Puncturing of soft tissues: experimental and fracture mechanics-based study.

The integrity of soft materials against puncturing is of great relevance for their performance because of the high sensitivity to local rupture caused by rigid sharp objects. In this work, the mechanics of puncturing is studied with respect to a sharp-tipped rigid needle with a circular cross section, penetrating a soft target solid. The failure mode associated with puncturing is identified as a mode-I crack propagation, which is analytically described by a two-dimensional model of the target solid, taking place in a plane normal to the penetration axis.

Additively Manufactured Multi-Morphology Bone-like Porous Scaffolds: Experiments and Micro-Computed Tomography-Based Finite Element Modeling Approaches.

Tissue engineering, whose aim is to repair or replace damaged tissues by combining the principle of biomaterials and cell transplantation, is one of the most important and interdisciplinary fields of regenerative medicine. Despite remarkable progress, there are still some limitations in the tissue engineering field, among which designing and manufacturing suitable scaffolds. With the advent of additive manufacturing (AM), a breakthrough happened in the production of complex geometries.

Statistical Damage Mechanics of Polymer Networks.

The macroscopic mechanical response of polymers can be traced down to the microscale physics of the network by using a statistical approach for the description of the configuration state of the polymer chains. In this paper we present a micromechanical model to capture the macroscopic behavior of polymers by tracking the evolution of a distribution function describing chain configurations, more specifically the statistics of the end-to-end distance on the network chains. Damage, manifested in the softening and hysteresis under cyclic loading, is accounted for through the scission of chains, whose occurrence is evaluated on the basis of the probability of failure, also settled in the configuration space.

Viscous and Failure Mechanisms in Polymer Networks: A Theoretical Micromechanical Approach.

Polymeric materials typically present a complex response to mechanical actions; in fact, their behavior is often characterized by viscous time-dependent phenomena due to the network rearrangement and damage induced by chains' bond scission, chains sliding, chains uncoiling, etc. A simple yet reliable model-possibly formulated on the basis of few physically-based parameters-accounting for the main micro-scale micromechanisms taking place in such a class of materials is required to properly describe their response. In the present paper, we propose a theoretical micromechanical approach rooted in the network's chains statistics which allows us to account for the time-dependent response and for the chains failure of polymer networks through a micromechanics formulation.

A simple statistical approach to model the time-dependent response of polymers with reversible cross-links.

A new class of polymers characterized by dynamic cross-links is analyzed from a mechanical point of view. A thermodynamically consistent model is developed within the Lagrangian framework for polymers that can rearrange their internal cross-links. Such a class of polymers has the capability to reset their internal microstructure and the microscopic remodeling mechanism leads to a behavior similar to that of an elastic fluid.