Department of Mechanical Engineering, Michigan State University, 428 S. Shaw Lane Room 2463, East Lansing, MI, 48824, USA.
School of Mechanical and Material Engineering, University College Dublin, Dublin, Ireland.
Biomech Model Mechanobiol. 2020 Feb;19(1):275-289. doi: 10.1007/s10237-019-01210-9. Epub 2019 Aug 8.
This study investigates the link between the mechanical properties of skin and its microstructural characteristics. Rat back skin samples from different locations, orientations, and sexes were collected and subjected to quasi-static uniaxial tensile tests. Stress-stretch behavior at low stress ranges and rupture data at high stress ranges were collected. The influence of location, orientation, and sex on skin mechanical properties was examined by comparing the mechanical parameters (i.e., initial slope, maximum slope, ultimate tensile strength, rupture stretch, and toughness) evaluated from the tensile testing data. Location and orientation were both found to have a significant effect on the mechanical properties. Collagen structural data (i.e., fiber orientation distribution, relative content, and fiber straightness) were evaluated using histology images. It was found that the rat lower (caudal) back had higher relative collagen content when compared to the upper (cranial) back. A microstructurally based constitutive model was proposed to describe the mechanical behavior of preconditioned rat back skin. The constitutive model incorporated the distribution of collagen fiber bundle orientations and relative collagen content measured from histology, and showed good agreement with the tensile test data. The influence of location and orientation was also evident in the optimized constitutive parameters. This study was a comprehensive investigation that combines skin mechanical behavior, micro-structure, and constitutive modeling.
本研究探讨了皮肤的力学性能与其微观结构特征之间的关系。从不同部位、方位和性别的大鼠背部皮肤采集样本，并进行准静态单轴拉伸试验。收集低应力范围的应力-应变行为和高应力范围的破坏数据。通过比较从拉伸试验数据评估的力学参数（即初始斜率、最大斜率、极限拉伸强度、破坏拉伸和韧性），研究了位置、方位和性别对皮肤力学性能的影响。位置和方位都对力学性能有显著影响。使用组织学图像评估胶原结构数据（即纤维取向分布、相对含量和纤维直度）。与上背部（颅侧）相比，发现大鼠下背部（尾侧）的相对胶原含量更高。提出了一个基于微观结构的本构模型来描述预处理大鼠背部皮肤的力学行为。该本构模型结合了组织学测量的胶原纤维束取向分布和相对胶原含量，并与拉伸试验数据吻合良好。位置和方位的影响在优化的本构参数中也很明显。本研究是一项综合研究，结合了皮肤力学行为、微观结构和本构建模。
