The effect of debonding on the natural frequencies of laminated fibre composite sandwich plates

Karunasena, Warna (2010) The effect of debonding on the natural frequencies of laminated fibre composite sandwich plates. In: 6th Australasian Congress on Applied Mechanics (ACAM 6) , 12-15 Dec 2010, Perth, Western Australia.

Abstract

A new generation composite sandwich made up of glass fibre reinforced polymer skins and lightweight but high strength core material has been developed in Australia. A structural composite plate or slab can be manufactured by gluing a number of these sandwiches to satisfy the design requirements. The presence of unbonded areas in the glue line due to manufacturing faults or deterioration in bond in some of the originally fully bonded areas due to aging is a possibility in a FRP structure consisting of glue-laminated fibre composite sandwich plates. The presence of no bonding in some areas of the glue line may cause changes to the vibration parameters, such as natural frequencies and mode shapes, of the plate structure. In particular, unbonded areas could reduce the natural frequency and if the reduced natural frequency is close to the working frequency of the plate structure, resonance could happen. Therefore, it is necessary to make accurate predictions of changes in natural frequencies in such plates. This paper presents a numerical investigation into changes in natural frequency due to various amounts of debonding along the glue line in a laminated fibre composite sandwich plate structure. The need for 3D finite element modelling is avoided by innovatively using the plate and link elements in Strand7 finite element software package to model the plate behaviour by giving due consideration to bonded and unbonded surfaces between plate layers. The accuracy of the numerical solution is verified by comparing present results with bench mark solutions reported in the literature. Variation of the natural vibration frequencies with different debonding areas and locations for a 4 layer sandwich plate structure is presented


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Item Type: Conference or Workshop Item (Commonwealth Reporting Category E) (Paper)
Refereed: Yes
Item Status: Live Archive
Additional Information: Copyright 2010 Engineers Australia. Permanent restricted access to published version due to publisher copyright policy
Depositing User: Assoc Prof Karu Karunasena
Faculty / Department / School: Historic - Faculty of Engineering and Surveying - Department of Agricultural, Civil and Environmental Engineering
Date Deposited: 07 Jan 2011 00:49
Last Modified: 28 Nov 2014 06:42
Uncontrolled Keywords: composite sandwiches; laminated sandwich plates; free vibration; debonding; delamination; natural frequencies
Fields of Research (FOR2008): 09 Engineering > 0905 Civil Engineering > 090506 Structural Engineering
09 Engineering > 0912 Materials Engineering > 091202 Composite and Hybrid Materials
09 Engineering > 0913 Mechanical Engineering > 091304 Dynamics, Vibration and Vibration Control
Socio-Economic Objective (SEO2008): B Economic Development > 87 Construction > 8702 Construction Design > 870201 Civil Construction Design
URI: http://eprints.usq.edu.au/id/eprint/9308

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