High-frequency viscoelasticities of CFRP structures by ultrasonic dynamic mechanical analysis

Abstract

In this study, ultrasonic dynamic mechanical analysis (U-DMA) was proposed to directly measure high-frequency viscoelastic properties of carbon fiber-reinforced polymer (CFRP) structures. The representative CFRP structures (unidirectional laminates, cross ply, hybrid laminates, and sandwiches) for engineering applications were fabricated and their viscoelastic properties along the fiber and transverse directions were investigated. It is confirmed that U-DMA method enabled measurements of both basic mechanical properties and anisotropic viscoelasticity of practical CFRP structures in the MHz region. The mechanical properties in different directions of CFRP structures could be distinguished. The experiments were compared with the traditional DMA, tensile tests, and the rule of mixture, and reasonable results are confirmed. Furthermore, the temperature dependence of the high frequency viscoelasticity in the sandwich structure was investigated. Overall, the U-DMA could be used to directly measure basic mechanical properties and anisotropic viscoelasticities of various materials in high-frequency region of MHz.