סמינר מחלקה של דריה אורלובה - הומוגניזציה לא ליניארית של רשתות אלסטיות אקראיות עם יישום על חומרים ביולוגיים סיביים

School of Mechanical Engineering Seminar
Monday December 11.12.2023 at 14:00

ZOOM SEMINAR

Nonlinear Homogenization of Random Elastic Networks with Application to Fibrous Biomaterials

Daria Orlova

PhD student under the supervision of Dr. Igor Berinskii

MultiScale Mechanics of Solids Group

School of Mechanical Engineering, Tel Aviv University, Israel

This study investigates the mechanical properties of random elastic networks inspired by the extracellular matrix (ECM). The ECM is a three-dimensional fibrous microenvironment that supports biological cells and facilitates their interactions. The mechanical characteristics of this supporting network significantly impact cellular behavior. Additionally, mechanical interactions between cells and their environment lead to substantial displacements, fiber reorientation, and, consequently, local anisotropy. The non-homogeneous and entangled microstructure of the matrix, composed of fibers that are randomly oriented and distributed in varying sizes, complicates its description using classical continuum models. Meanwhile, discrete models, which approximate the real microstructure in simulations, require substantial computational resources.

To address these complexities, we introduce a homogenization method for determining the effective properties and analyzing structural changes in the bio-inspired material. This method specifically examines how external stretching modifies material anisotropy. Incorporating both 2D and 3D models, along with experimental data, we employed both static and dynamic formulations. Our focus is on analyzing the effective elastic properties of networks with varying densities and compositions, based on a predefined random microstructure. Our numerical strategy employs boundary periodicity, and uniaxial and biaxial loading in a representative volume element (RVE) containing numerous randomly distributed elements to determine these properties. Systematic evaluations produced stress-stretch curves that correlate with hyperelastic models for networks at different connectivity levels.

These findings offer deeper insights into the mechanics of bio-inspired materials, emphasizing cellular interactions within matrices. Our computational approach to this micromechanics problem enables the prediction of multi-axial properties, which are typically challenging to determine experimentally. By employing homogenization, we not only reduce the computational demands for simulations but also simplify the modeling of complex fibrous structures. This facilitates the replication of diverse fibrous material behaviors in straightforward finite element models. Such simplification is crucial for effectively addressing mechanobiological issues at both the cellular and larger scale levels.

Our homogenization methodology extends beyond the specific bio-inspired material to a wide variety of similar materials and fabrics. This adaptability enables the investigation of a diverse class of materials, especially viscoelastic ones, by integrating their inherent viscous behavior into the matrix analysis.

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https://tau-ac-il.zoom.us/j/86497933118