  The mechanical response, serviceability, and load bearing capacity of
materials and structural components can be adversely affected due to external
stimuli, which include exposure to a corrosive chemical species, high
temperatures, temperature fluctuations (i.e., freezing-thawing), cyclic
mechanical loading, just to name a few. It is, therefore, of paramount
importance in several branches of engineering -- ranging from aerospace
engineering, civil engineering to biomedical engineering -- to have a
fundamental understanding of degradation of materials, as the materials in
these applications are often subjected to adverse environments. As a result of
recent advancements in material science, new materials like fiber-reinforced
polymers and multi-functional materials that exhibit high ductility have been
developed and widely used; for example, as infrastructural materials or in
medical devices (e.g., stents). The traditional small-strain approaches of
modeling these materials will not be adequate. In this paper, we study
degradation of materials due to an exposure to chemical species and temperature
under large-strain and large-deformations. In the first part of our research
work, we present a consistent mathematical model with firm thermodynamic
underpinning. We then obtain semi-analytical solutions of several canonical
problems to illustrate the nature of the quasi-static and unsteady behaviors of
degrading hyperelastic solids.
