Skip over navigation

 

Mixed-Mode I/II Crack and Electrical Resistance Behaviors of Carbon Nanotube/Polymer Composites

Yasuhide Shindo (Tohoku University), Tomo Takeda (), Fumitsugu Naraoka (), Yu Kuronuma (), Fumio Narita (Tohoku University)

Crack initiation and growth: methods, applications, and challenges

Tue 4:20 - 5:40

Sayles Auditorium

Carbon nanotubes (CNTs) have been considered as suitable candidates for use as nanofillers in polymeric materials to yield next generation multifunctional composite systems. Many researchers have attempted to use CNT-based polymer composites as strain or damage sensors. The principle behind this is that the deformation or the damage initiation and evolution can lead to changes in the electrical resistance of CNT-based polymer composites. These electrical resistance changes provide the possibility of self-diagnostics and real-time health monitoring. In addition, the possible presence of cracks is one of the potential problems. In practical situations, materials and engineering structures are subjected to mixed-mode loading, and deflected or inclined cracks can be encountered. Therefore, a thorough and comprehensive research on the mixed-mode crack behavior and associated electrical response of CNT-based polymer composites is essentially needed. Here, we investigate both theoretically and experimentally the crack and electrical resistance behaviors of CNT-based polymer composites subjected to mixed-mode I/II loading. Fracture tests were conducted on single-edge cracked plate specimens of the nanocomposites under mixed-mode I/II loading conditions. During the tests, the electrical resistance of the specimens was measured. Also, the direction of the mixed-mode crack growth was predicted by a fracture mechanics approach. In addition, an analytical model for describing the electrical resistance change due to inclined crack growth was developed based on the electrical conduction mechanism of CNT-based composites, and the crack sensing ability of the nanocomposites was characterized.