engleski

Two-scale damage model for quasi-brittle heterogeneous materials

In this contribution, an existing two-scale model employing the nonlocal strain gradient theory at both micro- and macrolevel is extended and transformed to the analysis of the softening materials. The discretization of both levels is performed by means of the C1 continuity triangular finite elements. The damage model, based on the strain gradient continuum with an exponential evolution law describing the softening of quasi-brittle materials, is implemented at the RVE level. Two separate analyses are performed there, one for the undamaged bulk, where the stress and constitutive operators are extracted using the conventional homogenization, and the other one for the softening material, where the localization is captured by a novel approach. Herein, the damage variable is homogenized only over a loading zone where softening is progressing. Since a linear-elastic material is used, the bulk constitutive operators re-main unchanged throughout the analysis and therefore can be computed only once. The degradation of the macroscale stiffness is governed by the isotropic damage law employing the homogenized damage variable.

Quasi-brittle damage, Homogenization, Multiscale analysis

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