Concrete is a widely implemented material in simulation codes and understanding its response in different loading scenarios is of interest to researchers. Notably, concrete is an extremely versatile material for many different types of applications due to its ability to withstand high compressive loading conditions at an affordable cost. For this reason, it is of a strong interest to many researchers. Specifically, understanding the response of the concrete materials in ballistic loading conditions is of importance for scenarios such as military and defense applications. Furthermore, computational models have been developed to simulate the response of contentious materials in these loading conditions. In our study, a computational finite element analysis is conducted to evaluate the response of the high strength concrete denoted as BBR9. The mechanical response of this concrete is captured using two constitutive material models denoted as the Concrete Damage and Plasticity Model 2 (CDPM2) and the Holmquist-Johnson-Cook (HJC) concrete model. In this study, the material parameters of these concrete models are calibrated using existing experimental data found in literature. Specifically, confined triaxial compression and uniaxial compressive experiments (for multiple strain rates) are used to determine the parameters which are implemented to define the response of the BBR9 concrete for each material model. These calibrated material models are implemented to conduct finite element simulations to capture the ballistic impact response of the BBR9 concrete. The finite element simulations are conducted using impact velocities ranging from 300m/s to 1300m/s to present a wide ranged assessment of the energy transfer between the projectile and the BBR9 concrete targets due to the impact. Additionally, for our study a BBR9 target thickness of 25.4mm and a simple spherical projectile is considered. A numerical assessment of the material models is presented by comparing the impact velocity against the residual velocity for each simulation point considered in this study. These results present an assessment of the concrete models and also provides a conceptual validation of their responses. The material models are also qualitatively compared through crater and scabbing diameter results of the targets. The CDPM2 model presents scabbing on the front and rear surfaces of the concrete target, while the HJC model shows cratering of the impact site. Additional experimental studies are warranted to assess the response of this concrete under ballistic loads. Further, future experimental studies can be used to validate these finite element constitutive material models in the appropriate referent of the ballistic impacts.

Concrete offers superior strength in compressive loadings and is implemented for many applications. The high compressive strengths enable concrete to resist high strain rate loading scenarios such as ballistic impacts. A variety of concrete denoted as Cor-Tuf, which is classified as ultra-high-performance concrete with a compressive strength of 210 MPa, is evaluated in this study. The response of this concrete is assessed through a finite element analysis under the high strain rate loadings of ballistic impacts. To capture the response of the concrete, a plasticity and damage constitutive model denoted as the HJC model is implemented. The parameters of this model are calibrated to the Cor-Tuf concrete using confined compression experiments, unconfined compression experiments, and shock experiments. The concrete target is impacted at speeds between 610 m/s through 1112 m/s, and the results are compared to existing experimental data. Our results show that the HJC model can predict the response of this impact to the Cor-Tuf concrete targets as an average error of 5.85% is found. The results of this study present parameters which can be implemented with the HJC concrete model for future studies to model the response of the Cor-Tuf UHPC.

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