Dynamic compression and fracture of poly(ether-ether-ketone) under plate impact

Plate impact experiments are conducted to investigate shock compression and spallation properties of poly(ether-ether-ketone) (PEEK) up to a peak shock stress of 2.5 GPa with high-speed velocimetry and postmortem X-ray computed tomography. The Hugoniot equation of state and the shock-state Lagrangian sound velocity of PEEK are obtained via reverse impact. The free-surface velocity measurements indicate two-stage spallation. Spall strength and corresponding tensile strain rates are determined via symmetric impact. Spall strength varies in a narrow range of 0.18-0.22 GPa; it increases with increasing shock pressure as a result of increasing tensile strain rate, reaches a plateau and then drops due to shock heating. With the increasing impact velocity, the fracture toughness decreases monotonically. The compression and fracture features at different impact velocities are likely associated with the rearrangement and breakage of molecular chains.

Automated summary

Plate impact experiments were conducted to investigate the shock compression and spallation properties of PEEK. The study obtained the Hugoniot equation of state and the shock-state Lagrangian sound velocity of PEEK through reverse impact. It was found that the spallation of PEEK exhibited a two-stage behavior and the fracture toughness decreased with increasing impact velocity, likely due to the rearrangement and breakage of molecular chains.