Investigation of the Effect of Moisture on the Mechanical Properties of Organic Matrix Composite Materials Using Nuclear Magnetic Resonance
Abstract
Investigations were conducted of nuclear magnetic resonance (NMR) signals from hydrogen atoms in two organic matrix composite systems subjected to environmental conditioning at 51.6C (125F) and 95% relative humidity. The composite systems were 8 ply, + or - 45 deg laminates fabricated from SP 250 resin/S2 glass fiber and Reliabond 9350 resin/Kevlar 49 fiber. Absorbed moisture free induction decays consisted of distinct multiple components attributed to moisture in various states of molecular binding. Plasticizing of the resin matrix resulted in an increase in nuclear relaxation time with increasing moisture. Good correlation was obtained between the NMR signal amplitude and dry weight moisture percentage for both composite systems. Destructive tensile tests were performed on dried specimens and on conditioned specimens at levels of 4.6% and 1.3% dry weight moisture for the Kevlar and glass composites, respectively. Reductions in ultimate tensile strength due to moisture conditioning were 14% for the Kevlar composite and 4.3% for the glass composite.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1981
- Accession Number
- ADA100426
Entities
People
- G. A. Matzkanin
Organizations
- Southwest Research Institute