Abstract:Aircraft grounding grid is responsible for some important functions,such as providing current return path, protecting aircraft from lightning, and electromagnetic disturbance.Its good performance is an important factor affecting the safe and stable operation of aircraft. Compared to the metal fuselage of conventional aircraft, the extensive use of composite materials in aircraft fuselage has led to changes in the grounding grid structure within the aircraft composite area. In order to analyze the current distribution in the composite aircraft grounding grid accurately, the complex grounding grid structure elements is replaced by the wire model, and the structure of composite aircraft grounding grid is built based on the wire model.By injecting current into the structure, the influence of current frequency, connecting material between skin and grounding grid structure on current distribution of grounding grid structure is analyzed.The simulation results show that for large composite aircraft grounding grid structure, before a certain frequency,the current distribution on the grounding grid structure is subject to the resistance effect, when the frequency exceeds a certain limit, the impedance on the grounding grid structure will be greater than the composite skin impedance, and the current distribution is subject to the inductance effect.