Page History

...

Joint Factor: "a 'loss in joint strength…relative to the basic material strength' that occurs when 'textiles are connected to each other or to metals.'”

Warp fibers: "fibers of a textile that carry the majority of the load and are in the direction of the load axis"

Fill fibers: "the fibers whose primary purpose is to organize the structure and facilitate load sharing"

Image Removed

Image from https://ntrs.nasa.gov/api/citations/20150003409/downloads/20150003409.pdf

3 Parachute materials:

Cord: Typically braided
Tape/Webbing:typically woven, warp and fill fibers
Cloth: typically woven, warp and fill fibers

This method of testing analyzes the strength of these joints to obtain the joint factor, which is The ideal situation would have the stitches break before the material itself, showing that the material's strength is being used at its fullest..

" In most cases, the joints being tested are sewn. Occasionally, components are joined with a looped connection or tied. Joints between textiles and the spacecraft structure (typically metal pins) are also tested using accurate interface geometry." Tests are meant to analyze one joint at a time.

Image Added

Since we do not have one of these machines, a modified version using our Instron machine would be advised to perform these tests.

Fore more specific testing procedures and designs go to pages 9-12: For an in depth look of joint testing check out: https://ntrs.nasa.gov/api/citations/20150003409/downloads/20150003409.pdf

Extra info: https://arc.aiaa.org/doi/abs/10.2514/6.2017-4200#:~:text=A%20parachute%20joint%20is%20defined,called%20seam%20and%20joint%20testing.