Age Life Prediction of Nylon 66 Parachute Materials. Part 1. Mechanical Properties
Abstract
Losses in mechanical properties of both suspension lines and parachute canopy material from used PX-1 series parachutes are reported. The loss in canopy material strength was found mainly to result from the storage environment while those for suspension lines resulted from a combination of storage and usage. Rates of strength losses for canopy material in storage were predicted using accelerated ageing techniques. These rates were determined for both the PX and T-10 series of parachutes. The calculated rates were found to differ for each parachute type and the current T-10 parachute material was predicted to lose less strength than the earlier PX type at the same storage temperature. Daylight exposure studies on the same materials showed the reverse trend with the T-10 series being more easily degraded than the PX series. Tensile strength measurements done on suspension lines from used parachutes gave strength losses larger than those expected from storage temperature oxidation. This increased loss was considered to result from shearing of nylon filaments by accumulated abrasive material. Acoustic emission during line fracture supported this type of failure. Low temperatures had a negligible effect on suspension lines. The energy absorbing characteristics of the lines remained reasonably constant over the temperature range of -40 deg C to 22 deg C.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1984
- Accession Number
- ADA147698
Entities
People
- G. A. George
- G. T. Egglestone
Organizations
- Defence Science and Technology Group