Equivalent impact set-up for lightning strike damage on composite coupons
Résumé
Lightning strikes of composite materials induce two distinct kinds of direct effects: surface and bulk mechanical damage. Bulk damage includes fiber-resin debonding, transverse cracks, fiber rupture and ply delamination. It results from the mechanical stresses associated to physical processes which come with lightning strikes such as surface explosion or magnetic force generation. We propose a method to design mechanical impact tests representative of lightning tests in the sense that strains and stresses applied to the material in both experimental situations are comparable. A campaign of actual equivalent mechanical test and has been designed using a simulation driven procedure and performed in the maboratory. The procedure of the method of equivalence is demonstrated trough the comparison of numerical and real impact tests observations with lightning strikes measurements of rear face displacements and internal damaged areas.