engleski

Micromechanical damage modelling using a two-scale method for laminated composite structures

Failure mechanisms of fibre reinforced composite structures are closely related to processes within the heterogeneous material. In order to include these processes in numerical simulations, a micromechanical model needs to be coupled with the finite element solution. This two-scale framework has in the current work been achieved using the reformulated High Fidelity Generalized Method of Cells (HFGMC) micromechanical model and the FE code Abaqus/Explicit. The two-sale approach enables calculation of the stress field within the unit cell, based on the constitutive behaviour of each subcell and the unit cell morphology. As the stress distribution is determined for the representative unit cells, calculation of failure criteria and constitutive response of the composite are performed on the micro-level. Damage effects are also being modelled at the micromechanical level. Failure initiation has been predicted using three micromechanical failure criteria found in the literature – the 3D Tsai-Hill model, the Micromechanics of Failure model and the 3D Hashin type strain based failure criterion. Comparison of the implemented criteria showed significant discrepancies among them. Degradation of mechanical properties of the composite material has been introduced to the model using the damage model described in a work by Bednarcyk et. al, 2010. The damage model relies on the 3D Hashin type strain based failure criterion and shows good agreement with experimental results.

multiscale analysis; micromechanical models; damage modelling; laminated composite structures.

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