Çatlaklı kompozit plakaların dinamik kararlılığı

In recent decades, composite plates are widely used in a wide variety of engineering applications such as the automotive industry, aerospace, marine, rail vehicles and civil engineering structures. Composite plates are subjected to static and dynamic loads. In this study, the dynamic stability of cracked composite plates has been investigated numerically by using the finite element method. Isotropic thin plate based on the Kirchhoff's thin plate theory is modelled by using the principles of the finite element method. In addition to, a composite plate based on classical lamination theory is modelled by using the finite element method. It is assumed that the boundary condition of the thin plate is fixed on one side and the other sides are free. The thin plate is divided into square plate elements. These square plates have four nodes and each node have one translational and two rotational degrees of freedom, so these square plates have twelve degrees of freedom. Mathieu-Hill type motion equation which is used to calculate the dynamic stability of the plate, is created by using energy expressions obtained from the Lagrange equation. The developed MATLAB finite element code is used to examine the effect of crack on natural frequency, critical buckling load and dynamic stability for isotropic and composite plates. Furthermore, MATLAB results are compared with the results of ANSYS model and very good agreement between these results is observed.