SMOOTH MODELLING OF THE NORMAL VECTOR BY USING C0-CONTINUOUS LAGRANGE ELEMENTS IN BEM.

The paper reveals the conditions under which the approximations of the normal vector and global coordinates of interior points of two segments on a smooth contour can fail using the C¹-continuous Overhauser elements. A new continuous modelling of the normal vector is developed using the standard Lagrange elements. The derivation is consistent with the assumptions employed in the boundary element method formulations of potential problems. Test numerical examples are considered in order to analyse the accuracy of the approximations based on the use of standard C0-continuous elements, Overhauser C1-continuous elements and the proposed 'smooth' C0 elements. [ABSTRACT FROM AUTHOR]