Inverse identification method of adhesive creep properties from real scale investigations on bonded fastener
Résumé
The use of structural adhesive bonding is under development for offshore applications and more specifically for fastener connection to existing steel structures. For this application, creep appears to be one of the main long-term phenomena that needs to be considered during the design approach. To investigate this issue, experimental creep investigations were realised at real scale for two bonded fastener geometries at different stress levels and under different load situations (tension and shear). Local measurements were carried out during these investigations to better describe the long-term behaviour of the bonded fasteners. Despite the non-uniform adhesive thickness in the assembly, numerical investigations have highlighted that the stress field mainly depends on the fastener geometry and the applied load level. This article is dedicated to the description of a methodology that relies on a precise inverse identification of creep parameters and on simplifying hypotheses on the stress field to be able to use simple analytical tools. The methodology enables to identify creep parameters much quicker than a method coupling an optimisation algorithm and a finite element analysis and could easily be used for more complex and precise models.