Failure modes for sandwich beams of GFRP laminate skins and Nomex honeycomb
core are investigated. Theoretical models using honeycomb mechanics and cl
assical beam theory are described. A failure mode map for loading under 3-p
oint bending is constructed, showing the dependence of failure mode and loa
d on the ratio of skin thickness to span length and honeycomb relative dens
ity. Beam specimens are tested in 3-point bending. The experimental data ag
ree satisfactorily with the theoretical predictions. The effect of honeycom
b direction is also examined. The concept of a failure mode map is extended
to give a useful design tool for sandwich panels manufacturers and their c
ustomers. (C) 1999 Elsevier Science Ltd. All rights reserved.