Study on low energy impact resistance of two kinds of star-shaped honeycomb sandwich panels

In order to study the low energy impact resistance of re-entrant star-shaped (RES) and re-entrant circular star-shaped (RECS) honeycomb sandwich panels with negative Poisson's ratio, the finite element model of honeycomb sandwich panels with composite laminates and ABS honeycomb was established by commercial software ANSYS/LS-DYNA. The impact response of composite sandwich panels with RES honeycomb and RECS honeycomb is analyzed numerically at low impact energies of 10J,15J and 30J. In this paper, impactor displacement versus time curves, contact force versus time curves and energy absorption ratio of sandwich panels under different impact conditions are analyzed and compared. The simulation results show that under the same impact conditions, the damage depth of RECS honeycomb sandwich panels is greater than that of RES honeycomb sandwich panels, and the difference is more obvious when under in-plane impact. In addition, the impactor has a lower rebound speed after impacting RECS honeycomb sandwich panels, that is, the RECS honeycomb sandwich panels has a higher energy absorption ratio. According to the above results, it is concluded that RES honeycomb sandwich panel has better low energy impact resistance than RECS honeycomb sandwich panel, but the latter has better energy absorption performance.