Session: 03-01-01: Mechanics of Penetration, Shockwaves, and High-Strain-Rate Events: Modeling and Experiments

Paper Number: 94248

94248 - Comparison of Ballistic Impact Simulations Using Different Constitutive Material Models of Concrete 

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 cementitious 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. 

Presenting Author: Chris Duncan Mississippi State University

Presenting Author Biography: Chris is a graduate student in the Department of Mechanical Engineering at Mississippi State University. He received his Bachelor of Science in Mechanical Engineering from Mississippi State University in 2014 and received his Master of Science degree in Civil Engineering from Mississippi State University with a structural engineering concentration. He is pursuing his PhD with a focus on concrete material model development for nonlinear finite element analysis for high strain rate loading. Chris is a registered professional engineer in Mississippi, Tennessee, and Arkansas. After completing his PhD, Chris plans to obtain his structural engineering license in pursuit of career in forensic engineering focusing on failure analysis of structures.

Authors:

Chris Duncan Mississippi State University
Richard Perkins Universities Space Research Association
Daniel Johnson Center for Advanced Vehicular Systems
Mei Chandler U.S. Army Engineer Research and Development Center
Robert Moser US Army Engineering Research and Development Center
Jesse Sherburn U.S. Army Engineer Research and Development Center
Youssef Hammi Mississippi State University