Numerical Simulation of Dynamic Spherical Cavity Expansion for Concrete Materials

Cavity expansion in solid is widely employed in penetration resistance analysis. In order to verify the theory of cavity expansion, based on the three-section constitutive model, a finite element analysis of dynamic spherical cavity expansion process for concrete material was conducted. Simulation results showed that cavity wall expands with a certain corresponding velocity when the expansion pressure exceeds a threshold value, which agrees with the functional relation of cavity expansion theory. Further study indicated that the threshold value of expansion pressure linearly depends on the compressive strength of concrete. The radial stress distribution between cavity wall and elastic wavefront agree with theoretical computation, which adds credibility of the simulation, and shows the physical process of cavity expansion in concrete.