Creep and interfacial behavior of carbon fiber reinforced epoxy filament wound laminates

This article focuses on the investigation of the interfacial and creep characteristics of carbon fiber-reinforced epoxy laminates at different fiber orientations. Flat unidirectional 12-layer laminates were manufactured by dry-filament winding and cured under hot compression. The following winding sequences were studied: [0](12), [30](12), [45](12), [60](12), and [90](12). Short-beam testing aided by microscopy and dynamic mechanical analysis were used to assess interfacial characteristics and creep behavior of the laminates. Short beam strength and creep behavior were strongly influenced by fiber orientation. Short beam strength decreased 270%, and only the laminates wound at 0 degrees presented delamination purely at the mid-plane. Fiber/matrix stress transfer is more efficient for laminates wound at 0 degrees, providing better creep behavior. Dynamic mechanical analysis results indicated the storage modulus to be dependent on the ply angle. Findley's and Burger's fitting were used to analyze creep data from the DMA and correlate structure and property of the composites. The creep strain increases from longitudinal to transversal fiber orientation and by increasing the temperature. At higher temperatures, samples longitudinally oriented exhibited an elastic behavior, with good agreement with the Findley's model. POLYM. COMPOS., 39:E2199-E2206, 2018. (c) 2017 Society of Plastics Engineers