A non-intrusive global/local algorithm with non-matching interface: Derivation and numerical validation

• A non-intrusive global/local algorithm is proposed to treat local nonlinearity.
• The incompatible interface data transfer method is robust during iterations.
• The proposed algorithm is verified on 2D and 3D models.
• Different interface geometries and interface node allocations are studied.
• The effect of reduced integration on convergence is concerned.

A non-intrusive global/local algorithm with non-matching (incompatible) interface is proposed to evaluate the durability of large-scale structures with local nonlinearity both on the basis of local multigrid strategy and the domain decomposition (DD) method, which can serve as an intermediate way to perform analyses of complex structures. The proposed algorithm couples a global linear elastic analysis (on coarse mesh) with a local nonlinear analysis (on fine mesh), which extends the iterative global/local method to treat non-matching partition interfaces. Furthermore, to deal with non-matching interface the framework of localized Lagrange multiplier (LLM) method is introduced, and a feasible but robust data transfer method is established with radial basis function (RBF) interpolation. Aitken’s acceleration method is adopted to increase the convergence rate. The convergence property and accuracy of this non-intrusive algorithm are investigated for a two-dimensional model with different interface geometries and interface node allocations. The effect of reduced integration on the convergence rate is also concerned in verification. Then, it is further verified with a three-dimensional model. Numerical results reveal that this non-intrusive algorithm is robust in the non-matching interface data transfer procedure, which is significant in error control during iterations, and it has good performance in both convergence and accuracy.