Data-driven statistical method for the multiscale characterization and modelling of fibre-reinforced composites

  • Ciampaglia, Alberto (Politecnico di Torino)
  • Belingardi, Giovanni (Politecnico di Torino)
  • Paolino, Davide Salvatore (Politecnico di Torino)

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Multiscale analysis of composite laminates allows for predicting the mechanical response of these materials avoiding cumbersome experimental campaigns. The matrix and fibre material properties and the size of the Representative Volume Element (RVE) are the main parameters affecting the accuracy of multiscale models. In this work, an inverse statistical inverse to calibrate micromechanical material parameters from macroscale experiments and 3D reconstruction is proposed. First, glass fibre-reinforced epoxy laminates have been analysed with Computer Tomography (CT), then, the material 3D microstructure has been reconstructed and fibre, matrix, and voids were segmented. Following, tensile tests have been performed on the composite specimen, measuring the surface strains with a Digital Image Correlation (DIC) system. The reconstructed volume, converted to a voxel mesh, has been used to compute the homogenized response of composite by Fast Fourier Transform (FFT) analysis. By comparing the marginal distribution of homogenized material stiffness extracted from DIC data of tensile tests, with the conditioned distribution computed by varying the FFT model parameter, the Young modulus of the epoxy matrix has been statistically characterized. A Representative Volume Element with a stochastic definition of the micromechanical parameters, i.e., Stochastic Volume Element (SVE), calibrated on experimental data is here proposed. A probabilistic multiscale model based on the SVE that propagates the uncertainty from the microscale to the structure level is presented. Finally, a composite structure undergoing buckling is modelled with the probabilistic multiscale method and the results are compared with the deterministic hierarchical multiscale approach.