A non-intrusive multiscale framework for 2D analysis of local features by GFEM - A thorough parameter investigation

This work comprehensively investigates key parameters associated with a recently proposed non-intrusive coupling strategy for multiscale structural problems. The IGL-GFEM(gl) combines the Iterative Global Local Method and the Generalized Finite Element Method with global-local enrichment, GFEM(gl). Different scales of the problem are solved using distinct finite element codes: the commercial software Abaqus and a research in-house code. An Iterative Global-Local non-intrusive algorithm is employed to couple the solutions provided by the two solvers, with the process accelerated by Aitken's relaxation. Slight modifications have been introduced, and the resulting accuracy and computational performance are discussed using numerical examples. The problems investigated explore the coupling strategy within the context of 2D linear elastic problems, which include voids and crack propagation described at the local scale solved by the in-house code. A noteworthy trade-off between reducing iterations and increasing the time to solve the local problems is observed. Despite the high accuracy achieved, the two versions of the coupling strategy, namely the monolithic and staggered algorithms, exhibit different computational performances when the GFEM(gl) parameters, such as the number of global-local cycles and the size of the buffer zone, are evaluated for the crack propagation simulation.