| Popis: |
In order to study the lightning protection effect of copper wire mesh on composite materials, two different lightning current waveforms were used to simulate the lightning current impact test on composite specimens with and without copper wire mesh in different sizes. Through visual damage observation, optical microscope amplification and ultrasonic damage scanning, the lightning damage degree and characteristics of composite materials were compared and analyzed. The experimental results show that when the lightning current waveform is 1 and peak currents are 50 kA and 80 kA, the lightning strike damage area and depth of the Type1 specimen without copper wire mesh are 1785 mm2, 0.63 mm and 3041 mm2, 0.96 mm respectively, while the test specimens with copper wire mesh in the same type are basically scatheless. When the lightning current waveform is 2 and the peak current is 40 KA, the lightning strike damage area and depth of the Type2 specimen without copper wire mesh are 2156.75 mm2, 0.36 mm, while the damage area of the test specimen with copper wire mesh in the same type is less than 100 mm2, and the inner layer has not been damaged. There exists a threshold value for the maximum lightning current strength of the 0.25 mm copper wire mesh, which can be expressed by the action integral. The lightning protection effect is independent of the specimen size, and is only related to the action integral, the corresponding threshold value of which is about 85218 A2·s. |
