Research Objectives and Approaches:
This research is concerned with continuum mechanics modeling of the mechanical behavior of rubber-like materials or soft biological tissues undergoing large strains. The new material models that are developed exhibit severe strain-stiffening at large strains, in contrast to the classical nonlinear elastic models usually employed. Of primary concern are constitutive models that reflect limiting chain extensibility at the molecular level. These have the feature that a stress singularity occurs at the limiting strain and thus capture the abrupt strain-stiffening observed experimentally for non-crystallizing rubber, soft biological tissues and biomaterials. It is proposed to use basic concepts of nonlinear continuum mechanics to model and analyze some fundamental problems for these materials. Particular emphasis is given to fracture, indentation and penetration problems.
Societal Impact :
The work proposed here on the mechanical behavior of rubber and rubber-like materials is of critical importance to the nation?s infrastructure as well as to the automotive, aerospace, defense and bio-technological industries. The research also is applicable to the behavior of biological soft tissues and biomaterials. In industrial practice, large scale commercial finite element computer codes are based primarily on classical models and so their predictions for rubber-like materials at large strains warrant critical reassessment. In particular, fracture, indentation and penetration of elastomers are important current technological areas to which the proposed work will contribute. The work is interdisciplinary involving modern methods of engineering mechanics, physics and applied mathematics. The education of graduate students will contribute to the future science and engineering workforce. Fundamental studies of the type proposed here are necessary to ensure the safe reliable utilization of rubber-like materials and engineered biomaterials in modern technology.
