Dynamic tensile tests of parachute webbing

Abstract

Dynamic-Ioad-stretch and stretch-energy data were obtained for two types of nylon and one type of cotton parachute webbing. These data were compared wit h similar data obtained from static tenRile tests of the materials. The dynamic and static breaking strengths of the web bing were also obtained. The nylon specimens showed a reduced strength, stretch, and capacity for energy absorption under dynamic loading as compared with static loading. The cotton specimens showed under dynamic loading about the same strength, reduced stretch, and increased energy absorption. The energy absorbed by the broken nylon specimens was more t han three times that of the broken cotton specimens.

Impact Phenomena in Textiles

“…In 1945-46 Newman and colieagut.s [63,87] described equipment, of the falling-weight type, to measure the impact rupture properties of nxylon and sisal ropes and of parachute webbing.…”

“…Webbing. -Stang, Greenspan and Newman obtained forceelongation data on two types of nylon and one type of cotton webbinq0 using falling-weight apparatus equipped with a strain gage [87].…”

“…The bar B, however, was made sufficiently long that iz was engaged by the falling weight, thus applying an impact load to the specimen. [63,87], by Schiefer and colleagues, and in the work done for the duPont Company, cited above. The specimen S is supported, from overhead, by a massive, rigid framework.…”

“…In a later modification of this equipment [87], four wire, strain gages were cemented to the surface of the shank if the eye-bolt from which the specimen hung.…”

“…Suitably amplified, this voltage was displayed on an oscilloscope screen and photographed, to give a force-time record. For force measurements on heavier structures, such as webbings, a system of four resistance-wire strain gages was used, substantially in the manner of Stang, Greenspan and Newman [87], described above.…”