A model of connective tissue micromechanics

Unifying concepts at the level of microstructure are developed to account for macroscopic connective tissue elasticity, energy dissipation, and its time-varying response to mechanical loads. A fiber-fiber kinetics model based on the assumption that both rate-dependent and rate-independent dissipative stresses arise in the interaction among fibers in the connective tissue matrix is established. The model accounts for the principal features observed in the tissue behavior. These include the amplitude dependence, the frequency dependence, time-amplitude and frequency-amplitude interactions, and preconditioning phenomena. The model offers a physical explanation of microstructural behavior in terms of slip and diffusion layers. The model implies that the relaxation spectrum is not simply a mechanical property of the material; it depends on loading amplitude. The model is conceptually simple. It contains only two powerful and unifying ideas-the slip and the diffusion layers