DESIGN OF A COMPOSITE MATERIAL ANGLE SAMPLE BENDING TEST FIXTURE

Stress risers in the corner of an angled composite component could affect the structural integrity of a part, due to the laminate being laid up on a small radius. This is especially true if fiber damage or incomplete compaction occurs in the corner during fabrication. This issue arose in conjunction with the development of a composite electronics enclosure. In the composites industry, a rule-of-thumb number for the minimum inside radius of a fabricated part ranges from 0.0625-0.1875 in. However, very little has been published about the effect of the inside radius of a composite part on its load-carrying capability. A test procedure and test fixture that would approximate bending loads in the corner of any angled composite component and allow measurement of failure loads are developed. A graphite--epoxy composite is tested.