Rational design of flexible composites, such as fiber-reinforced rubber goods, demands quantitative descriptions of performance of fibers and fiber assemblies, matrix materials, interfaces and composites, under complex modes of deformation and over a range of broad range of time, temperature and chemical environments. In order to address the underlying issues comprehensively, we have initiated a series of investigations pertaining to
• axial stiffness of fibers and twisted fiber assemblies (yarns and cords)
• mechanical properties of fibers and yarns under complex modes of deformation
• creep response of fibers and twisted fiber assemblies
• morphological responses of fibers and twisted fiber assemblies to chemical/mechanical treatments
An important aspect in this investigation is the exploration of molecular-level modeling of mechanical properties of the reinforcing structures, viz., fibers, yarns and cords. This approach is based on the overall orientation distribution of elementary structural elements in these materials and either the known or fitted properties of the material elements. It also utilizes the pseudo symmetry in these structures. The new approach, if established to have broader validity, would provide a rational mechanism for quantitatively linking the performance characteristics of various fiber assemblies and also for incorporating the chemical/morphological changes which might be caused by the conditions in processing and use of reinforced rubber goods.