Numerical approach for assessment of dynamic strength for riveted joints

Numerous rivets have to be modelled for aeronautical framework crashes. A numerical procedure based on FE modelling and characterisation of material failure constitutive models is proposed in order to limit the experimental procedure. Quasi-static and dynamic experiments are carried out on elementary tension (punched) and shear (riveted) specimens. No strain rate sensitivity has been measured on the riveted joint assemblies failure. The experiments are used to identify, by an inverse method, the Gurson damage parameters of each material (2024-T351 and 7050 aluminium alloys for the sheet metal plate and the rivet). The characterisation gives rise to a satisfactory correlation between FE models and experiments. Optimised parameters are validated for each material by means of a uniaxial tension test for the sheet metal plate and an ARCAN type specimen in pure tension for the rivet. Results can then be used to identify macroscopic failure criterion to model the rivet behaviour in aeronautical framework crashes. FE tools can also resolve problems linked to limit-design or the design of new riveted joint assemblies more rapidly and cost effectively than experiments. (C) 1999 Editions scientifiques et medicales Elsevier SAS.