1. We report the first measurements to be made on the effects of hydration
on the mechanical properties of commercially-prepared duck down feathers. T
ensile tests were performed, to failure, on isolated barbs of down feathers
at 50% RH and with fully-hydrated (wet) feathers.
2. The Young's modulus (stiffness) and ultimate stress (strength) of the fe
athers was higher at 50% RH than when wet. Wet feathers, however, failed at
greater extension than dry feathers. The implications for down feather per
formance and for the use of feathers as a structural material are discussed
.