Failure analysis of composite bolted joints by an experimental and a numerical approach

Benoît Montagne (1) , Frederic Lachaud (1) , Eric Paroissien (1) , Dominique Martini (2)

1 ICA - Institut Clément Ader
2 Dassault Aviation

Composite materials are widely used by aircraft manufacturers because of their high mechanical properties. These properties severely decrease when composite material are drilled and bolted. To avoid structural failure, the behavior of composite bolted joints has to be understood and mastered. An experimental database was constituted by Dassault Aviation with supported single-shear tests with countersunk head screws on different composite materials. This database is analysed to find the main parameters that lead to the failure of the joint. The end distance is the most important parameter. It has a strong influence on both the bearing stress at failure and the failure mode. Width and lay-up have a lower effect on joint failure. A two-dimensional finite element (FEM) model with elastic membrane behavior is then developed to simulate the different configurations in the database. Fiber failure criteria is computed and the dispersion of the results for each failure mode is compared to the dispersion of the experimental data to evaluate the quality of the model. The modification of the failure criteria by taking into account different ply orientations and shear stress permits to reduce the dispersion but it is still higher than the dispersion of the experimental data. This work highlights the limits of such linear 2D modelling and it confirms the needs for more complex modelling such as the local bending effects of the joints and/or the non linear behavior of the composite material.

Mots clés: Composite material; Bolted joint; Finite element analysis

Domaines: Mécanique des matériaux [physics.class-ph]

Benoît Montagne, Frederic Lachaud, Eric Paroissien, Dominique Martini. Failure analysis of composite bolted joints by an experimental and a numerical approach. 18th European Conference on Composite Materials (ECCM18), Jun 2018, Athens, Greece. pp.1-8. ⟨hal-01892096⟩