After speaking to our materials test engineers and the technical customer support engineer at Henkel (who produce a range of adhesives used in the aerospace industry) there is no known method to them of converting a peel strength which is peel on a line i.e. 1D to peel over an area i.e. 2D
Can you please offer me some advice on how you would obtain a peel strength over an area? The only way I can think of doing it is to make an assumption of the peel zone. This means it is not over a line but has an assumed length. This may lead to inaccuracies and large variation.
AID160-180 claims that the Fpeel (bondline peel strength), which I assume is the allowable which is inputted in the material database in MPa or psi, can be obtained from a tensile shear specimen. How? The tensile shear test methods, like ASTM D 1002, 2919, 3163 & 3165, only generate shear strength. Even though I do appreciate that the tensile lap shear test specimen does generate both shear and peel stresses at failure, it is only the shear strength that can be readily measured, even if it is not the most accurate when using thin adherends. For lap shear tests with thick stiff adherends the peel is reduced and the shear strength more accurate.
This is a problem which does not allow us to fully utilise the bonded joint analysis.