Experimental study on multi-step creep properties of rat skins

• Published in: Journal of the mechanical behavior of biomedical materials Vol. 46; pp. 49 - 58
• Main Authors: Chen, Gang, Cui, Shibo, You, Lin, Li, Yan, Mei, Yun-Hui, Chen, Xu
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Ltd 01.06.2015
• Subjects: Animals; Biomechanical Phenomena; Creep; Materials Testing; Mechanical Phenomena; Microstructure; Multi-step; Rat skin; Rats; Skin - cytology; Stress, Mechanical; Temperature; Tensile Strength; Weight-Bearing; Creep; Multi-step; Microstructure; Rat skin
• ISSN: 1751-6161; 1878-0180
• DOI: 10.1016/j.jmbbm.2015.02.020

Tension, single-step creep, and multi-step creep of rat skins at room temperature were experimentally studied. We studied the effects of loading histories of high stress creep, low stress creep, and stress relaxation on multi-step creep. Microstructure of rat skins after prescribed tests were observed microscopically with the help of standard hematoxylin and eosin (H&E). The void ratios were also analyzed. The loading histories of high stress creep, low stress creep, and stress relaxation have significant influence on multi-step creep. We found that the creep strain and its rate in the steady-state stage and the creep-fatigue life of rat skins are sensitive to creep stress. Low stress creep after the loading history of high stress creep is characterized as a recovery of strain and a zero strain rate. Both the loading history of low stress creep and stress relaxation act as a recovery in multi-step creep, and they are driven by a same mechanism in the creep strain and the void ratio of rat skins. The loading history, of which sequence is as followings successively: low stress creep, stress relaxation, and high stress creep, helps to obtain the largest creep strain at the lowest void ratio. •Creep strain, strain rate, and life are sensitive to stress.•Strain recovers in low stress creep after a high stress creep history.•Strain rate of low stress creep after high stress creep history becomes zero.•Low stress creep, stress relaxation, then high stress creep reduces void ratio.