A novel technology on dynamic interlaminar fracture toughness measurement of composites

Huifang Liu, Hailiang Nie, Chao Zhang, Yulong Li

Composites Sciene and Technology, 2018, https://doi.org/10.1016/j.compscitech.2018.07.040

Hailiang Nie, Tao Suo, Xiaopeng Shi, Huifang Liu, Yulong Li, Han Zhao

International Journal of Impact Engineering, 2018, https://doi.org/10.1016/j.ijimpeng.2018.08.004

Abstract: A novel dual electromagnetic Hopkinson bar was employed to load the DCB specimens dynamically and symmetrically with velocities in the range of 10–30 m/s. A hybrid experimental-numerical method was used to determine the interlaminar fracture toughness for both quasi-static and dynamic loading conditions using the virtual crack closure technique (VCCT). The results indicate the presence of a critical loading rate for interlaminar fracture, below which the fracture toughness remains constant and beyond which the fracture toughness increases rapidly. Fractography results suggest that the failure mechanism transitions from a fiber/matrix interface failure under quasi-static loading to a brittle cleavage fracture of the matrix material with microbranching under dynamic loading.