基于EMA3D 的民用飞机复合材料雷击电流分析

Analysis of Lightning Current in Composite Civil Aircraft Based on EMA3D

摘要:

复合材料具有各向异性低电导率的特性，现阶段大多飞机雷击电流仿真侧重于金属材料的研究，使得复合材料飞机雷击后整机表面电流密度分布和瞬态电流传导无法得到有效表征。为保障民用飞机复合材料雷电防护设计和分析的有效性，将铺层及纤维含量等影响下的各向异性电导率矩阵引入三维时域有限差分法，分析复合材料雷击电流传导原理，并基于EMA3D 仿真软件开展雷击电流分析，以某型等效复合材料蒙皮的民用飞机为对象进行多注入路径下的仿真验证。无防护措施下的结果表明：在击入点的局部区域以及机翼前后缘等尖锐部位的电流密度较大，并出现电流集中现象；自机鼻击入时电流优先沿着机身轴线方向传导，自机翼击入时优先沿着机翼前后缘的展向方向传导；瞬态电流较金属材料民用飞机存在传导滞后性。

Abstract:

The anisotropic low conductivity of composite materials leads to local current concentration and current conduction hysteresis in aircraft after lightning strikes. Currently, most aircraft lightning current simulation methods focus on the study of metal materials, which makes it difficult to effectively characterize the surface current density distribution and transient current conduction of composite aircraft after lightning strikes. To ensure the effectiveness of lightning protection design and analysis for composite civil aircraft, the anisotropic conductivity matrix of composite materials under the influence of various layers and fiber content is introduced into the three-dimensional time-domain finite difference method to analyze the principle of lightning current conduction in composite civil aircraft. EMA3D simulation software is used to analyze the lightning current of composite civil aircraft, which is used to explore the surface current distribution and transient current conduction performance of the composite civil aircraft under multi-channel lightning injection paths. Then, a 3D modeling and simulation of a certain equivalent composite civil aircraft is carried out to analyze the overall current distribution law and transient current change characteristics of civil aircraft under the influence of composite material properties. The results show that: (i) composite civil aircraft may experience current concentration in the local area of the impact point and sharp parts such as the front and rear edges of the wing after being struck by lightning without protective measures, the current density of which is relatively high; (ii) the current preferentially conducts along the axis of the fuselage when composite civil aircraft is struck by lightning at the nose, and the current preferentially conducts along the spanwise direction of the front and rear edges of the wing when lightning strikes from the wing; (iii) the transient current of composite civil aircraft has conduction hysteresis compared to metal civil aircraft.