Failure and fracture processes underlie a broad range of pathologies involving soft tissues. Material models that predict these processes are in general difficult to compose and validate. My group focuses on the modeling of failure and fracture by treating failure as the onset of material instability, and by treating fracture as the localization and propagation of damage.
The talk will begin with material models that show promise for predicting the failure of aneurysms: weak, distended soft tissue in artery walls whose rupture is often fatal. Failure models are needed for surgical decisions and planning. The approach that we take is to use bounds on stress and strain energy density as indicators of material failure. As the talk will describe, the rationale for this is that because the number of macromolecules in a representative volume of a material is bounded, the total bond energy and hence macroscopic strain energy density must be bounded as well. This requires limits on the stress that a material can sustain. The talk will present implications of the introduction of the bounded strain energy with regard to analysis of material instability in the soft tissues of the vasculature.
In soft tissues and in continuum mechanics in general, modeling of how the onset of failure progresses into fracture and crack propagation requires a regularized approach. Most existing approaches utilize purely mathematical regularization schemes that lack physical grounds. We offer a more physically based approach rooted in the idea that bulk cracks are not a peaceful unzipping of adjacent atomic/molecular layers but rather a catastrophic explosion of bonds localized within a finite characteristic length. We consider implications of this standpoint concerning analysis of the dynamic crack propagation in soft matter.
Konstantin (Kosta) Volokh is an expert in the mechanics of soft materials and biological tissues serving on the faculty of the Technion (Israel Institute of Technology). His specific expertise lies in the modeling of failure and fracture of these material systems. Prof. Volokh is Editor-in-Chief of the journal, “Molecular and Cellular Biomechanics,” and is founding Editor-in-Chief of the new Springer journal, “Mechanics of Soft Materials.” He is author of the Springer monograph, Mechanics of Soft Materials, now in its second edition, and of over 100 refereed articles. Prof. Volokh earned a Ph.D. from Moscow State University in 1991, and has served at the Technion continuously since beginning as a post-doc in 1994.
Host: Prof. Guy Genin
Faculty, students, and the general public are invited.
Hosted by: Prof. Guy Genin