Toughening mechanisms and damage propagation in Architected-Interfaces

TL;DR

This paper explores the fracture toughness of architected interfaces with complex geometries, developing models to predict failure loads and damage propagation, and demonstrating how certain designs enhance structural stability and fail-safe behavior.

Contribution

It introduces theoretical and numerical frameworks for evaluating fracture properties of architected interfaces with novel geometries, highlighting mechanisms that improve damage tolerance.

Findings

Models accurately predict compliance and failure loads.

Certain geometries unfold during fracture, increasing failure load.

Designs enable stable, controlled damage propagation.

Abstract

We investigate fracture toughness of architected interfaces and their ability to maintain structural integrity and provide stable damage propagation conditions beyond the failure load. We propose theoretical and numerical frameworks to evaluate the fracture properties of architected interfaces sandwiched between two (face) materials. The microscopic geometries of these interfaces are chosen as 2D cells--pillar, tetrahedron, and hexagon--as well as their 3D counterparts--namely, pillar array, octet truss, and Kelvin cell. Our model, both numerical and analytical, exhibits a high level of accuracy in predicting the compliance before failure and failure loads. Novel results are obtained during the damage propagation regime, indicating fulfilment of the so-called fail-safe design. Some of the cell geometries unfold during fracture, thus increasing the failure load and ensuring stable and controlled damage propagation conditions.