This work concerns the fatigue behavior at three different temperature conditions (−40, 20, and 80°C) and the addition of multiwalled carbon nanotube (MWCNT) into a carbon-fiber reinforced poly(ether-imide) composite. The incorporation of MWCNT into the composite increased the tensile strength and Young's modulus by up 5 and 2%, respectively. At low temperature, the incorporation of the nanoparticles improved the fatigue strength of the laminates by 15%. The shear strength results obtained by interlaminar shear strength and compression shear test tests have shown an increase of about 16 and 58%, respectively, by the introduction of nanotubes into the laminates. Fractographic observations revealed that the surface of carbon nanotube laminate (PEI/MWCNT/CF) presented a ductile behavior, and differences in the fracture aspects of the material compared to the traditional PEI/CF laminate have been observed.

This paper presents the experimental results obtained at prototype scale in the Large Oscillating Water Tunnel (LOWT) facility of WL I Delft Hydraulics with graded sediment subjected to non-linear waves and linear waves plus current flows. The objective of this experiment is to increase our present understanding and physical insight of the basic mechanisms of bed-load and suspended load transport in oscillatory flow conditions when graded sediments are present in the bed. The sediment bed consists of a mixture of two well sorted sands (two fractions) that have been used before in the tunnel in order to make comparisons possible. Net sediment transport rates, time averaged suspended sediment profiles, time dependent concentrations in the suspension and sheet flow layers as well as time dependent velocity profiles are measured. Moreover, the sediment bed composition before and after each test is recorded in order to calculate the transport rate of each sediment fraction. Selected results are presented here. Full details are included in the data report (Hamm et al, 1998). The data will be used for the development of mathematical model formulations for graded sediment transport.