Failure of flight feathers under uniaxial compression

Area of Science:

• Biomechanics
• Materials Science
• Structural Engineering

Background:

• Flight feathers are complex engineering structures essential for avian locomotion.
• Previous studies focused on bending resistance, but compression-induced failure mechanisms remained less understood.

Purpose of the Study:

• To investigate the failure mechanisms of flight feathers under axial compression.
• To analyze the structural instability and buckling behaviors of feather components.

Main Methods:

• Axial compression tests were performed on the rachis and calamus of dove and pelican feathers.
• Scanning electron microscopy (SEM) was used to observe failure modes and resulting structures.
• Delamination buckling models were employed to calculate critical stress values.

Main Results:

• Both rachis and calamus exhibit failure due to structural instability under compression.
• The rachis demonstrates Euler column-type buckling, while the calamus undergoes progressive folding.
• Key failure mechanisms for the rachis include delamination buckling, cell collapse, and cell densification.

Conclusions:

• Flight feathers are sophisticated thin-walled structures with inherent mechanical adaptations for flight.
• Understanding compression failure is crucial for comprehending feather functionality and structural integrity.
• Experimental and theoretical results show strong agreement, validating the analyzed failure mechanisms.