title: Stress delocalization in crack tolerant electrospun nanofiber networks.
abstract: The fracture toughness of a noncontinuum fibrous network produced by electrospinning polyamide 6 nanofibers is investigated. The mechanical properties of the nanofiber network is observed to be independent of various incorporated macroscopic crack lengths, resulting in an apparent increase in fracture toughness with increasing crack length as evaluated using conventional fracture mechanics. Strain mapping of the nanofiber network indicates stress delocalization mechanisms operating around these macroscopic cracks in the network. The deformation behavior of the nanofiber network will therefore depend on the volume of fibers being loaded in the network and not the number of fibers in the cross-sectional width defining continuum sample mechanics. These results indicate a propensity for both the synthetic electrospun nanofibrous network in this work and potentially other nanofibrous networks to resist failure from macroscopic cracks incorporated within the material.
authors.affiliation: Nanoforce Technology, Ltd., School of Engineering and Materials Science, Queen Mary University of London, Mile End Road, London E1 4NS, United Kingdom.
authors.forename: Urszula
authors.initials: U
authors.lastname: Stachewicz
authors.forename: Ilker
authors.initials: I
authors.lastname: Peker
authors.forename: Wei
authors.initials: W
authors.lastname: Tu
authors.forename: Asa H
authors.initials: AH
authors.lastname: Barber