A local radial basis function collocation method for band structure computation of phononic crystals with scatterers of arbitrary geometry

Abstract

• A new numerical algorithm based on the LRBFCM is proposed. • The stability of the LRBFCM is greatly increased. • The boundary or interface condition of complex geometry can be easily treated. • The improved LRBFCM is applied to the PCs with a scatterer of complex geometry. A numerical algorithm based on the local radial basis function collocation method (LRBFCM) is developed to efficiently compute the derivatives of primary field quantities. Instead of a direct calculation of the derivatives by partial differentiation of the shape functions as in traditional numerical approaches, the derivative calculation in the present work is performed using a simple finite difference scheme with an introduced fictitious node. The developed algorithm is geometrically very flexible and can be easily applied to the continuity and boundary conditions of arbitrary geometries, which require an accurate derivative computation of the primary field quantities. The developed LRBFCM are applied to phononic crystals with scatterers of arbitrary geometry, which has not yet been reported before to the authors’ knowledge. A few examples for anti-plane elastic wave propagation are modelled to validate the developed LRBFCM. A comparison with finite element modelling shows that the present method is efficient and flexible.