... 3 (cubic) 3 5 (quintic) Table 3 .5 Gauss point coordinates and weights I [i Wi 1 0.0 2.0 2 0 .57 7 35 , -0 .57 7 35 1.0,1.0 3 0.77 459 , 0.0 , -0 .77 459 0 .55 555 , 0.88888, 0 .55 555 111IiiiIfdWf[[[ ... linear elements (c) one quadratic element 40 The Boundary Element Method with Programming If the element shape functions for the quadratic element are derived from Lagrange polynomials, then there ... equation as follows: (4 .57 ) where x,y is substituted for i,j and (4 .58 ) is the Kronecker Delta. For the boundary element method we also need the solutions for the boundary stresses (tractions)...