Measurements of Interface Fracture Strength between Fiber-Reinforced Composite Laminates and Thin Surface Films Using the Blister Test

The blister test is a promising test method to determine the interface fracture toughness of thin films adhering to rigid fibre reinforced plastics. In this paper nonlinear finite element analysis is used to determine a suitable layout for both the shaft loaded and the pressurised blister test. On the example of a PET film adhering to a quasi-isotropic fibre reinforced plastic, it is shown that energy release rates in a range of 0-1500N/m can be obtained for a 0.5mm thick film if test parameters are carefully selected. The two main causes for deviations of the analytic solution from the FEA results is attributed to infringement of the membrane limit condition and plastic deformation in the film.