Abstract

The vibration behavior of monofilaments was investigated to identify their physical and apparent properties. The investigation is based on the general belief that the modal parameters of a given structure are the functions of its physical properties. Therefore, a laboratory instrument with a high-speed digital camera was designed to measure the vibration behavior of simple monofilaments, knotted monofilaments, two-monofilament samples with no twist, and twisted monofilaments. The vibration was recorded by the high-speed camera at all the points of the strings. Video processing was done to extract the vibration diagrams and to obtain the signal features of the monofilament. Certain physical changes made in the strings affected their signal features. As the results showed, with an increase in the number of knots, the energy parameter would undergo the highest percentage of change; 1.68%, 4.69%, 18.95% and 22.64% changes were recorded for 1, 2, 4 and 8 knots respectively. In addition, an increase in the number of strings and twists could cause the most changes in four-momentum; 57.79%, 29.06%, 2.32% and −18.63% changes were recorded for two-monofilament samples with no twist, 1, 5 and 10 twists respectively. The existence of knots and the increase in the number of monofilaments led to the reduction of the effective frequency but the increase of the damping coefficient. An increase in the number of twists also caused an increase in the effective frequency. The existence of only one twist was associated with a significantly low damping coefficient, but, as the number of twists increased, the damping coefficient increased too. Knot displacement did not affect the effective frequency and the damping coefficient, but the symmetric distribution of the knots reduced the damping coefficient.

摘要

研究了单丝的振动行为，以确定它们的物理和表观特性。调查基于这样一种普遍信念，即给定结构的模态参数是其物理特性的函数。因此，设计了一种带有高速数码相机的实验室仪器来测量简单单丝、打结单丝、无捻的两根单丝样品和扭曲单丝的振动行为。高速摄像机记录了琴弦所有点的振动。进行视频处理以提取振动图并获得单丝的信号特征。琴弦中的某些物理变化影响了它们的信号特征。结果表明，随着节数的增加，能量参数将经历最高百分比的变化；1、2、4 和 8 节分别记录了 1.68%、4.69%、18.95% 和 22.64% 的变化。此外，弦数和捻数的增加可能导致四动量的变化最大；对于没有加捻、1、5 和 10 捻的两根单丝样品，分别记录了 57.79%、29.06%、2.32% 和 -18.63% 的变化。结节的存在和单丝数量的增加导致有效频率降低但阻尼系数增加。捻数的增加也导致有效频率的增加。只有一个捻度的存在与显着低的阻尼系数相关，但是，随着捻度数的增加，阻尼系数也增加。