4/10/2023 0 Comments Ss109 projectile![]() In future works, it is planned to use this system efforts are currently being made in order to determine its availability. Thermias is based on any high-speed visible light camera, allowing temperature analysis to be carried out in accordance with the speed and resolution of a given camera. The Thermias system, which is a novelty on the market, allows the analysis of ultra-fast phenomena emitting visible thermal radiation. It also seems advisable to look for methods that allow for recording the course of thermal phenomena with higher frequency of image recording. It is necessary to investigate these results in further works and check if this is a numerical issue (disturbance caused by extremely high deformations of finite elements) or if it represents a real phenomenon. The maximum temperature recorded during the calculations was above 3000 ☌, so high temperatures were reached, however only by a few single finite elements. Due to the relatively low recording speed with the thermal camera (660 fps), the most important moment of the phenomenon was observed on only one frame of the recording ( t 0). The fourth frame ( t 3) shows the fragments with a maximum temperature of 488.7 ☌. The next two frames in TCR ( t 1, t 2) show bullet fragments with a maximum temperature of 488.3 ☌. The size of the debris cloud was measured by reading the number of pixels the reference scale was based on the dimensions of the armour plate. After measuring the value of this parameter in thermal imaging (175 mm) we investigated what time corresponded to it on the high-speed camera record (HSCR) ( Figure 6 and Figure 7). The time of the first frame was set as 0.24 ms (238.01 µs), based on the height of the debris cloud. Due to the low number of recorded frames per second it is impossible to determine based on a stand-alone thermal camera record (TCR) when in this recording the phenomenon started (the beginning of the contact of the projectile with the plate). The maximum temperature of 951.4 ☌ was recorded in the first frame ( t 0). ![]() 3.3 m), the thermal camera was located at a safe distance at an angle of 15° in a horizontal plane to the point of impact and at the same height as the direction of the projectile’s flight path.įigure 7 shows the phenomenon using four successive frames, recorded by the thermal camera. In order to not risk damaging the apparatus, and due to restrictions resulting from the specificity of the ballistic tunnel (width of approx. For a thermal camera, this was not possible because due to their insulating properties, the protective elements located in front of it would not allow it to record the actual temperatures. Therefore, the quick camera with protective cover was placed in the desired place during the research (beneficial in relation to the possibility of determining the moment of contact of the projectile with the armoured plate-about 80 cm from the place of impact perpendicular to the side surface/thickness of the steel plate). In the case of a high-speed camera, it is possible to protect it with transparent material such as polycarbonate (PC) or polymethyl methacrylate (PMMA) and record a given phenomenon without distortion. However, due to fragmented elements from the projectile and plate, there is a risk of damage to this apparatus. In order to obtain the best quality image, it is beneficial to place the cameras (fast and thermal) as close as possible to the place of impact of the projectile. The armour plate was set at an elevation angle of 45°, causing an upward ricochet. ![]() A mounting stand, for 500 × 500 × 10 mm Armox 600 armour plate, a Photron Fastcam SA-Z 2100 K high-speed camera, an FLIR X6580sc thermal camera and a 5.56 × 45 mm ballistic barrel were used for the experiment ( Figure 4 and Figure 5). ![]()
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