Behaviour of laminated fibre composite sandwich girders

Pickford, Christopher Ian (2009) Behaviour of laminated fibre composite sandwich girders. [USQ Project] (Unpublished)

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Abstract

The objective of this work was to determine experimentally the flexural behaviour of laminated composite sandwich beams based on orientation and the number of laminations. The failure modes and loads were numerically modelled and predicted analytically. The sandwich beams were fabricated using a new generation of sandwich composite with biaxial glass fibre/resin skin and an innovative phenolic based core material. The laminated beams were subjected to 4-point static bending tests to determine the strength and failure mechanisms. The beams tested consist of one to four laminates in the flatwise and edgewise orientation. Strains to failure in the face sheets were measured through the use strain gauges and beam deflections were recorded for each specimen. The results of the experimental investigation demonstrated that the laminated sections tested in the edgewise orientation failed at a higher load than those in the flatwise orientation. The flatwise specimens had a brittle type failure. This was primarily due to the compressive failure of the skin followed by debonding between the skin and the core. The vertical skins in the edgewise orientation caused a difference in the failure mode and ultimately facilitated the increase in ultimate strength. The vertical skins prevented the tension cracks in the core from propagating and caused ductile type failure mode through the progressive failure of the skins. The analytical predictions from the constituent material data confirmed the experimental results. The analytical investigation conducted predicted the load deflection behaviour and initial failure loads. The results from the linear numerical modelling are in agreement with those observed in the experimental data. The experimental data established that for a higher number of laminations the beam sections in the edgewise orientation provides an optimal alternative to the flatwise orientation. It was found that the edgewise orientation provides a higher ultimate strength, ductile type failure and comparable stiffness to the flatwise orientation. The results indicated a high potential for the use of laminated sandwich beams as structural elements in both the flatwise and edgewise orientations


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Item Type: USQ Project
Refereed: No
Item Status: Live Archive
Depositing User: epEditor USQ
Faculty / Department / School: Historic - Faculty of Engineering and Surveying - Department of Agricultural, Civil and Environmental Engineering
Date Deposited: 26 Jul 2010 02:00
Last Modified: 29 Jul 2010 00:17
Uncontrolled Keywords: fibre composites; sandwich beams; laminated sections; testing
Fields of Research (FOR2008): 09 Engineering > 0905 Civil Engineering > 090503 Construction Materials
09 Engineering > 0912 Materials Engineering > 091202 Composite and Hybrid Materials
URI: http://eprints.usq.edu.au/id/eprint/8519

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