Effective Young's Modulus of rigid particles in Gelatin composites

Abstract

In many biological systems, small rigid parts are embedded in deformable tissues to perform different biological functions. This study examines the effects of adding rigid filler particles inside deformable material. More specifically, a series of experiments led to eventual understanding of the relationship between effective Young's Modulus of material and volume fraction of rigid particles. The deformable material used in this study is gelatin, a readily available consumer product. It was found that the higher the volume fraction, the higher the Young's Modulus value for the composite material. In addition, it was found that cyclic loading with high strain and high volume fraction may cause stress stiffening or stress softening, while cyclic loading with small strain and small volume fraction yields linear elastic behavior. Furthermore, the effect of strain rate on material behavior was examined. Unfortunately the sample size was too small to draw definite conclusion. Finally, the reusability of particles was explored, and the results suggested that particles in composites are reusable so long as the composite did not undergo high strain compression.