SEQUENTIAL MULTISCALE MODELLING OF PARTICULATE AND CARBON FIBRE COMPOSITES CONTAINING SILICA.
Sequential Multiscale, Computational Micromechanics, Hybrid Composites, Carbon Fibre, Silica Microparticles.
Most composite materials are heterogeneous when observed microscopically. However, ordinary finite element analyses of composites do not consider the influence of phases on the mechanical behaviour of the material. This work evaluates different composites using a sequential multiscale methodology, which models each phase with a micromechanical computational analysis of the representative volume element (RVE) and brings the homogenised results to the macroscale. Three types of composites are made with epoxy matrix phase and are classified as silica particle-reinforced polymer (SPRP), carbon fibre-reinforced polymer, and carbon fibre silica particle- reinforced polymer or hybrid. RVE uses a 3D Finite Element (FE), and it is restricted with different boundary conditions. The macroscale represents the geometry of ASTM specimens fabricated for experimental testing with the FEM. A User Material subroutine (UMAT) reproduces the behaviour of micromechanical analyses at the higher scale. Experimental analysis characterise and validate numerical results. In particular, for the SPRP, the results were taken from literature. For fibrous composites, a hand layup method is performed considering the fibre volume fraction of 30%. In addition, the hybrid configuration considers 9wt% of the particles in relation to the total mass of the matrix. Tensile, compression, and in-plane shear tests are performed. Unidirectional laminates are characterised in the longitudinal (0º) and transverse (90º) directions for tensile and compression tests, while a 45º/-45º ply configuration is employed for the shear test. The results show good accuracy for elastic and inelastic responses when compared to experimental and numerical mechanical behaviours. This methodology can support future researches in the same field.