Enhanced fault-tolerance in biomimetic hierarchical materials -- a simulation study

TL;DR

This simulation study demonstrates that hierarchical microstructures in biomimetic materials significantly improve fault tolerance by arresting crack propagation, thus enhancing resilience and fracture toughness.

Contribution

The paper introduces a large-scale 3D hierarchical beam-element simulation framework capturing multi-scale microstructural effects on fracture behavior.

Findings

Hierarchical microstructures can arrest crack propagation.

Hierarchical systems show reduced sensitivity to pre-existing damage.

Enhanced fault tolerance compared to non-hierarchical fibrous materials.

Abstract

Hierarchical microstructures are often invoked to explain the high resilience and fracture toughness of biological materials such as bone and nacre. Biomimetic material models inspired by those structural arrangements face the obvious challenge of capturing their inherent multi-scale complexity, both in experiments and in simulations. To study the influence of hierarchical microstructural patterns in fracture behavior, we propose a large scale three-dimensional hierarchical beam-element simulation framework, where we generalize the constitutive behavior of Timoshenko beam elasticity and Maximum Distortion Energy Theory failure criteria to the complex case of hierarchical networks of approximately 5 million elements. We perform a statistical study of stress-strain relationships and fracture surface mophologies, and conclude that hierarchical systems are capable of arresting crack propagation, an ability that reduces their sensitivity to pre-existing damage and enhances their fault tolerance compared to reference generic fibrous materials.