Comparative Study of Progressive Collapse Behavior of Auxetic Concrete Cellular Structures Under Low-Velocity Impact Loading.

The combination of auxetic behavior with concrete offers promising advancements in structural materials, providing unique mechanical properties that enhance impact resistance and energy absorption. The study investigates the mechanical behavior of auxetic concrete cellular structures, focusing on elliptic and peanut-shaped unit cells as well as their modified stiffener configurations, under low-velocity impact loading. To compare their impact performance, traditional and stiffened models were analyzed numerically using finite element solver ANSYS/LS-DYNA. The findings indicate significant differences between traditional and stiffened models. Stiffened models, such as SEC and SPC, exhibit higher maximum impact forces compared to traditional models like TEC and TPC. The introduction of stiffeners delays the zero-force phenomenon, resulting in extended energy absorption periods. The TPC model absorbed the most significant proportion of the initial impact velocity among traditional models, whereas the SPC model exhibited the highest energy absorption in models with stiffeners. The study highlights the potential of stiffened auxetic concrete cellular structures to enhance impact resistance and energy dissipation, making them advantageous for applications requiring high structural resilience. Further research into varying impact velocities and loading directions is recommended to optimize these structures for diverse conditions. [ABSTRACT FROM AUTHOR]