Towards the probabilistic simulation of discontinuous ultra-thin Randomly Oriented Strands: Meso-macro modelling and uncertainty quantification

This study introduces a hierarchical two-scale methodology to effectively simulate the mechanical behaviour of Randomly Oriented Strands (ROS) of ultra-thin discontinuous thermoplastic prepreg tapes. The mesoscopic model accounts for the stochastic morphology of the ROS composites, from which homogenised material properties, such as modulus and strength, are derived and incorporated into an isotropic macroscopic model. A comparative analysis of macro-models with spatially varying inputs versus single sets of inputs demonstrates that homogeneous modelling yields 20% higher accuracy in relation to experimental measurements. Additionally, we outline how this approach enables the application of uncertainty quantification to inform the meso-model about the target mean and standard deviation from experimental observations. The two-scale simulation framework paves the way to virtually analyse large-scale structures made from discontinuous composites by considering mesoscopic material properties.