MATHEMATICAL ANALYSIS AND TREATMENT FOR THE TRUE AND SPURIOUS EIGENEQUATIONS OF CIRCULAR PLATES BY THE MESHLESS METHOD USING RADIAL BASIS FUNCTION

In this paper, a meshless method for solving the eigenproblems of plate vibration using the radial basis function (RBF) is proposed. By employing the RBF in the imaginary-part fundamental solution, spurious eigenequations in conjunction with the true ones are obtained at the same time. Mathematical analysis for the appearance of Spurious eigenequations by using degenerate kernel and circulant is done through a circular plate for a discrete system. In order to obtain the true and spurious eigenequations, six (C-2(4)) formulations (either two combinations from the four types of potentials, single. double, triple and quadruple) of meshless methods are employed in conjunction with the SVD technique. The spurious eigenequation in each formulation is found and is filtered Out by using the SVD updating technique. Three cases, clamped, simply-supported and free circular plates, are demonstrated to check the validity of the meshless methods.