Abstract
By means of torsion pendulum oscillation measurement, one can establish the shear elasticitymodulus and the viscosity of human hair, and enrich the number of material parameters determined for this material that way. While from the tensile curve the tensile elasticity modulus of the hair is commonly determined and the Poisson ratio can be evaluated by optical methods while tearing, by measuring of the self-sustained oscillations one can effectively determine also their shear elasticity modulus and solid-state dynamic viscosity.
This all, in accordance with other authors, assuming homogeneity and isotropy of the hair fibre. Although, from the dependence of the elasticity modulus on the hair diameter, reasonable estimate about the cortex thickness can be done and unravel the knowledge of its modulus and the one of the cuticula.