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Delamination progressive in carbon nanotubes reinforced composites under applied Short Beam Shear test was studied. Experimental characterization was carried out using ASTM D2344 standard norms for different carbon nanotubes mass fractions ranging from 0 to 4%. Failure modes and the delamination were experimentally characterized by scanning electron microscopy and Kayence microscopy to assess the failure behavior. The numerical model was created under ABAQUS software based on the cohesive zone models. The numerical model was formulated according to the damage mechanics. In these models, the cohesive interaction was implanted between elements of each fabric ply to control the initiation and the propagation of the delamination for different carbon nanotubes fractions. The force–displacement curves vs. carbon nanotubes added were obtained for the numerical model and shown to be in good agreement with the experimental data. The effect of carbon nanotubes on the progressive delamination was elucidated. [ABSTRACT FROM AUTHOR]

Abstract The overall goal of the research is to develop a composite simultaneously able to absorb mechanical shocks. In this paper, carbon nanotubes (CNTs) based polymers were used to enhance the wave absorption capacity against shock load. The material consists of an epoxy polymer reinforced with various concentrations of CNTs: 1%, 2% and 4 wt%. An experimental procedure was developed for material characterization. The specimen was sandwiched between two steel bars (incident and transmitted bars), with 20 mm in the diameter. The shock wave was generated by a launching device drives the striker to hit 1 bar, and then the wave propagates throughout the specimen. Two strain gauges were placed on the surface of each bar with 1 m of the distance from the specimen surface. The wave intensity was recorded using a data acquisition system (HBM GEN3i model). The full histories of strain, force and the energy absorption during the shock time were measured. With 4% mass fraction of CNTs, the shock wave intensity was reduced to 33.34% compared to 0% of CNTs. The results show also that the specimen with CNTs is able to absorb high energy impacts. [ABSTRACT FROM AUTHOR]