Evaluation of Notched Strength of Composite Laminates for Structural Design

The use of notched specimens to generate design allowable is common practice among aircraft designers. This article assesses the limitations of open-hole tests and emphasizes the importance of numerical simulations to produce notched strength data for structural design allowable. Using numerical simulations, failure envelopes of open-hole specimens were obtained for two different quasi-isotropic carbon fiber-epoxy laminates, namely, [π/4]: [45/90/-45/0] 4s and [π/3]: [0/ ± 60] 5s . It was demonstrated that open-hole tests produce data that is very limited to the specific loading conditions and, therefore, shall not be directly applied to structural design.