Mechanical Properties of a Human Eardrum at High Strain Rates After Exposure to Blast Waves

Abstract

The mechanical properties of a human tympanic membrane (TM) or eardrum were characterized at high strain rates after multiple exposures to blast waves. Human cadaveric temporal bones were subjected to blast waves at first, then TM strip specimens were prepared either along the radial or the circumferential direction. A highly sensitive miniature split Hopkinson tension bar was used for tensile experiments on the human eardrum strip specimens at high strain rates. The mechanical properties of the human TMs before and after exposure to blast waves were compared and discussed. The mechanical properties in the time-domain were subsequently converted to the corresponding properties in the frequency domain to investigate the effect of blast waves on the viscoelastic properties. The results indicate that the blast waves have different effects on the mechanical properties in the radial and circumferential directions. After exposure to the overpressure induced by the blast waves, the mechanical behavior in the radial direction in general becomes stiffened, while it is weakened in the circumferential direction. The results could be analyzed further in an ear simulation model to develop understanding of the effect of blast waves on hearing loss.