Author(s)

B. Natalini & V. Popov

Abstract

Improved calculation of higher order partial derivatives in the DRM B. ~atalini' & V. popov2 I Fucultad de Ingenieria, Universidad Nacional del Nordeste, Argentina 2 Wessex Institute of Technology, UK Abstract A ncw way of representing partial derivatives (PDs) in the DRM is proposed. This formulation can be implemented only for corner nodes where two boundary elcmcnts join under angle different from n. The new formulation reduces the order of the PDs of thc DRM approximation function by one in respect to the order of the approximated PDs. In this way the introduction of the singularities at the nodes due to differentiation of the DRM approximation function can be avoided.A number of non-linear case studics are shown where different DRM approximations are used for first and second order partial derivatives using four different radial basis functions and four different formulations for partial derivatives. In all cascs whcrc sccond order derivatives were involved the new formulation was the onl

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