Co-authors​ :

 - SHUBHAM (INDIA), Chandrasekher YERRAMALLI (INDIA) 

In this study, a comprehensive investigation of the ballistic response of unidirectional (UD) glass-epoxy composite is done experimentally as well as numerically through the integration of the rate-dependent Johnson-Cook (J-C) constitutive model. Leveraging finite element analysis (FEA), this research incorporates a J-C damage model to predict the stress-strain response and failure due to the high-velocity impact of the projectile on the composites. One of the primary reasons for using the J-C constitutive model is its popularity among the commercially available FEA softwares, which can make the whole process of estimating the material performance at a high strain rate or high-velocity impact smooth for the engineers and researchers. In our previous study [1] on the high strain rate response of fiber-reinforced polymer (FRP) composites, it was concluded that the application of the J-C plasticity and damage models that are rate-dependent on both yarn and bulk matrix levels yields a significant enhancement in predicting the peak stress and corresponding strain values when compared to conventional rate-independent models. It is one of the primary motivations for our current study.
This study highlights the crucial role of rate-dependent constitutive models in effectively capturing dynamic responses and failure modes associated with ballistic impact on UD glass-epoxy composites. To validate and enhance the credibility of our numerical predictions, a comparative analysis with 4D x-ray results from experimental trials is conducted, providing a robust framework for assessing the model's predictive capabilities and aligning the simulation outcomes with real-world observations. This integrated approach contributes to advancing both numerical simulations and experimental methodologies in characterizing the intricate ballistic behavior of UD glass-epoxy composites under high-velocity impacts.
While the results are promising, the study also acknowledges the ongoing need for parameter optimization within the J-C model to further enhance accuracy. Future efforts may concentrate on refining these parameters to align numerical predictions more closely with experimental observations. Overall, this research contributes valuable insights into the development of accurate constitutive models, advancing the predictive capabilities for the ballistic response of UD glass-epoxy composites and supporting ongoing efforts in material design and performance optimization under dynamic loading conditions.