THE USE OF WIRE STRAIN GAGES TO DETECT SOME TYPES OF SPLITTING FAILURE IN NOTCHED COMPOSITES

Document Type : Original Article

Author

Assist Professor of Mechanical Design and Head, Design with Innovative Materials Group, Military Technical College, Cairo, EGYPT.

Abstract

Two experimental investigations have demonstrated the extreme usefulness of using wire strain gages in studying the mechanical behavior of com-posites. Wire strain gages have also shown their capacity in detecting some splitting failure types in notched composites under tensile loads. The first investigation entailed notched [07 8 unidirectional graphite/epoxy composites. An arrangement of wire strain gages around the notch boundary has easily detected the onset ofsplitting damage in the specimen. Splitting damage is through-the-thickness matrix cracks emanating from the notch tips and propagating along the filament direction. The second investigation entailed notched [0/145°Js graphite/epoxy laminates. Splitting damage in both the 0° and 45° plies have been identified using a modified gage arrangement.