Analysis of Ballistic Impacts on Composite materials by Infrared Active ThermographyTuesday (26.05.2020) 18:02 - 18:03
Since the beginning of the last century the ongoing advances in materials engineering have led to an unrestrained development of new technologies. Composite materials are the ones attracting most attention because they have many advantages over their homogeneous counterparts. These include high specific stiffness and high specific strength combined with a significant reduction in weight making them attractive for many industrial applications. One of the most important fields of application is the defense industry were the composites properties such as low weight, rigidity, strength and durability are of key importance. Composite materials made from artificially obtained high strength fibers are particularly interesting. These composites are characterized by many fiber-reinforced properties that make them ideal for ballistic protection applications. The ballistic protection equipment should protect the user from for instance arms fire. The proper analysis strategy of the area of internal damage caused by the impact of bullets is very important in the research and evaluation of protective composite ballistic equipment. Damage to the internal structure of the composite coating material can only be assessed using non-destructive testing methods. This work focused on the assessment of the damaged area on composites ballistic plates subjected to high velocity impact. Active pulsed thermography technique was used for performing post-mortem analysis of the impacted specimens. The post-mortem analysis was combined with inputs of the velocity of the projectile, the absorbed energy to evaluate how efficient the material is at spreading the absorbed energy to a large area. M16 rifle using 5.56 mm caliber bullets was used to fire shots threw a wooden laminate located at a distance of 10 m in front of the firearm. High speed visible cameras were used to measure the projectile velocity before and after the sample, Telops high-speed IR camera was also used. Active thermography experiments were conducted with Telops new NDT solutions called TESTD. Flash lamp source with pulse energy of 6 KJ was used to excite the sample after the ballistic testing. Telops high definition IR camera was used to capture the sample cooling after the pulse heating and Fourier transform analysis were conducted to obtained phase images.