100 years after Griffith: From brittle bulk fracture to failure in 2D materials

Abstract

Brittle fracture and ductile failure are critical events for any structural or functional component, as it marks the end of lifetime and potential hazard to human life. As such, materials scientists continuously strive to better understand and subsequently avoid these events in modern materials. A century after the seminal initial contribution by Griffith, fracture mechanics has come a long way and is still experiencing vivid progress. Building on classical fracture testing standards, advanced in situ fracture experiments allow local quantitative probing of fracture processes on different length scales, while microscopic analysis grants access to chemical and structural information along fracture paths in previously unseen detail. This article will provide an overview of how these modern developments enhance our understanding of local fracture processes and highlight future trends toward designing strong yet ductile and damage-tolerant materials. Graphical abstract

Vacancy-mediated inelasticity in two-dimensional vanadium-based dichalcogenides

“…Fracture initiation in these materials commonly occurs in defective regions, such as point vacancies, cracks, dislocations, and grain boundaries. 43,63 For instance, Wang et al 64 conducted in situ TEM experiments to investigate the fracture evolution of CVD in single-layer MoS 2 . It was observed that crack propagation predominantly takes place in the zz direction, and the presence of S atoms plays a crucial role in sustaining a large crack tip.…”

Our first dedicated Impact issue: A snapshot of emerging original research

“…Materials failure is a critical frontier and addresses a number of societal challenges understanding and preventing fracture in metals, alloys, and composites to biological materials. As we celebrate the 100th anniversary of Griffith's seminal article, 6 fracture mechanics is being applied to understand fracture in increasingly complex materials, such as polymers, biomaterials, two-dimensional materials, and hierarchical architected materials, to name a few examples. In "Hydrolysis embrittles poly(lactic acid)," Suo and Vlassak et al 7 report a detailed analysis of a new class of high-molecular weight biodegradable biologically derived polymers that often contain ester and amide bonds that are susceptible to hydrolysis leading to embrittlement.…”