Space Environment Effects on Damping of Polymer Matrix Carbon Fiber Composites

Abstract

Theeffectsof thelow-Earth-orbitenvironmentonthemechanical propertiesof somecarbon-reinforcedpolymer matrix composites are reported. Material damping loss factors and glass transition temperatures of control and e ightspecimensweremeasured. Flight specimenswereattached totheleading edgeoftheLongDurationExposure Facility, and control specimens were maintained at the NASA Marshall Space Flight Center. Changes in the glass transition temperatures and damping were due to combined exposure to 1 )atomic oxygen, 2 )UV radiation, and 3 ) thermal cycling. High atomic oxygen exposure during the e nal year of the Long Duration Exposure Facility e ight, however, eroded away much of the material that would have been affected by UV radiation. The glass transition temperatures of the e ight samples were slightly greater than those of the controls, whereas the material loss factors were nearly the same. From a practical point of view, these changes were not very signie cant. However, the relaxation data presented herein may beuseful forunderstandingthedetailsoftheeffectsofthespaceenvironment on composite materials and may aid researchers in developing composites that maintain their properties for extended periods in the harsh environment of low Earth orbit.