Method to Improve Post Impact Compressive Strength in Graphite/Epoxy CompositeMaterials After Low Temperature Impact

摘要

A study was performed to investigate a method to improve the post impactcompressive strength in graphite/epoxy composite materials due to low temperature impact. Aerospace quality 32 ply quasi-isotropic IM6/3501-6 test panels were utilized in the study. These panels were modified by adding FM300 interleafs, which have greater impact toughness, over the zero degree piles in four different locations in the symmetric layups. Ultrasonic C-scan inspections were used to characterize the quality of the panels, and provided a basis for comparison after the panels were impacted. The panels were impacted at -67 deg F by an instrumented impactor that produced load versus time and energy versus time curves. A compression after impact (CAI) test was performed to determine the post impact compressive strength of the panel. The results of the compression after impact test, post impact ultrasonic inspection, and optical microscopy were usd to determine fracture-mode and effects of interleafs.