A series of tests was conducted to measure the strength of stitched carbon/epoxy composites containing through-thickness damage in the form of a crack-like notch. The specimens were subjected to three types of loading: pure bending, pure tension, and combined bending and tension loads. Measurements of applied loads, strains near crack tips, and crack opening displacements (COD) were monitored in all tests. The transverse displacement at the center of the specimen was measured using a Linear Variable Differential Transformer (LVDT). The experimental data showed that the outer surface of the pure tension specimen failed at approximately 6,000 microstrain, while in combined bending and tension loads the measured tensile strains reached 10,000 microstrain.Palmer, Susan O. and Nettles, Alan T. and Poe, C. C., Jr.Langley Research CenterCRACK OPENING DISPLACEMENT; EPOXY MATRIX COMPOSITES; NOTCHES; BENDING; CARBON; CRACK TIPS; TRANSFORMERS; COMPOSITE MATERIALS; LOADS (FORCES); TENSILE TESTS; NOTCH TESTS
