Wrinkles and folds enable stretching of elephant trunk skin


SOCIETY FOR INTEGRATIVE AND COMPARATIVE BIOLOGY
2021 VIRTUAL ANNUAL MEETING (VAM)
January 3 – Febuary 28, 2021

Meeting Abstract


23-12  Sat Jan 2  Wrinkles and folds enable stretching of elephant trunk skin Fourney, E*; Sukhwani, A; Schulz, A; Hu, D; Georgia Tech, School of Mechanical Engineering, Atlanta, GA; Georgia Tech, School of Mechanical Engineering, Atlanta, GA; Georgia Tech, School of Mechanical Engineering, Atlanta, GA; Georgia Tech, Schools of Mechanical Engineering and Biological Sciences, Atlanta, GA efourney@gatech.edu

To reach objects, the trunk can elongate by 25% of its relaxed length, and this deformation is mostly absorbed in unraveling of wrinkles and folds rather than in stretching the flat patches of skin. In this experimental study, we perform tensile tests on dissected skin from seven different sites along a deceased African elephant (Loxodonta Africana). We find that one wrinkle can absorb 20 percent of the strain, while a fold can absorb 90 percent of the imposed. By inputting the geometry of the wrinkles and folds into finite element simulations, we hope to predict material properties of the skin and rationalize the observed locations of folds and wrinkles. These findings may inform new bio-inspired materials that exhibit a combination of high load bearing capabilities and large axial strains without failure.

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