Evaluation of nearly singular integrals in isogeometric boundary element method

Isogeometric boundary element method (IGBEM) is a new numerical method that has received a lot of attentions in recent years. However, nearly singular integrals in the IGBEM have not yet received more attention when the IGBEM is used to study thin-body/coating structures. In this paper, the exponential transformation method based on the idea of diminishing the difference of the orders or the scale of change of addition factors in the denominator of the kernels is used to remove or weaken the near singularities of nearly singular integrals appearing in 2D/3D potential problems. Numerical results show that the present method is effective, stable and competitive. We believe that this work clearly presents the power of the IGBEM and provides an efficient approach to investigate the boundary layer effect appearing in thin-body/coating structures.