Rate effects and environmental sensitivity of textile energy absorbers

Textile-based energy absorbers are under consideration for possible use as load-limiting devices for heavy payload tie-down systems in rotorcraft. In the event of a hard landing, these devices could prevent failure of the mounting system and subsequent uncontrolled motion of the payload. A series of environmental conditioning regimens were imposed on the textile load limiters, which are polyester tear webbings and nylon stitch-ripping devices. These test specimens were exposed to ambient conditions, salt-fog spray, isopropyl alcohol, hydraulic fluid, hot water immersion, kerosene, and either high or low temperatures. The results, based on performancemeasures of specific energy absorption, volumetric energy absorption, linear energy absorption, and coefficient of variation of force, demonstrated that the high-temperature conditioning caused the most prominent decrease in performance, whereas the other conditions showed only small variations. Both devices were also tested at rates as high as 15 m/s in ambient conditions. The devices were found to have only a slight reduction in performance under dynamic testing conditions versus quasi-static conditions.