TY - JOUR N2 - The paper presents a tool for accurate evaluation of high field concentrations near singular lines, such as contours of cracks, notches and grains intersections, in 3D problems solved the BEM. Two types of boundary elements, accounting for singularities, are considered: (i) edge elements, which adjoin a singular line, and (ii) intermediate elements, which while not adjoining the line, are still under strong influence of the singularity. An efficient method to evaluate the influence coefficients and the field intensity factors is suggested for the both types of the elements. The method avoids time expensive numerical evaluation of singular and hypersingular integrals over the element surface by reduction to 1D integrals. The method being general, its details are explained by considering a representative examples for elasticity problems for a piece-wise homogeneous medium with cracks, inclusions and pores. Numerical examples for plane elements illustrate the exposition. The method can be extended for curvilinear elements. L1 - http://www.czasopisma.pan.pl/Content/109459/PDF/08_069-076_00811_Bpast.No.67-1_06.02.20.pdf L2 - http://www.czasopisma.pan.pl/Content/109459 PY - 2019 IS - No. 1 EP - 76 DO - 10.24425/bpas.2019.125435 KW - boundary integral equation KW - boundary element method KW - singular element KW - Hadamard finite part integral A1 - Rybarska-Rusinek, L. VL - 67 DA - 28.02.2019 T1 - On evaluation of influence coefficients for edge and intermediate boundary elements in 3D problems involving strong field concentrations SP - 69 UR - http://www.czasopisma.pan.pl/dlibra/publication/edition/109459 T2 - Bulletin of the Polish Academy of Sciences Technical Sciences ER -