Damage of Carbon/ Epoxy Composite Plates Subjected to Mechanical Impact and Simulated Lightning Strike

摘要

Lightning Damage is inflicted on carbon fiber/epoxy composite plates usingrnboth simulated lightning strike and mechanical impact in the effort to understand thernrelative effect of the two damage mechanisms. A methodology is proposed torncharacterize the damage resistance and tolerance of unconfigured composite platesrnsubjected to lightning strike in a fashion that is consistent with the extensive workrnpreviously done on low velocity impact. Using current and voltage diagnostics it isrnpossible to extrapolate the amount of electro-mechanical energy absorbed by the platernduring the strike, and compare it to that absorbed during a mechanical impact.rnDamage resistance is characterized by means of ultrasonic C-scans and microscopy,rnwhile residual strength is measured by means of Compression After Impact (CAI)rntesting. Results show that the energy dissipated in a specimen during the lightningrnstrike is much greater than the strain energy introduced by mechanical impact, andrnhence a comparison based on energy is not recommended. However, based on thernrelative threat levels associated with the impact and the lightning strike events, therncomparison yields insightful observations on both damage state and residualrnperformance. In general, for the configurations tested, lightning strike damage seemsrnto be less detrimental than the mechanical impact in terms of both damage area andrnresidual strength.