Damping Property of Fabric Bending Vibration

金沢大学人間社会研究域学校教育系
目的 : 最終的には衣服の外観美を客観評価するため, 布の曲げ変形に基づく振動現象について詳細に検討し, 振動減衰特性を表す振動パラメータを見出す.成果 : (1) 布の振動減衰挙動は布の粘弾性抵抗係数が無視でき, 繊維素材, 糸や布の構造にかかわらず, 減衰が初期振幅の約1/5に至るまでは減衰曲線は2段階の直線になる. (2) 振幅が小さい場合, 布の内部摩擦は糸―糸間および繊維―繊維間の摩擦の2つに分けられる. (3) 布の曲げ振動パラメータのうち, 第1段直線部の振幅減衰量△d1は布の純曲げ特性および糸―糸間の摩擦に関連している.第2段直線部の振幅減衰量△d2は糸の構造および繊維―繊維間の摩擦に関連している.第1段階の振動持続時間S1は減衰の主要因摩擦項が糸―糸間の摩擦から繊維―繊維間の摩擦に移行する点を表し, 布の組織や糸一糸間の接触圧力に関連している.布の全体的な曲げ振動持続時間S2は布の純曲げ特性と繊維の集合構造に関連している.In order to evaluate beautiful appearance of clothes objectively at the final end, vibrational phenomena of fabric based on bending deformation are investigated precisely and vibrational parameters which show features of vibrational damping properties of fabric are proposed. Following conclusions were obtained : Bending vibration of fabric damped linearly with time in two steps irrespective of fiber material and yarn and/or fabric structure until the amplitude becomes approximately 1/5 of the initial amplitude. This means viscoelastic effect in the fabric is neglected in the bending vibration. Frictional effect in the fabric can be divided into two parts, namely, inter-yarn friction and inter-fiber friction. In the proposed vibrational parameters, amplitude decreaseand the 1st linear-line, Δ d1 is related to pure bending property and inter-yarn friction. Amplitude decrease at the 2nd linear-line, Δ d2 is concerned with yarn structure and inter-fiber friction. Vibration duration time at the 1st step, S1 is the point at which major frictional effect changes from inter-yarnto inter-fiber friction.Total vibration duration time, S2 is related to pure bending property and fiber assembly structure.