The prize was awarded for the paper titled “Influence of nonlinearities on the accuracy of the analytical solution for the shaft loaded blister test” which was published in the renowned “International Journal of Solids and Structures” in January 2011 (Vol. 48, Page 1424–1435). The paper co-authored by Meng Hou (UQ), Martin Veidt (UQ) and Paul Falzon (ACS Australia) employed finite element analysis (FEA) to study the effects of nonlinearities on the accuracy of the analytical solution for the shaft loaded blister test.

The blister test can be used for the assessment of thin plastic coatings on composite or other substrates. Non-catastrophic crack propagation and a distinct fracture mode which favours crack propagation in the film/substrate interface are the main advantages of the blister test. In its study on efficient helicopter component manufacture, CRC-ACS addressed the use of in-mould primer and required a rapid means for assessing the quality of its attachment. The work on blister testing potentially has future relevance to the assessment of attachment quality of thermoplastic film to a carbon epoxy substrate for the CRC-ACS Thermoset Composite Welding (TCW) technology.

The FEA model was validated using constrained blister test measurements showing a good correlation between the experimental and the FEA data. The analytical solution was then compared with the energy release rate obtained from J-integral evaluation in the FEA. For small and large shaft displacements deviations larger than 20% are encountered which is explained with the violation of the membrane limit condition and the onset of plasticity for larger displacements, respectively. Simplifications of the analytical solution are discussed using a random sampling method and it is shown that the thickness ratio between film and substrate can be neglected for thin films on rigid substrates. Further, values for the angular quantity, which is required to calculate the mode mix phase angle, are tabulated for the case of thin, elastic films on stiff substrates using a crack surface opening displacement extrapolation method.

Award is handed over by the former Director of the CSIRO Energy Transformed Flagship Program, Dr John Wright (left)