Although the mechanics of composites in infinitesimal deformation has been extensively studied in the literature, mechanical behavior of composites in finite deformation is still not well understood due to the complexity from the coupling of material nonlinearity and geometrical nonlinearity. In this talk, we will investigate the mechanics of hyperelastic composites, including fiber-reinforced composites and particle-reinforced composites. The first hyperelastic composite we considered is soft tissue, which is usually modeled as fiber-reinforced composites. A phenomenological model is first developed to consider the fiber-matrix shear interaction. Then it is explained by micromechanics theory and the model is improved to a composite-based model.
 
We studied the mechanical response of a particle-reinforced neo-Hookean composite under general finite deformation via a numerical homogenization approach. A representative volume element (RVE) model with periodic microstructure is created to represent the neo-Hookean composite which consists of the neo-Hookean elastomer embedded with randomly distributed equal-sized spherical neo-Hookean particles. Four types of finite deformation (i.e., uniaxial tension, uniaxial compression, simple shear and biaxial deformation) are simulated using this RVE with periodic boundary conditions (PBC) enforced. The simulation results show that the overall mechanical responses of the neo-Hookean composite can be well predicted by another simple neo-Hookean model. If the reinforced particles are aligned as chain-distributed (e.g., magnetorheological elastomer), the particle chain is first treated as a “virtual fiber” and its effective stiffness is obtained using our particle-reinforced composite model. The mechanical behavior of the composite can be predicted by the composite-based model.

Biography

Prof. Zaoyang Guo received his Ph.D. in Engineering Mechanics from Northwestern University (USA). He worked as a lecturer at University of Glasgow (UK) from 2006 to 2010, then as a reader at Newcastle University (UK) from 2010 to 2011. After that, he returned back to China and worked as a professor at Chongqing University in November 2011. He then joined the Institute of Solid Mechanics, Beihang University in July 2014. Prof. Guo’s research interests include mechanics of composites, computational solid mechanics, and biomechanics.