Detection and Location of Ballistic Damage in Composite Materials Using Acoustic Emission Methods

摘要

A method for increasing survivability is described whereby the acoustic emissions generated by ballistic impacts on composite helicopter structural components are recorded and analyzed using a preliminary digital transient data recording test system, the Digital Acoustic Emission System (DAES) and lightweight sensors utilizing polyvinylidene fluoride (PVDF) film. A total of 77 ballistic impacts on six composite test segments using a variety of fragment simulating projectiles (FSP) with different muzzle velocities and impact energies is described. The results verify the capability of the measurement system to detect, locate, and analyze the severity of ballistic impacts. The ratio of the peak RMS value of the output signal from two sensors is shown to be a good indicator of impact energy absorption, or damage severity. Calculated hit locations are found with a mean error of seven percent of the sensor array edge distance.