New theory explaining Griffith strength results on nano-cracked glass fibres

Author:

Kendall Kevin1

Affiliation:

1. HydrogenUnited.org, 56 Harborne Road, Edgbaston, Birmingham B15 3HE, UK

Abstract

The purpose of this paper is to propose a mechanism and theory that can explain the extraordinary increase in measured strength that Griffith observed for glass fibres containing nano-cracks. His 1921 theory (Griffith 1921Phil. Trans. R. Soc. Lond. A221, 163–198. (doi:10.1098/rsta.1921.0006)) predicted that the strength of a cracked sample should be independent of sample size, yet his results on stretched glass fibres gave strength increasing almost as the inverse of fibre diameter. He proposed a ‘flaw statistics’ argument in an attempt to explain these bizarre results, suggesting strength increased because large defects were less likely in the smaller volumes. But this ‘flaw statistics’ concept is unnecessary because the Griffith energy criterion of cracking must give a size effect, as demonstrated in many different crack-testing configurations. In general, the Griffith energy criterion for crack equilibrium predicts strength rising for smaller samples because such samples contain less volume energy to create new crack surface energy. The problem is that this ‘size effect’ idea has not until now been properly defined for the simple tension crack test. The new idea proposed is that many nano-cracks are likely to exist in an experimental glass sample, so these must also obey the thermodynamic analysis. A problem then arises because, as the main crack propagates, other cracks may close, but healing is not reversible in glass so thermodynamics does not apply completely to these secondary cracks. Crack healing is in the Griffith theory, which is perfectly reversible mathematically, though not explicitly stated.This article is part of the theme issue 'Nanocracks in nature and industry'.

Publisher

The Royal Society

Subject

General Physics and Astronomy,General Engineering,General Mathematics

Cited by 3 articles. 订阅此论文施引文献 订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献

1. Glass fiber/epoxy composites with improved interfacial adhesion by using cross‐linking sizing agent;Polymer Composites;2023-11-07

2. Nano-samples give higher brittle strength by the Griffith energy principle;Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences;2022-08

3. Nanocracks in nature and industry;Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences;2022-08

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3