OPERATING RANGE RESPONSIVENESS DEFINITION OF LUMINESCENT SMART COATING BY RESULTS OF IMPACT DAMAGES PARAMETERS ULTRASONIC MEASUREMENTS

Abstract

One of the characteristic aircraft damages is impact by foreign object. In subsequent operation, the presence of impact damages to airframes made of polymer composite materials (PCM) leads to a violation of their structures and integrities. To avoid accidents it is necessary to identify and measure the parameters of such damages. The paper analyzes literature data, impact tests results and ultrasonic control of PCM samples. PCM samples represent plates. Dependences of PCM samples defect size on impact energy are revealed. It is shown that at energy of effect in a range 10…45 J damages with the linear sizes 25…70 mm are formed. The difference of the damages sizes on facing and turnaround surfaces of PCM samples is noted. The largest number of procedures in aviation is visual inspection with the naked eye or using any additional equipment. Its main disadvantage in relation to composite products is the fundamental inability to detect barely visible impact damage and internal defects that do not extend to the surface. The technology of impact damage detection using special impact -sensitive luminescent smart coatings with optical properties allows to improve the visual inspection procedure qualitatively. The result of the research is to define the permissible range of coating sensitivity. The luminescent smart coating operating range is determined: 10…20 J. Luminescent smart coating is developed for detection of barely visible impact damage on composite airframes.