单纤维刺扎人体皮肤的弯曲力学行为分析

伸出织物表面的短、粗纤维末梢是产生贴身纺织品针刺感的主要原因,本质是纤维末梢刺扎并诱发皮肤伤害性机械刺激感受器.通常基于固定－铰接约束条件下弹性压杆轴向压缩稳定性理论,计算纤维末梢的临界压力判断这种感受器的诱发可能性.然而,这种方法忽略了织物握持纤维末梢的强度、纤维末梢接触皮肤的滑动阻力及其柔韧性特征.本文以伸出织物表面的直立纤维末梢为对象,假设其织物握持端为线弹性转动约束、另一端受皮肤的接触反作用力和滑动阻力作用,建立纤维末梢刺扎人体皮肤的弯曲变形力学模型.通过参数化模拟,本文比较分析了纤维末梢在弹性－支撑约束和固定－铰接约束条件下的弯曲变形行为.研究发现,纤维末梢在弹性－支撑约束条件下的弯曲力学行为才能解释其刺扎皮肤产生的大多数力学现象及针刺感现象.

Bending mechanical behavior of single fiber prickling human skin

Coarse and short fiber ends protruding above fabric surface mainly contribute to prickiness sensation of next-to-skin clothing,and the delectability of this sensation is usually based the justification on the critical buckling force of single fiber end as a fixed-hinged slender rod under axial compression.The assumption that a fiber end prickling human skin is fixed-hinged,however,can be too simplified to describe the real constraint conditions,both the end prickling human skin and the other end held in fabric.To clarify the role of different constraint conditions in the bending mechanical behavior of single fiber protruding fabric surface and prickling human skin,a coupling fiber-skin model was established to simulate the prickling indentation into skin,where the end against human skin is constrainted by fiber-skin friction and the other end held in fabric surface can rotate with a linear elastic stiffness,and then a parametric analysis on friction coefficient and rotation stiffness was performed.The results show that the elastic-constraint fiber end can subject to a higher axial compression force than the psychophysical threshold of perceived prickliness sensation,and most of published prickliness phenomenon can be explained on the basis of the established fiber-skin model with friction and elastic constraints.