Modification of the critical projectile diameter of honeycomb sandwich panel considering the channeling effect in hypervelocity impact

In this paper, a variation of the critical projectile diameter of honeycomb sandwich panel (HC/SP), due to the channeling effect, is investigated by using smoothed particle hydrodynamics (SPH). Before performing numerical study on the channeling effect, the results of 2-D hypervelocity impact simulation were compared with the experimental results in order to validate the simulation along with searching proper simulation parameters such as equation of state, strength model, and failure model. And then, analysis of the channeling effect is performed with different cell sizes, wall thicknesses and depths of HC core in accordance with the specifications of commercial HC cores. As a result of the study, it is revealed that the HC core cell size is the most influential parameter on the channeling at normal incidence impact. Also the critical projectile diameter appears to be varying with the HC core cell size due to the channeling effect. Finally, the modified critical projectile diameters of HC/SP are presented by introducing the decrement of critical projectile diameter.