engleski

Multiscale Analysis of Aeronautical Composite Structures Using High Fidelity Generalized Method of Cells

The paper deals with the problem of micromechanical failure initiation criteria for complex composite structural components. Heterogeneity of composite materials is the source of numerous failure mechanisms which can develop in fiber reinforced composite materials. This fact has led to the idea of performing failure and damage analyses on the constituent level using micromechanical principles. Computation at the micro-scale has been performed employing a modification of the High Fidelity Generalized Method of Cells (HFGMC), which has been implemented into the finite element code Abaqus/Explicit. The HFGMC model is implemented into Abaqus via the user material subroutine VUMAT. The result of the micromechanical pro-cedure is the computation of strain concentration tensors, which relate the strain tensor at the macro-level to the strain tensor of each subcell. This enables calculation of the stress field within the unit cell, based on the constitutive behavior of each subcell. 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. In order to select an appropriate failure criterion which will initiate damage processes on the subcell level, the most commonly used micromechanical failure criteria have been evaluated against ply-based failure criteria. The HFGMC model has been tested on a relatively simple finite element model, representing a typical structural component of aeronautical structures. Parametric analyses using different unit cell refinement levels have been performed. Results of micromechanical analyses confirm significant discrepancies among the applied failure criteria and dependence on unit cell re-finement.

multiscale analysis; micromechanical model; failure criteria; Abaqus/Explicit

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