Three-dimensional modelling of steel fiber reinforced concrete material under intense dynamic loading

摘要

This paper presents a new three-dimensional numerical model to study the dynamic response and failure mode of steel fiber reinforced concrete (SFRC) material under impact and blast loading. In the 3D numerical model, SFRC is assumed to be composed of two components, that is, the homogeneous concrete matrix with lower strength and the steel fibers with higher strength. The straight round steel fibers are assumed to be dispersed with random locations and orientations in the matrix and a 3D grid algorithm is introduced to generate the finite element analysis model. The interaction between fibers and matrix is modeled by the bonding and sliding contact algorithm. The mechanical behavior of SFRC material is simulated and a good agreement with the test data is observed. The verified numerical model is then employed to perform a series simulation of split Hopkinson pressure bar (SHPB) and split Hopkinson tensile bar (SHTB) in order to study the dynamic increase factor (DIF) of SFRC material with different fiber volume percentage (V_f) under high strain rate loading. And the influence of V_f on the dynamic properties of SFRC is analyzed. Further numerical studies of the SFRC specimens under contact detonation are carried out and compared with the test data. The result shows that the developed numerical model for SFRC could precisely predict the failure mode.