In this paper, tensile experiments were performed on the dorsal and ventral skin of rats, and the mechanical properties of the skin in these two sites were compared and analyzed.
A three-factor experimental protocol of site (dorsal and ventral), strain rate (0.71s-1, 7.1×10-3s-1), and sampling orientation (0°, 45° and 90° relative to the spine) was established for tensile test using the L6(31×22) orthogonal table modified from the standard orthogonal table L4 (23). Uniaxial tensile experiments were performed on rat skin samples to calculate the stress-strain curve. The failure strain energy was selected as the index, and the sum of squared deviations of the factors to the index was calculated by analysis of variance (ANOVA), and the contributions of the factors to the failure strain energy were evaluated.
The results showed that the site factor has the largest effect on the tensile strain energy with a contribution of 88.9% and a confidence level of 95%. The strain rate has a small effect on tensile strain energy with a contribution of 10.4% and a confidence level of 90%. Orientation makes almost no contribution to the tensile strain energy. The mean index value of the dorsal skin was 6.492, which was 3.5 times higher than that of the ventral skin. The mean index value of the skin at high strain rates was 4.970, which was 1.5 times higher than that at low strain rates. There was no significant difference in the mean index value among the three orientations.