Adaptive simulation of quasibrittle failure

This paper presents an adaptive mesh refinement technique suitable for the resolution of highly localized damage in concrete and other quasibrittle materials. Objectivity of the description of softening is ensured by using regularized material models based on the concept of nonlocal averaging, which is applied to isotropic and anisotropic damage formulations. The distributions of strain and internal variables produced by such regularized models are continuous, which facilitates the projection of information from one finite element mesh onto another. The paper comments on important components of a complete adaptive strategy: the error indicator, refinement rules, mesh generator, transfer operators for the mapping of displacements and internal variables, and consistency recovery. The efficiency of the proposed strategy is illustrated by two examples that treat straight as well as curved crack trajectories.