View Video Presentation: https://doi.org/10.2514/6.2022-1117.vid
Thin-ply composites are a novel design material that can be utilized in lightweight structural elements in space applications. The limited volume in the satellite requires the structural components to be folded and stowed for long periods of time before being deployed into the service configuration. Therefore, the design should ensure that materials do not result in irreversible deformation during folding and stowage. However, the conditions for yielding and accumulated permanent deformation have not been investigated. This paper presents an experimental study to characterize the permanent deformation of epoxy polymer and thin-ply composite laminates. A tensile loading-relaxation-recovery test was performed to determine the yield point and plastic strains of a thermoset epoxy. The permanent shape change of a composite laminate made from the same epoxy matrix reinforced with plain-weave carbon fabric under constant curvature bending was characterized using full-field displacement measurements. The permanent residual curvature of the laminates subjected to two different relaxation conditions were compared. It is found that a longer bending relaxation period results in an increase in permanent curvature.
