The University of Southampton
University of Southampton Institutional Repository

Stresses around fasteners in composite aircraft structures and effects on fatigue life

Stresses around fasteners in composite aircraft structures and effects on fatigue life
Stresses around fasteners in composite aircraft structures and effects on fatigue life

There is considerable interest in the use of composite materials in aerospace structures. One of the problems encountered in aircraft is that of fasteners and the stress distributions around fasteners in composite structural components are therefore of significance, particularly in relation to fatigue life in the region of stress concentration.

This thesis concerns a programme of research on stresses around fasteners in multilayered Carbon Fibre Reinforced Plastic (CFRP) material; both theoretical work and experimental studies have been carried out.

A commercially available finite element software, ANSYS, has been used to carry out three dimensional stress analyses of CFRP material specimens with holes, loaded in flexure in a cantilever-type of arrangement, the specimen being attached to a rigid support via bolts through the holes. The types of specimens studied were those used in experiments on a robust fatigue rig which was built for the project. The theoretical models showed regions of high direct and shear stresses in the specimens when bent over and away from the clamping support. The practical fatigue tests showed, via ultrasonic scanning and electron microscopy, after a large number of flexural loading cycles where damage initiated in the test specimens and the type of damage induced. A critical part of the work was to compare theoretically predicted regions of high stresses and induced damage in order to establish, if possible, damage inducing mechanisms and the levels, types and combinations of internal stresses which would cause damage to occur.

Correlations have been made between the analytical and practical test results and a relationshp has been demonstrated between high values of direct stress throughout the specimen thickness and delamination. Cracks were associated with high values of shear stress in the plane of reinforcement of the specimens.

Comparisons have been made for CFRP with three different stacking sequences in order to determine the most fatigue resistant of commonly used types of lay-ups.(DX184257)

University of Southampton
Benchekchou, Boutaina
92effdf6-63b4-4be9-9b20-f801b78c3566
Benchekchou, Boutaina
92effdf6-63b4-4be9-9b20-f801b78c3566

Benchekchou, Boutaina (1994) Stresses around fasteners in composite aircraft structures and effects on fatigue life. University of Southampton, Doctoral Thesis.

Record type: Thesis (Doctoral)

Abstract

There is considerable interest in the use of composite materials in aerospace structures. One of the problems encountered in aircraft is that of fasteners and the stress distributions around fasteners in composite structural components are therefore of significance, particularly in relation to fatigue life in the region of stress concentration.

This thesis concerns a programme of research on stresses around fasteners in multilayered Carbon Fibre Reinforced Plastic (CFRP) material; both theoretical work and experimental studies have been carried out.

A commercially available finite element software, ANSYS, has been used to carry out three dimensional stress analyses of CFRP material specimens with holes, loaded in flexure in a cantilever-type of arrangement, the specimen being attached to a rigid support via bolts through the holes. The types of specimens studied were those used in experiments on a robust fatigue rig which was built for the project. The theoretical models showed regions of high direct and shear stresses in the specimens when bent over and away from the clamping support. The practical fatigue tests showed, via ultrasonic scanning and electron microscopy, after a large number of flexural loading cycles where damage initiated in the test specimens and the type of damage induced. A critical part of the work was to compare theoretically predicted regions of high stresses and induced damage in order to establish, if possible, damage inducing mechanisms and the levels, types and combinations of internal stresses which would cause damage to occur.

Correlations have been made between the analytical and practical test results and a relationshp has been demonstrated between high values of direct stress throughout the specimen thickness and delamination. Cracks were associated with high values of shear stress in the plane of reinforcement of the specimens.

Comparisons have been made for CFRP with three different stacking sequences in order to determine the most fatigue resistant of commonly used types of lay-ups.(DX184257)

Text
54777.pdf - Version of Record
Available under License University of Southampton Thesis Licence.
Download (215MB)

More information

Published date: 1994

Identifiers

Local EPrints ID: 458501
URI: http://eprints.soton.ac.uk/id/eprint/458501
PURE UUID: 8357bda8-55b1-4a05-8c6e-9c804fb1fc7d

Catalogue record

Date deposited: 04 Jul 2022 16:50
Last modified: 16 Mar 2024 18:23

Export record

Contributors

Author: Boutaina Benchekchou

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×