Research on the impact response and chaos characteristics in the dynamic damage evolution process of concrete material

The impact response of concrete material under different dynamic loading conditions (single impact loading with different velocity and cyclic impact loading with different amplitude) have been tested and analyzed by split Hopkinson bar (SHPB) equipment, and the chaos characteristics of sample damage evolution process have also been discussed. Experimental results show that the mechanical properties of concrete samples show obvious strain rate effect, the peak stress increased by 750% with the single impact loading pressure increases from 0.2 MPa to 0.7 MPa. With the increase of the cyclic loading amplitude, the loading times and strain value of the sample decrease when the macroscopic failure occurs. Furthermore, it can be found that the process of dynamic response of concrete sample has experienced stable state, periodic state and chaotic state three stages in the process of damage evolution; the phase proportion of the stable state and the periodic state display negative correlation as the increase of the loading velocity (or the increase of the cyclic amplitude), conversely, the phase proportion of the chaotic state display positive correlation. (C) 2020 Elsevier Ltd. All rights reserved.