Volume no :50, Issue no: 1, March (2018)

COMPUTATION OF SINGULARITIES COEFFICIENTS FOR BILAPLACIAN OPERATOR IN A DOMAIN WITH CORNER

Author's: Cheikh Seck
Pages: [71] - [101]
Received Date: March 14, 2018; Revised April 3, 2018
Submitted by:
DOI: http://dx.doi.org/10.18642/jmsaa_7100121939

Abstract

This work consists on the computation of singularities coefficients in a non convex plane domain. We use a mixed finite element method of class based on a technical characterisation of dual singular functions. Indeed, these coefficients are obtained directly from dual singular functions. The operator which used here is the bilaplacian involved in the problem decomposed in two laplacians and Throughout the discretization, the singular functions are no longer set up on u but on y. In some regularity conditions, the error estimations for the singular coefficients with these hypotheses, give us an error when we use dual singular functions.

Numerical tests with Free-fem++ allowed us to calculate and plot the curves of the coefficients of singularities by direct calculations and approximations using finite elements mixed in the same benchmark. Thus, it follows asymptotically that the gap between the two curves is very small narrows and stabilizes when the mesh becomes more refined.

Keywords

bilaplacian, mixed finite element, singular functions, dual singular functions, error estimations, cracks, simulations, Free-fem++ and Scilab.