Cubature rules based on bivariate spline quasi-interpolation for weakly singular integrals

TL;DR

This paper introduces a novel class of cubature rules leveraging bivariate spline quasi-interpolation to accurately compute weakly singular double integrals, particularly those arising in boundary integral equations for 3D Laplace problems.

Contribution

The paper develops a new cubature rule based on spline quasi-interpolation and extends spline product algorithms to the bivariate case for efficient integration.

Findings

High accuracy in integrating weakly singular integrals

Effective handling of boundary integral equations in 3D Laplace problems

Enhanced computational efficiency through local spline quasi-interpolation

Abstract

In this paper we present a new class of cubature rules with the aim of accurately integrating weakly singular double integrals. In particular we focus on those integrals coming from the discretization of Boundary Integral Equations for 3D Laplace boundary value problems, using a collocation method within the Isogeometric Analysis paradigm. In such setting the regular part of the integrand can be defined as the product of a tensor product B-spline and a general function. The rules are derived by using first the spline quasi-interpolation approach to approximate such function and then the extension of a well known algorithm for spline product to the bivariate setting. In this way efficiency is ensured, since the locality of any spline quasi-interpolation scheme is combined with the capability of an ad--hoc treatment of the B-spline factor. The numerical integration is performed on the whole support of the B-spline factor by exploiting inter-element continuity of the integrands