Effect of Cut-Out on Natural Frequency of Laminated Composite Stiffened Plates

The aim of this work is to obtain the natural frequency of laminated composite stiffened plates with cut-outs by experimental and numerical investigation. The experimental natural frequencies are obtained using Fast Fourier Transform (FFT) analyzer and numerical frequencies by applying the Finite Element Method (FEM). The hand layup technique has been considered for the manufacturing of the laminated stiffened composite plates. The influence of various parameters like the location of openings, i.e. eccentric and concentric, size of these cut-outs and variation in eccentricities, angle of orientation of fibers and different support conditions on the natural frequency of square and rectangular stiffened plates has also been investigated. The frequencies obtained from experiment and FEM are in very good agreement. Furthermore, the above factors influence the natural frequencies of the perforated laminated composite stiffened plates enormously. In addition to this, the present research findings will significantly assist the designers in designing the laminated composite stiffened plates accurately.