Analytical and Experimental study on FVA of Isotropic and Orthotropic Laminates with FEM Validations

Several approaches such as two-dimensional shear deformation and higher order theories, three-dimensional exact elasticity method and 2-D, 3-D finite element procedures are available in predicting the natural frequencies of composite laminates. In all, a 3-D FEM assists in developing a model for structures with complex constraints, materials and complex geometries. But FE directs an approach that obtains an approximation in solution that depends on discretization type and the polynomials method desirable for field variable limitations. Hence, a convergence test is performed in addition to FE in order to improvise the finite element results accuracy and validating with other benchmark outcomes. The current investigation involves the solving for several boundary conditions of a thick rectangular plate’s free vibration analysis [FVA] for isotropic and orthotropic materials by the application of 3-D finite element methods and convergence results are compared with available analytical results. In addition, experiments are conducted on thick isotropic and orthotropic materials along with experimental modal analysis in order to verify 3-Dimensional finite element process. From this study it can be known that, the values of finite element method highly converges with various experimental and analytical results of isotropic material. When comparing 3-D FEM with the experimental results of the orthotropic sample, a deviation of 5-8% was observed.