Investigation on Impact Behavior of Thermoplastic Composites: A Ply-Level Numerical Methodology for Impact-Resistance Design

This study combines experimental characterization and numerical modeling to investigate the impact behavior of aramid fiber–reinforced composites incorporating a thermoplastic polyurethane (TPU) matrix. Low-velocity impact (LVI) tests were performed at impact energies of 10, 20, and 50 J to evaluate the mechanical response and deformation characteristics of laminates with different TPU matrix contents. The experimental results demonstrate the outstanding damage tolerance of these composites, as no severe failures occurred over the wide range of impact energy, which is attributed to the remarkable elastic recovery and resilience of the TPU matrix. To elucidate impact dynamics, a ply-level macro-homogeneous finite element (FE) model was developed and validated against experimental results, showing excellent agreement and predictive accuracy. The results indicate that increasing TPU content significantly enhances the composites' impact stiffness, reducing structural deformation and altering the energy dissipation mechanisms. Furthermore, the influence of TPU content on the laminate's impact tolerance exhibits a linear relationship, facilitating an efficient framework for impact-resistance evaluation and the tailored pre-production design of TPU composites for impact applications. This research offers valuable insights and design guidelines for TPU composites, advancing composite impact engineering and underscoring their strong potential in protective and structural applications.