| 著者 |
杉原 怜, 野田 康平, 定近 晋也, 髙田 敦, 中村 健太郎, 水野 洋輔, セット ジイヨン, 山下 真司, 遠藤 玄 |
| 抄録 |
Rope-based mechanisms are widely utilized in elevators, cranes, and ship moorings. At the root
of these are often Euler’s belt theory, in which a rope is wound around a fixed pulley and
frictional force is said to increase exponentially with the winding angle. However, experimental
validation of Euler’s belt theory has been limited due to the difficulty in measuring continuous
tension attenuation when the rope is wound intermittently or multiple times. Moreover, previous
study have reported that intermittent winding reduces the amount of tension attenuation, which
the existing theory cannot explain. In this paper, we employed Brillouin optical
correlation-domain reflectometry (BOCDR) to directly measure the tension distribution along an
optical fiber wound around both a circular pulley and an intermittent pulley, simulating a
situation where the end of a synthetic fiber rope was fixed. First, we compared two types of
belt theories: the conventional Euler’s belt theory and a modified theory that accounted for the
bending stiffness of the belt. Next, we experimentally measured the tension distribution using
BOCDR in the optical fiber wound around both pulleys. When the fixed pulley diameter was D and
the optical fiber diameter was d, our results showed that both belt theories yielded similar
results for a circular pulley with D/d ≥ 35. In addition, we successfully observed the
phenomenon that intermittent winding reduces tension damping. Considering these results, we
proposed a new hypothesis that the observed reduction in tension damping was not due to
intermittent winding, but was due to a small D/d ratio. |