Macro-Micro Deformation Mechanisms of Polycarbonate under High-Strain-Rate Compression: Insights from Multiscale Simulation and Microstructural Characterization

Polycarbonate (PC) is widely used in impact-resistant transparent components due to its excellent toughness and optical properties. However, its mechanical behavior under high strain rate loading remains insufficiently understood, particularly from a microstructural perspective. In this study, the macro-micro deformation mechanisms of PC under high strain rate compression were systematically investigated through an integrated approach combining multiscale simulations and microstructural characterization. Two PC grades with different molecular weights were subjected to dynamic compression experiments using a split Hopkinson pressure bar at high strain rates (4500, 5500, and 7000 s–1) and temperatures of 233, 296, and 353 K. The results reveal pronounced strain rate and temperature dependence in yield stress, yield strain, strain hardening, and unloading strain. Two-dimensional wide-angle X-ray diffraction and polarized Fourier-transform infrared analyzes demonstrate that molecular chain orientation is significantly enhanced under high strain rate loading, with lower molecular weight PC exhibiting more pronounced strain hardening due to easier chain alignment. Molecular dynamics simulations further elucidate that higher molecular weight PC possesses greater conformational stability and resistance to compression. Additionally, the DSGZ model parameters of different PC was calibrated, and accurately predicting the high strain rate compressive response in finite element simulations. The findings provide deep insights into the microstructural origins of the macroscopic mechanical behavior of PC under high-strain-rate compression, offering valuable guidance for material design and engineering applications.