The effect of local copper mesh geometry on the damage induced in composite structures subjected to artificial lightning strike

Artificial Current Component A lightning strike tests were performed on three different types of composite panels. Panels of type A were not equipped with lightning strike protection; panels of types B and C were protected against lightning strike with two different types of copper mesh. The measured back surface velocity of the panels seems to be proportional to the peak current normalized with the panel weight. Post-test inspections revealed extended delamination inside panels of type A. For panels of types B and C no delamination was found. Panels of type B and C showed characteristic circular smuts on the impacted surface as well as diamond shaped evaporation of the copper mesh. For panels of type B, the dimensions of the copper evaporation were significantly larger than for panels of type C. it was also found that the orientation of the evaporation zone seems to be related to the geometry of the copper mesh. Multi-physical simulations considering the electro-explosion of the copper mesh were carried out in order to assess if the shape and extent of the evaporation zone could be traced back to electro-explosion of the copper mesh. The predicted damage correlates well with the inner damage zone, but is not able to reproduce the full amount of copper evaporation.