Лако-красочные материалы — производство

Amanda et al., [15] established a technique which holds promise for detecting damage and evaluating different failure modes in adhesively-bonded composite-to-metal single-lap shear joints. They compared electrical resistance data using carbon nanotubes in adhesive with AE and found good agreement.

Carbon nanotubes (CNTs) have found many applications due to their high aspect ratio, high specific stiffness and strength, and excellent electrical and thermal conductivities. In addition to these, carbon nanotubes have enabled their use in sensors and actuators [16, 17].

As a result of their high aspect ratio and electrical conductivity it has been established that carbon nanotubes can form electrically conductive networks in epoxy adhesives and polymer matrix materials and ultimately make them electrically conductive which triggers the opportunity to develop in-situ SHM method. Another important factor is that the addition of carbon nanotubes served to increase the bonding strength and durability of epoxy joints [18].

Thostenson et al., [17] demonstrated that the electrical conductive network formed by CNTs in an epoxy enables to detect the onset, nature and evaluation of damage. In their tests on epoxy/nanotube specimen, they observed that, the electrical resistance of the specimen has linear relationship with the specimen deformation and sharp increase of resistance due to crack initiation.

In another study, Thostenson et al., [19] studied the effect of nanotube concentration on the electrical properties of epoxy and established that percolating networks can be formed at concentrations below 0.1 wt.%. In another investigation, the effectiveness of a carbon nanotube network in quantitatively measuring the onset and progression of damage in real time in — situ monitoring of a reinforced composite is demonstrated [20]. Nofar et al., [21] reported the sensing capability of CNT network in detecting the failure region in laminated composite subjected to static and dynamic loading. They concluded that the CNT network is more sensitive in detecting and predicting the cracked regions than strain gauges due to existence of CNT network throughout the structure as whole rather than locally attached strain gauges. In a more recent study, Amanda et al., [15] suggested an SHM technique by CNT networks to sense and detect damage and evaluating different failure modes in adhesively-bonded composite-to-metal single-lap shear joints.