INFRARED THERMOGRAPHY METHOD USED TO INVESTIGATE COMPOSITES DESTRUCTION IN PERSONAL BALLISTIC PROTECTIONS

Abstract

The paper presents problems related to determining the damage area of material caused during destructive tests of multi-layer aramid composites used in ballistic protection. In order to estimate the size of the composite damage area, tests were performed to record changes of the temperature fields on the composite surfaces using two IR cameras during shooting. The standard fragments and bullets used during ballistic protection tests were used. On the basis of the thermograms recorded during the shooting, temperature graphs of the front and rear surfaces of the composite were prepared along the damage caused by the shot. Based on the results obtained, the damage areas within the composite around points of projectiles impact were estimated, that could be much larger than loss of material visible by unarmed eye. In addition, it was found that the material damage area at the back of the ballistic shield is larger than the projectile impact side. According to national standards points of projectiles impact should not be located in material weakened areas caused by previous shots. Hence, the problem in question requires extensive testing to find out if the established distance between hits should be increased and if it is possible due to the limitations of the dimensions and construction of the ballistic protection.