Simple Input Concrete Constitutive Models: An Illustration of Brick Wall & Concrete Cylinder Perforation

Analysts faced with making predictions that involve uncharacterized materials need to bound their results in a rational manner. For concrete materials, LS-DYNA® includes three simple input concrete material models that provide strength envelopes ranging from low, to intermediate, and high strength. Using a range of concrete strengths in numerical simulations is rational when little or no other information about the concrete is available. The typical system response quantity of interest (SRQ) in perforation studies is the exit velocity of the projectile. The simple input concrete models provide a range of concrete resistance to penetration that in turn produces a corresponding range of projectile exit velocities. Quantifying this possible range of exit velocities provides the decision maker with an assessment of what to expect in the field or laboratory for uncharacterized concrete targets. The use of multiple simple input concrete models to provide a range of exit velocities is demonstrated for a simple model of a brick wall, where no experimental data was available. To provide the reader with some indication how this approach can be used to compare predictions with laboratory data, the experimental and numerical results for a set of concrete cylinder perforations is provided.