic plates to validate FEM with experimental modal analysis also. The finite element models (FEM) which use the elasticity theory for the determination of stiffness matrices are modeled in ANSYS software to evaluate first five natural frequencies of the laminate. The variation of natural frequencies with respect to various isotropic materials like brass, copper, stainless steel and aluminum is presented.
Free vibration, natural frequencies, isotropic materials, finite element method, modal analysis
