Isogeometric Boundary Element Analysis with elasto-plastic inclusions. Part 2: 3-D problems

A novel approach is presented for the isogeometric Boundary Element analysis of domains that contain predefine dinclusions with material properties that are different to the rest of the domain and which also may exhibit inelastic behavior. The paper is complementary to a paper published recently in this journal, which focused on plane problems. The theoretical framework and implementation are extended to three-dimensional problems here. In our approach the geometry of inclusions is described using NURBS surfaces. The advantage over currently used methods is that no discretization into cells is required, in order to evaluate the arising volume integrals. The implementation is verifie do ntest cases by comparison with either exact solutions or ones computed by the Finite Element method.