6. Conclusion
An efficient boundary element analysis approach is presented for solving elastic stress problems with several kinds of variable shear modulus. The radial integration method is used to transform the domain integrals appearing in the stress boundary-domain integral equations into boundary integrals. The radial integral in RIM with several kinds of variable shear modulus is analytically integrated for domain integrals based on the employment of the compactly supported fourth-order spline RBF. The strong singularity involved in the stress integral equation is explicitly removed for the derivation of the analytical expressions. The derived formulation can save computational time considerably in forming non-homogeneous integral coefficients. For the use of the RIBEM to solve other problems [8,16], the final radial integrals can be classified into the evaluation of line integral as shown in Eq. (23), and the integration results Eqs. (24)–(45) can be applied to solve a broad range of engineering problems, not just limited to elastic problems.