Assessment of periodic homogenization-based multiscale computational schemes for quasi-brittle structural failure

New methods for the modeling of structural failure by means of multiscale approaches were recently proposed, in which the structural description involves coarse-scale discontinuities, the behavior of which is fed by representative volume element (RVE) computations. Their main asset consists in identifying the material response, including the failure behavior of the material, from fine-scale material parameters and computations. One of the distinctions between the available approaches relates to the boundary conditions applied on the RVE. The methods based on classical computational homogenization usually make use of periodic boundary conditions. This assumption remains a priori debatable for the localized behavior of quasi-brittle materials. For the particular case of periodic materials (masonry), the level of approximation induced by the periodic assumption is scrutinized here. A new displacement discontinuity-enhanced-scale transition is therefore outlined based on energetic consistency requirements. The corresponding multiscale framework results are compared to complete fine-scale modeling results used as a reference, showing a good agreement in terms of limit load, and in terms of failure mechanisms both at the fine-scale and at the overall structural level. © 2008 by Begell House, Inc.