Failure assessment on central-sharp notched carbon/epoxy laminates

Fracture models to predict the strength of laminated composites having sharp notches demand the un-notched strength and the critical damage size ahead of the notch. The critical damage size, in general, depends on the material, geometry of the specimen and size of the sharp notch. The extraordinary success of a fracture model lies in its ability to combine a theoretical framework with experimentally measured quantities. Modifications are made in one of the stress-fracture criteria known as the point stress criterion for accurate prediction of notched tensile strength of composite laminates containing sharp notches. To examine the adequacy of these modifications, fracture data of central-sharp notched carbon/epoxy composite laminates with various lay-ups are considered. The notched strength estimates are found to be close to the test results. The modified point stress criterion is very simple and accurate in predicting the notched tensile strength of laminated composites.