Comparison of static and fatigue interlaminar testing methods for continuous fiber reinforced polymer composites

Abstract

Two different interlaminar fatigue testing methods have been compared by testing a carbon fiber reinforced epoxy (CF/EP) composite and a carbon fiber/multiwalled carbon nanotube reinforced epoxy (CF/MWCNT/EP) hybrid nanocomposite. The first, conventional fatigue testing method was the end-notched flexure (ENF) test, which was used as a reference. The second, novel technique was the fatigue interpretation of the double-notch shear (DNS) test. Both tests have been performed with static and cyclic loading to compare the evaluated properties of the different systems, the effect of transition from cyclic to fatigue loading and to demonstrate if the complex ENF test can be replaced by the simpler DNS test. The test results showed the slight beneficial effect of the nanoreinforcement in both static and cyclic load conditions, and the possibility to use the DNS test for fatigue testing of continuous fiber reinforced composites. The SEM micrographs taken of the fracture surfaces of the composites after the different interlaminar tests provide valuable data on the interlaminar failure phenomena of hybrid nanocomposites in both static and fatigue loading conditions.

The effect of temperature on fatigue strength of poly(ether‐imide)/multiwalled carbon nanotube/carbon fibers composites for aeronautical application

“…[18] Thermoplastic laminates have gained prominence in the market, due to their easier processability, superior impact toughness, high-damage tolerance, and higher temperatures of service compared to thermoset structures. [19][20][21][22] Also, thermoplastics matrices exhibit a near-infinite shelf life at room temperature. This compares quite favorably to the shelf life of fewer than 6 months in refrigerated storage for typical prepreg thermoset materials.…”

Circular braided glass fiber/epoxy composites with helical architecture (coil spring) fabricated by plaster‐sacrificial compression molding for structural automotive applications

“…Long FRPC have been used due to their high mechanical stiffness and productivity, despite a drawback of anisotropic properties in the case of external multi‐axial load 8–10 . Continuous FRCP have been used for parts carrying high load, such as structural frames, despite their low productivity 11–14 . Short FRCP with high productivity can be utilized for parts undergoing intermediate amount of stress, such as impellers, brackets, and canisters 15–18 …”