Multiscale modelling of scaling effects in the impact response of plain woven composites

This paper presents a multiscale model developed to predict scaling effects in plain woven carbon fibre-reinforced polymer (CFRP) composites. The model contains a parameter-segmented unit cell (UC) developed to account for the contribution of the fabric architecture to the macroscopic response. The behaviour of constituent materials was considered by employing the models that have been established for characterising the nonlinearity and rate-dependence of the polymer matrix and the damage of the yarn material. A user subroutine was developed to numerically implement the parameterised UC and the material models for multiscale analyses. Based on the multiscale model, numerical examples were performed to investigate scaling effects in the impact response of a plain woven composite by simulating scaled panels subjected to projectile impact. It is shown that the proposed model is capable of predicting both scalable and non-scalable effects in this composite with reasonable success. The simulation results highlighted an evident variation of the load-displacement curves with scale size at the post-elastic stage, insensitivities of the primary failure modes and their appearance to scale size, as well as a clear trend of increased capability of energy absorption with scale size, which all agree well with those observed in experiments. The significance of this research is the development of a numerical tool capable of capturing the influence of microscopic features on macroscopic scaling effects in plain woven composites.