Vectran Fiber Time Dependant Behavior and Additional Static Loading Properties
Abstract
Vectran HS appears from literature and testing to date to be an ideal upgrade from Kevlar braided cords for many long-term, static-loading applications, such as tie-downs on solar arrays. Vectran is a liquid crystalline polymer that exhibits excellent tensile properties. The material has been touted as a zero creep product. The testing discussed in this report does not support this statement, though the creep is on the order of four times slower than with similar Kevlar 49 products. Previous work with Kevlar and new analysis of Vectran testing has led to a simple predictive model for Vectran at ambient conditions. The mean coefficient of thermal expansion (negative in this case) is similar to Kevlar 49, but is not linear. A positive transition in the curve occurs near 100 degrees C. Out-gassing tests show that the material performs well within parameters for most space flight applications. Vectran also offers increased abrasion resistance, minimal moisture regain, and similar ultraviolet degradation. The effects of material construction appear to have a dramatic effect in stress relaxation for braided Vectran. To achieve the improved relaxation rate, upgrades must also examine alternate construction or preconditioning methods. This report recommends Vectran HS as a greatly improved replacement material for applications where time dependent relaxation is a major factor. (9 tables, 8 figures, 18 refs.)
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 2004
- Accession Number
- ADA428597
Entities
People
- Marjorie F. Sovinski
- Russell B. Fette
Organizations
- National Aeronautics and Space Administration