Sensing with Carbon Fibres in Polymer Composites

Abstract

Carbon-fibre-reinforced polymer (CFRP) composites derive their excellent mechanical strength, stiffness and electrical conductivity from carbon fibres. The mechanical deformation and electrical resistance are coupled in these fibres that make them inherently sensors. Thus CFRPs can be considered as a self-monitoring material without any need for additional sensing elements. However, for this to become reality the conductivity map of the entire structure needs to be constructed and the relationships between the conductivity and various use-and damage-related variables need to be established. Experimental results demonstrate that internal damage, such as fibre fracture and delamination, decreases the conductivity of composite laminates. In general, the information about the damage size and position can be obtained by utilising electrical impedance tomography (EIT)..

Stress-Responsive Reinforced Polymer Composites via Functionalization of Glass Fibers

“…The fiber component is generally much stronger than the matrix component, allowing the force to be transferred away from the weaker matrix and focused on the fibers . Types of reinforcing fibers including glass, , carbon, − aramid, and natural fibers , are typically incorporated into a polymer matrix. The mechanical properties of the resulting fiber composites can be effectively controlled by fiber type, volume fraction, length, and fiber orientation relative to loading, the polymer matrix chosen, and additional fillers within the matrix. − Among these properties, the load transfer of the “interphase” region between the matrix and the fiber has been considered the most important factor to examine fiber composite properties .…”

“…Types of reinforcing fibers including glass, , carbon, − aramid, and natural fibers , are typically incorporated into a polymer matrix. The mechanical properties of the resulting fiber composites can be effectively controlled by fiber type, volume fraction, length, and fiber orientation relative to loading, the polymer matrix chosen, and additional fillers within the matrix. − Among these properties, the load transfer of the “interphase” region between the matrix and the fiber has been considered the most important factor to examine fiber composite properties . If the interphase region has high bond strength, the resulting fibers will exhibit high stiffness and strength .…”

Optical self-sensing of impact damage in composites using E-glass cloth

“…The field of self-sensing takes a different approach, where the constituents of the composite themselves act as the sensing element. This approach has been demonstrated using electrical means for carbon-fibre composites [5][6][7][8][9], and also optically using the reinforcing fibres in glass-fibre reinforced composites [10][11][12][13][14][15][16].…”

“…Developments of this approach have been made so that localized damage and delamination can be identified and located within the panel area. These have employed surface mounted contacts in an array across the panel, or edge contacts around the panel area [6,7]. Various approaches have been demonstrated, but all identify, locate and quantify the extent of damage within the panel.…”