Effective multiscale structural analysis of thick sandwich structures with 3D woven composite face sheets and a soft core based on coupled micromechanics and refined zigzag theory

In this study, a novel multiscale analysis technique is presented for predicting the mechanical behavior of 3D woven composites. To this end, the model of the representative unit cell (RUC) is generated using SOLIDWORKS computer -aided design package by taking the optical microscopic images as a reference. The fiber volume fractions (FVF) of the impregnated yarns are calculated using the roving parameters and the dry fiber density for each tow separately. Homogenized properties are obtained by utilizing the finite element analysis (FEM) software ABAQUS. The proposed method simplifies the meso -modeling process of 3D woven composites as it does not require CT scanning for geometry generation or sophisticated localized fiber volume fraction measurements. The verification of the current model is carried out both in the meso scale where the RUC surface strains are compared with DIC results and in the macro scale where tensile and flexural tests are simulated and compared with the experiments. Finally, the applicability of this method is demonstrated through an assessment study of the 3D woven composites as facesheets in thick sandwich structures in an isogeometric refined zigzag framework.