A study was conducted to investigate the failure characteristics of thermoplastic composite graphite/polyetheretherketone (Gr/PEEK) at 250°F (121°C). The stacking sequences of specimens used in the study were [0°]16, [90°]16, [-45°]4~, and [0°/_+45°/90°]2 s. Specimens of the first three ply layups, namely, [0°]16, [90°]16, and [ _+ 45°]~, were used to determine the basic stress-strain data at
... [Show full abstract] 250°F (121°C). In addition, specimens containing a hole (one-third diameter to width ratio) corresponding to all the four stacking sequences were manufactured to determine the stress-strain response, the progression n of failure, and ultimate tensile strengths. Testing the specimens with ply layups of [-45°]4s and [0°/_+ 45°/90°]2 s containing-+ 45 ° plies was complicated by the development of high strains, thereby causing the strain gages to peel off during tests.