Investigation into the delamination of composite laminates on aircraft rudders due to fluid ingress and icing

Pike, Samuel (2015) Investigation into the delamination of composite laminates on aircraft rudders due to fluid ingress and icing. [USQ Project]

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Abstract

Water ingestion into composite structures is one of the many causes of environmental delaminations in the wings of modern composite aircraft. Water ingestion into the composite structure occurs through three distinct pathways; capillary action through cracks in the skin, around fasteners (rivets, bonded joints) and secondary delaminations from previous repairs.

The objective of this research that is being pursued in this research dissertation is to:

To investigate fluid ingress into composite aircraft laminate structure, which can lead to the delamination of the primary structure due to icing. To investigate the best methods of crack propagation accumulation progression and detection via fatigue testing by the use of tensile and flexure methods on fibre composite laminates. To compare the established tensile strength of the fibre composite laminates with results from testing and detect how much earlier the samples start crack propagation.

The results of this dissertation are as follows: under tensile testing: optical, thermography and embedded Fibre Bragg Grating (FBG) sensors were the best methods for detecting crack propagation through composite fibre laminates and under flexure testing strain gauges proved to be the best method of detecting crack propagation in composite fibre laminates.

Under tensile loading of 5Hz, the First and Second tensile samples started crack propagation between 80-93% of the ultimate tensile strength of the fibre laminate as determined by material property testing in Chapter 12.0 of 37.5KN. Under flexure testing of 1Hz the flexure sample started crack propagation at 64% of the of the ultimate tensile strength of the fibre laminate as determined by material property testing in Chapter 12.2 of 3.148KN.

As discussed in section 15.1, thermography and thermostress analysis proved to be the most viable, accurate and most importantly, easiest form of crack propagation detection medium out of the three methods of tensile, flexure and thermography testing used in this dissertation.


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Item Type: USQ Project
Item Status: Live Archive
Additional Information: Bachelor of Engineering (Mechanical) project
Faculty / Department / School: Current - Faculty of Health, Engineering and Sciences - School of Mechanical and Electrical Engineering
Supervisors: Epaarachchi, Jayantha
Date Deposited: 07 Jun 2016 02:05
Last Modified: 07 Jun 2016 02:05
Uncontrolled Keywords: fibre composite laminates, delamination, aircraft rudders, fluid ingress and icing, crack propagation, tensile, flexure, thermography
Fields of Research : 09 Engineering > 0913 Mechanical Engineering > 091399 Mechanical Engineering not elsewhere classified
URI: http://eprints.usq.edu.au/id/eprint/29278

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