Paper number 760

EXPERIMENTAL MEASUREMENT AND NUMERICAL PREDICTION OF HAIL ICE IMPACT DAMAGE ON COMPOSITE PANELS

Hyonny Kim and Keith T. Kedward

Department of Mechanical and Environmental Engineering, University of California Santa Barbara, CA, 93106, U.S.A.

Summary

Hail ice impact is a realistic and yet not completely understood threat to exposed composite structures such as aircraft fuselage and wing skins, leading edge surfaces, engine nacelles, and fan blades. To investigate this threat, experiments in which carbon/epoxy composite panels were impacted by ice spheres at high velocity (30 to 200 m/s) were conducted to measure: (i) the impact energy at which damage initiates, and (ii) elastic response of the composite panel resulting from impact. Subsequent numerical analyses were performed of the impacts and were validated through correlation with experimental data. Insights gained from the numerical analyses were used to compose an analytical formula predicting the onset of delamination. This formula, based on a global energy balance, provides a cost effective (i.e. lower number of tests needed) means by which the impact damage resistance of composite structures and of composite material types can be established.

Keywords

ice impact, damage resistance, delamination prediction, dynamic response.