Experimental and numerical analysis of unfolding failure of L-shaped CFRP specimens

Pierre Journoud (1, 2) , Christophe Bouvet (1) , Bruno Castanié (1) , Frédéric Laurin (3) , Léon Ratsifandrihana (2)

1 ICA - Institut Clément Ader
2 Segula Technologies [France]
3 DMAS, ONERA, Université Paris Saclay (COmUE) [Châtillon]

Highly curved laminated parts are used at the junction between two different perpendicular panels on aircraft primary structures. Usually, these laminates fail by delamination due to a bending moment, which appears when the part is loaded. The bending moment tries to flatten the part and out-of-plane tensile stresses are generated in the curvature. This failure is traditionally called unfolding failure. The modelling strategy called the 'Discrete Ply Model' (DPM) is used to simulate four-point bending tests on L-angle specimens. Experimental results of four point bending tests carried out at ONERA are used to validate the approach. Four different stacking sequences with the same thickness are taken into consideration in this study. In a second part, a sensitivity analysis on frictional coefficient, intralaminar matrix cracking, transverse tensile and shearing strength, and critical energy release rate in modes I and II is performed numerically and provides an original explanation of the failure scenario and the most influential parameter.

Mots clés: COMPOSITE L-ANGLE; UNFOLDING FAILURE; TRANSLAMINAR MATRIX CRACKING; DELAMINATION

Domaines: Sciences de l'ingénieur [physics]; Physique [physics]; Chimie

Pierre Journoud, Christophe Bouvet, Bruno Castanié, Frédéric Laurin, Léon Ratsifandrihana. Experimental and numerical analysis of unfolding failure of L-shaped CFRP specimens. Composite Structures, 2019, 232, 111563, p. 1-13. ⟨10.1016/j.compstruct.2019.111563⟩. ⟨hal-02382912⟩