Differences and Similarities in the Mechanical Response of Soft Living Animal Tissue and Filled Polymeric Materials

Abstract

The dynamic morphological response in strip biaxial deformation of a particular soft living animal tissue (cat's mesentery) has been determined by simultaneous mechanical measurements and in vivo histological observation. Similar stress-stretch measurements have been made for glass-bead filled styrene-butadiene rubber in cycles of constant rates of loading and unloading. Both the living and the synthetic specimens exhibit considerable hysteresis accompany such deformations; however, the two materials exhibit different abilities to reheal or recover following loading. In the living tissue, where strong links exist between the ground substance matrix and reinforcing filler material (collagen fibers), consequent stress gradients visible in polarized light develop as the material is deformed, and also microfailure presumably of hydrogen and salt-like bonds occurs as the deformation increases. Likewise, on the micro-scale the glass-bead filled systems show a dewetting of the matrix and the simultaneous formation of conical voids about the glass beads as the specimen is stretched.