Tensile loading state sensing and estimation of opaque polymer materials using pulsed-terahertz waves

Abstract

In this study, we used pulsed terahertz (THz) spectroscopy to analyze the THz optical properties of opaque acrylonitrile–butadiene–styrene (ABS). The phenomenon occurring upon the propagation of pulsed THz waves through ABS was analyzed through measurements of the variations in THz optical parameters (absorption constant, complex dielectric properties, and refractive index). When tensile loading of 0.1–1.5 kN was applied to a specimen, large optical coefficient variations were observed at 0.275, 0.471, and 0.686 THz, regardless of the applied tensile loading. The optical parameter variations were analyzed at 0.275 THz. Moreover, the accuracy of a tensile loading state estimation model established using principal component analysis was analyzed; consequently, random loading was confirmed. The input factor was extracted and calculated, with an error of approximately 3%, except for small loading (100 N).