A predictive micromechanically-based model for damage and permanent deformations in copolymer sutures

A predictive microstructure-based approach for the anisotropic damage, residual stretches and hysteresis in biodegradable sutures

“…In this section we extend a model for biodegradable sutures proposed by some authors of this paper [1] in several directions. On one side we consider the important anisotropic effect in the evolution of the natural molecules configurations and the topological network constrains, on the other side, by introducing recrosslinking effect, we describe the important experimental effect of internal hys-teresis cycles.…”

“…Following the approach in [1], we base our model on Flory's assumption that the expected end-to-end length Ln of the co-polymer macromolecules composed of n Kuhn segments of length b can be estimated, based on classical statistical mechanics (see [23]), as…”

“…In this paper, we extend our previous approach proposed in [1] by accounting for a fully three-dimensional point-wise distribution of polymeric chains whose properties vary with stretch history. As well known, soft materials are characterized by a fundamental anisotropy of damage since each chain natural configuration depends on its own extension history.…”

Spider silks mechanics: predicting humidity and temperature effects

“…This energy respects the limit extensibility condition, lim L→Lc ϕ e (L, L c ) = +∞, and allows for explicit calculations. Moreover, following [27], we extend this function to consider that, as described above, the end-to-end length L can be decomposed in the permanent part measured by ( 1) and an elastic part L e = L − L n . Thus we assume ϕ e = κ L 2 e Lc−L and a force-elongation law…”

“…We have λ h c = nh (λ max )/ n h o and λ h n = nh (λ h max )/n h o , respectively. Since the effective stretch-induced unfolding depends on the unknown size and strength crystals distribution, following [27] we assume a simple power law…”