title: Experimental study on multi-step creep properties of rat skins.
abstract: 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.
authors.affiliation: School of Chemical Engineering and Technology, Tianjin University, Tianjin, China.
authors.forename: Gang
authors.initials: G
authors.lastname: Chen
authors.affiliation: School of Chemical Engineering and Technology, Tianjin University, Tianjin, China.
authors.forename: Shibo
authors.initials: S
authors.lastname: Cui
authors.affiliation: School of Chemical Engineering and Technology, Tianjin University, Tianjin, China.
authors.forename: Lin
authors.initials: L
authors.lastname: You
authors.affiliation: Nursing College, Hebei Medical University, Hebei, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.affiliation: Tianjin Key Laboratory of Advanced Joining Technology, Tianjin University, Tianjin, China; School of Materials Science and Engineering, Tianjin University, Tianjin, China. Electronic address: yunhui@tju.edu.cn.
authors.forename: Yun-Hui
authors.initials: YH
authors.lastname: Mei
authors.affiliation: School of Chemical Engineering and Technology, Tianjin University, Tianjin, China.
authors.forename: Xu
authors.initials: X
authors.lastname: Chen
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D008422:Materials Testing; D055595:Mechanical Phenomena; D051381:Rats; D012867:Skin / Q000166:cytology; D013314:Stress, Mechanical; D013696:Temperature; D013718:Tensile Strength; D016474:Weight-Bearing
keywords: Creep; Microstructure; Multi-step; Rat skin