فهرست مطالب majid safarabadi farahani

In this paper, high velocity impact behavior of honeycomb structures was modeled by implementing high strain rate dependent properties of honeycomb and its ballistic limit velocities in collision with hemispherical as well as flat ended projectiles were calculated. The obtained results were validated with those available in open literature and numerical ballistic limit velocities were found to be in good agreement with experimental ballistic limit velocities. In addition, ballistic limit velocities in models without strain rate dependent properties were calculated and compared with those in previous models to evaluate the influence of strain rate dependent properties. Comparing the results of these two kinds of models showed that using strain rate dependent properties increases absorbed energy as plastic dissipated and frictional dissipated energies which improve accuracy of numerical modeling significantly. On the other hand, fracture mechanisms and damaged zones were investigated in numerical models and were compared with experimental output. Damaged zones in front of honeycombs in numerical models were similar to experiments but honeycomb manufacturing process and random collision of projectile with honeycomb, made some differences in damaged zone at the back of the honeycombs.