Change in failure mode of carbon nanofibers in nanocomposites as a function of loading rate

摘要: Vapor-grown carbon nanofiber (CNF)/epoxy composites are characterized under compression at 5 × 10−3–2800 s−1 strain rates. A difference in the fiber failure mechanism is identified based on rate. CNFs show signs of deformation along their entire length quasi-static compression. In contrast, high-strain rate results rupture outer turbostratic layers, leading to stress transfer inner graphite layers. The graphitic layers elongate and rupture, forming a conical tip fracture cross section CNFs. strength nanocomposites high measured be up 180 % higher depending composite composition substantially increase localized plastic matrix result nanoscale features surface. observed modulus rates attributed mechanisms different