The Measurement of Dynamic Modulus and Energy Losses in Single Textile Filaments Subjected to Forced Longitudinal Vibrations

Abstract

Apparatus and techniques for measuring the dynamic properties of single fibers in the frequency range 1-100 cycles/sec. at 70° F and 65% R.H. are described. For the viscose rayon, acetate rayon, nylon, feather keratin, silk, and polyethylene fibers studied, it was found that the quantities ηω and E were approximately independent of frequency in this range, where η is the internal friction, ω the radian frequency, and E the dynamic modulus. Measured values of the energy dissipated per cycle were found to be proportional to the square of the amplitude, in accordance with the prediction of the simple differential equation of vibration assumed (viscous damping and Hookean elastic reaction). Stress relaxation data were obtained with the same fibers and the results are given. Theoretical interpretation of the results is given in another paper [19].