Influence of the Testing Gage Length on the Strength, Young's Modulus and Weibull Modulus of Carbon Fibres and Glass Fibres

Carbon fibres and glass fibres are reinforcements for advanced composites and the fiber strength is the most influential factor on the strength of the composites. They are essentially brittle and fail with very little reduction in cross section. Composites made with these fibres are characterized by...

Full description

Bibliographic Details
Main Authors: Luiz Claudio Pardini, Luis Guilherme Borzani Manhani
Format: Article
Language:English
Published: Associação Brasileira de Metalurgia e Materiais (ABM); Associação Brasileira de Cerâmica (ABC); Associação Brasileira de Polímeros (ABPol) 2002-10-01
Series:Materials Research
Subjects:
Online Access:http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392002000400004
_version_ 1819089587307282432
author Luiz Claudio Pardini
Luis Guilherme Borzani Manhani
author_facet Luiz Claudio Pardini
Luis Guilherme Borzani Manhani
author_sort Luiz Claudio Pardini
collection DOAJ
description Carbon fibres and glass fibres are reinforcements for advanced composites and the fiber strength is the most influential factor on the strength of the composites. They are essentially brittle and fail with very little reduction in cross section. Composites made with these fibres are characterized by a high strength/density ratio and their properties are intrisically related to their microstructure, i.e., amount and orientation of the fibres, surface treatment, among other factors. Processing parameters have an important role in the fibre mechanical behaviour (strength and modulus). Cracks, voids and impurities in the case of glass fibres and fibrillar misalignments in the case of carbon fibres are created during processing. Such inhomogeneities give rise to an appreciable scatter in properties. The most used statistical tool that deals with this characteristic variability in properties is the Weibull distribution. The present work investigates the influence of the testing gage length on the strength, Young's modulus and Weibull modulus of carbon fibres and glass fibres. The Young's modulus is calculated by two methods: (i) ASTM D 3379M, and (ii) interaction between testing equipment/specimen The first method resulted in a Young modulus of 183 GPa for carbon fibre, and 76 GPa for glass fibre. The second method gave a Young modulus of 250 GPa for carbon fibre and 50 GPa for glass fibre. These differences revelead differences on how the interaction specimen/testing machine can interfere in the Young modulus calculations. Weibull modulus can be a tool to evaluate the fibre's homogeneity in terms of properties and it is a good quality control parameter during processing. In the range of specimen gage length tested the Weibull modulus for carbon fibre is ~ 3.30 and for glass fibres is ~ 5.65, which indicates that for the batch of fibres tested, the glass fibre is more uniform in properties.
first_indexed 2024-12-21T22:10:18Z
format Article
id doaj.art-1e00a64414b34013b42e982777bccaf7
institution Directory Open Access Journal
issn 1516-1439
language English
last_indexed 2024-12-21T22:10:18Z
publishDate 2002-10-01
publisher Associação Brasileira de Metalurgia e Materiais (ABM); Associação Brasileira de Cerâmica (ABC); Associação Brasileira de Polímeros (ABPol)
record_format Article
series Materials Research
spelling doaj.art-1e00a64414b34013b42e982777bccaf72022-12-21T18:48:36ZengAssociação Brasileira de Metalurgia e Materiais (ABM); Associação Brasileira de Cerâmica (ABC); Associação Brasileira de Polímeros (ABPol)Materials Research1516-14392002-10-015441142010.1590/S1516-14392002000400004Influence of the Testing Gage Length on the Strength, Young's Modulus and Weibull Modulus of Carbon Fibres and Glass FibresLuiz Claudio PardiniLuis Guilherme Borzani ManhaniCarbon fibres and glass fibres are reinforcements for advanced composites and the fiber strength is the most influential factor on the strength of the composites. They are essentially brittle and fail with very little reduction in cross section. Composites made with these fibres are characterized by a high strength/density ratio and their properties are intrisically related to their microstructure, i.e., amount and orientation of the fibres, surface treatment, among other factors. Processing parameters have an important role in the fibre mechanical behaviour (strength and modulus). Cracks, voids and impurities in the case of glass fibres and fibrillar misalignments in the case of carbon fibres are created during processing. Such inhomogeneities give rise to an appreciable scatter in properties. The most used statistical tool that deals with this characteristic variability in properties is the Weibull distribution. The present work investigates the influence of the testing gage length on the strength, Young's modulus and Weibull modulus of carbon fibres and glass fibres. The Young's modulus is calculated by two methods: (i) ASTM D 3379M, and (ii) interaction between testing equipment/specimen The first method resulted in a Young modulus of 183 GPa for carbon fibre, and 76 GPa for glass fibre. The second method gave a Young modulus of 250 GPa for carbon fibre and 50 GPa for glass fibre. These differences revelead differences on how the interaction specimen/testing machine can interfere in the Young modulus calculations. Weibull modulus can be a tool to evaluate the fibre's homogeneity in terms of properties and it is a good quality control parameter during processing. In the range of specimen gage length tested the Weibull modulus for carbon fibre is ~ 3.30 and for glass fibres is ~ 5.65, which indicates that for the batch of fibres tested, the glass fibre is more uniform in properties.http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392002000400004carbon fibresglass fibresYoung modulusWeibull modulus
spellingShingle Luiz Claudio Pardini
Luis Guilherme Borzani Manhani
Influence of the Testing Gage Length on the Strength, Young's Modulus and Weibull Modulus of Carbon Fibres and Glass Fibres
Materials Research
carbon fibres
glass fibres
Young modulus
Weibull modulus
title Influence of the Testing Gage Length on the Strength, Young's Modulus and Weibull Modulus of Carbon Fibres and Glass Fibres
title_full Influence of the Testing Gage Length on the Strength, Young's Modulus and Weibull Modulus of Carbon Fibres and Glass Fibres
title_fullStr Influence of the Testing Gage Length on the Strength, Young's Modulus and Weibull Modulus of Carbon Fibres and Glass Fibres
title_full_unstemmed Influence of the Testing Gage Length on the Strength, Young's Modulus and Weibull Modulus of Carbon Fibres and Glass Fibres
title_short Influence of the Testing Gage Length on the Strength, Young's Modulus and Weibull Modulus of Carbon Fibres and Glass Fibres
title_sort influence of the testing gage length on the strength young s modulus and weibull modulus of carbon fibres and glass fibres
topic carbon fibres
glass fibres
Young modulus
Weibull modulus
url http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392002000400004
work_keys_str_mv AT luizclaudiopardini influenceofthetestinggagelengthonthestrengthyoungsmodulusandweibullmodulusofcarbonfibresandglassfibres
AT luisguilhermeborzanimanhani influenceofthetestinggagelengthonthestrengthyoungsmodulusandweibullmodulusofcarbonfibresandglassfibres