The carbon nanofibers and molybdenum disulfide (CNF-MoS₂) nanohybrid material was fabricated and incorporated into epoxy resin to form the nanocomposite coating. Firstly, microstructure observation shows that each CNF was uniformly wrapped up with MoS₂ nanosheets, and the nanohybrids were well dispersed in the coating. Then, nanoindentation experiments were carried out to explore the effect of the CNF-MoS₂ nanohybrids on the mechanical properties of the epoxy resin coating. The results demonstrate that elastic modulus, hardness and creep deformation resistance of the CNF-MoS₂ epoxy resin coating are greatly increased in comparison with both pure epoxy resin and MoS₂ epoxy resin coatings. Finally, the underlying mechanism of high-performance tribological behavior of the nanocomposites is analyzed accordingly. It can be concluded that the wrapped structure with MoS₂ sheets growing on the surface of CNF increases the contact area and reduces the friction coefficient of the composite coating, while the wear resistance of the nanocomposite coating is also greatly improved due to the superior high hardness of CNF.

The bending interlaminar strength and bending interlaminar strength after impact of carbon/epoxy-laminated curved beams were studied experimentally using four-point bending test and low velocity impact. First, the post- impact damage of the laminated curved beams with different radii was analyzed based on ultrasonic C-scan images. Then, the effect of impact damage on both the interlaminar strength and the maximum interlaminar radial stresses of the laminated curved beams were investigated. Finally, the full-field displacement distributions of the laminated curved beams were obtained using digital speckle correlation method. Four-point bending experimental results play a significant role for interlaminar strength in evaluating the laminated curved beams with and without impact damage.

In the acceptance of new bridges and the health monitoring of bridges in service, the deflection is usually considered as the basic parameter that must be measured because it is closely related to the bearing capacity of bridges. The existing bridge deflection measurement methods mainly rely on displacement transducers, dial gauges, connecting pipes, precision levels, digital levels, inclinometers, total stations, microwave radars, global positioning system (GPS), and other measuring equipment, as shown in Fig. 1. Table 1 introduces the typical application scenarios, advantages, and limitations of these deflection measurement methods. It can be seen from Table 1 that the traditional contact measurement methods have certain limitations, which is difficult to achieve dynamic deflection measurement and meet the engineering requirements of real-time measurement and long-term monitoring. In addition, although the accelerometer can also measure the dynamic deflection of the bridge, it has a large error by integrating the acceleration twice to obtain the displacement.^1,2