Évaluation de la résistance statique d'un joint riveté par la méthode des éléments finis

Abstract

At Bombardier Aerospace, preliminary joint allowable loads allow the selection of fasteners and joints preliminary sizing of the aircraft. This phase, called preliminary design, lasts about six months. Detailed design follows the preliminary design and requires final joint allowable loads to approve the drawings used in the manufacture of the aircraft. This phase lasts about a year. Joint allowable loads are evaluated through tensile tests. Each test provides the static strength of the joint. To date, no analytical method is available to predict joint allowable loads which require a campaign of experimental tests. This study examines the development of a methodology for evaluating the static strength of a riveted joint. In this research, a solid rivet, called Aerolock, made in aluminum 2117-T4 is used to join two sheets of aluminum 2024-T3. The finite element method (FEM) is used to predict the static strength of this riveted joint using ANSYS Workbench. To do this, the installation of the rivet and the tensile test are modeled and solved implicitly. A rigorous characterization of materials allows to accurately evaluating the static strength of the riveted joint. The failure is obtained using a pre-defined area of cohesion in the shear plane of the rivet shank. The analysis of the failure obtained experimentally using a riveted joint of 2.03 mm thick is used to validate the prediction of the finite element model. The finite element model allows obtaining an excellent prediction of the static strength of the riveted joint of 2.03 mm thickness determined experimentally. The model agrees with experimental results with an error of 0.19% for the yield strength and an error of 0.38% for the ultimate strength. This correlation validates partially the numerical model. The computation time is even more satisfactory since the static strength is obtained in only 20 minutes with the modeling strategies employed. The model is then used to predict the joint allowable loads obtained experimentally. To do this, the static joint strength is evaluated for sheet thicknesses of 1.27 mm, 1.60 mm, 1.80 mm and 2.03 mm. The model agrees with allowable loads obtained experimentally with an average error of 1.41% for the allowable elastic loads and an average error of 1.84% for the allowable ultimate loads. These results show that it is possible to use FEM to predict the static strength of a riveted joint.

Date	27 Sept 2012
Original language	French
Awarding Institution	École de technologie supérieure
Supervisor	Anh Dung Ngô (Supervisor) & Pascal Lortie (Co-supervisor)