Title: Lightning Strike Testing on Integrally Stiffened Stringer Panels

Authors: J. Andrew Baker and Brian Kitt

DOI: 10.33599/nasampe/c.19.0783

Abstract: Recent designs for commercial transport fuselages have incorporated skin-stringer configurations manufactured from composite carbon/epoxy unidirectional tape materials. Depending on the specific aircraft, the stringer geometry varies based on optimizing the configuration for a given set of design objectives. One design requirement that affects composite fuselage structure more than previous metallic designs is the consideration of lightning strike effects and the resulting damage to the aircraft structure.

A number of metallic meshes, foils and wire configurations are commercially available for lightning strike protection of composite aircraft structure. These materials can be embedded as part of the outer layer during the cure process or subsequently bonded to the already cured composite skin. These protection schemes are generally evaluated with a simulated lightning strike event and the resulting damage, if any, is then assessed.

To assist in optimizing a fuselage skin-stringer design, lightning strike susceptibility was evaluated for several configurations of the stringer component. The unique shapes and construction details were evaluated comparatively and were judged against a known acceptable configuration. Additionally, two specific types of protection schemes were applied to the skins and were evaluated for each of the stringer configurations. Since lightning strike damage is dependent on the intensity and duration of the lightning event, two different waveforms were used. One was to represent an extreme event (Zone 2A) whereas the other was to represent a more typical event (Zone 3). Damage to the panels was evaluated using non-destructive inspection (NDI) techniques and then the panels were subsequently dissected and photomicrographs were obtained.

References: 1. ARP5412 Rev. B. “Aircraft Lighting Environment and Related test Waveforms.” SAE International, Jan. 2013 2. ARP5414 Rev. B. “Aircraft Lighting Zone.” SAE International, Dec. 2018 3. ARP5416 Rev. A. “Aircraft Lighting Test Methods.” SEA International, Jan. 2013. 4. J. Welch, B. Kitt, R. Meusborn, ”Lightning Strike Testing Results on Honeycomb Panels Protected with a Series of Metal Mesh Products”, Proceedings of the International SAMPE Symposium and Exhibition , Baltimore, Maryland, June 2007 5. 18-2152-TR201 Rev.-. Owens, Reid. “Strategic Projects Composite Panel Lighting Strike Test Report.” National Institute for Aviation Research, 12 July 2018

Conference: CAMX 2019

Publication Date: 2019/09/23

SKU: TP19-0783

Pages: 14

Price: $28.00