Gouging phenomenon induced vibrations in the pilot ejection seat test in the sled system

The sled system is the main alternative for evaluation of the performance of ejection seat of high-speed aircraft and fighter jets instead of in-flight testing. This system consists of various components, of which the connection of rails and slipper is one of the most important parts. Using an air-gap between the rail and the slipper allows the sled to track the rail with high speed easier, but may lead to deflection and even overturning of the sled system. Researchers in countries owning this technology have investigated and analyzed the forces transmission between the rails and slipper, and showed that the gouging phenomenon, which causes separation of part of the rails or slipper in the form of tear, can cause intensive vibrations transmission to the sled body. The results of research in this field show that the vibrating environment of the sled test is a linear function of velocity, and surface defects can lead to the gouging phenomenon. Also, the most collision of rails with slipper occurs at the upper part of the rail track and using wire rope dampers inside the propulsion segment, and foam in the inner container of the sled reduces the intensity of vibrations transmitting to the sled.