Analysis of Laminated Composite Plates having Variant Openings

Author Name : Neeraja Nath

ABSTRACT

A composite laminate is an assembly of layers of composite materials stacked in thickness direction which is joined together to provide required engineering properties. The two constituents are reinforcement and a matrix. The study and analysis of the laminated composite plates with cut-outs of different shapes is very essential in order to study about the dynamic behaviour of the structure and its safe design because the fibre orientation, stacking arrangements and material properties influence the response from the laminate. In this study, finite element analysis of laminated composite plates made up of graphite epoxy and carbon aluminium with different fibre orientations and opening shapes was carried out using ANSYS 17.0 software. Shell181 of ANSYS finite element software was used in the design of the plate. The opening shapes considered for the analysis include square and circular shapes and the fibre orientations are 0⁰,30⁰,45⁰and 90^0.Dynamic and buckling analysis were done and the results are compared together to identify the most preferable composite material, shape of opening and fibre orientation.

In the dynamic analysis, frequency responses for free vibration analysis of the plates and deformations were obtained. Similarly, in buckling analysis the critical buckling load values are analyzed in order to obtain the critical buckling stress values of the plates. From the analysis results, graphite epoxy composites have less frequency of vibration and critical buckling stresses but carbon aluminium have lesser deformations. So, the composite plates made of graphite epoxy is found to be more preferable for resisting dynamic and buckling loads. But, carbon aluminium plates are more capable of withstanding higher deformations. Also, it was obtained that the 90 degree fibre orientation is preferable for dynamic loads and 45 degree fibre orientation is suitable for buckling loads. Further, the plates having circular opening resists more deformation but those with square openings resists the buckling of composite plates.