Comparative evaluation of the electrical configurations for the two-dimensional electric potential method of damage monitoring in carbon fiber polymer–matrix composite

Abstract

The effectiveness of the two-dimensional electric potential method of damage sensing in a quasi-isotropic carbon fiber polymer-matrix composite depends on the electrical configuration, i.e., the current direction relative to the surface fibers and the electrical contact scheme. Oblique current application in any direction provides effective damage sensing, as shown by using electrical contacts on the opposite in-plane surfaces. In-plane current application through the cross section in any direction also provides effective damage sensing, as shown by using electrical contacts that are either on the edge surfaces or in holes through the composite. In-plane surface current application is effective when the current is perpendicular to the surface fibers (due to the low resistivity in the direction of the fibers) and is ineffective when the current is parallel to the surface fibers (due to the high resistivity in the direction perpendicular to the fibers). The oblique configuration is recommended for practical implementation. In general, the potential method is reliable when (i) the resistance between the electric current line and the nearly parallel electric potential gradient line is sufficiently low, as attained when these lines are sufficiently close, and (ii) the resistance between the current line and the damage location is sufficiently low, as attained when the distance of separation is sufficiently small.

Strain and Damage Monitoring of CFRP Laminates by Means of Electrical Resistance Measurement

“…The ultrasonic method failed to detect damage from impact at 0.73J, but the oblique resistance change indicated damage. Wang and Chung (85) investigated the effect of electrical configuration, i.e.…”

Self-sensing and self-healing in composites

“…Extending the previous method, it is possible to combine multiple measurements of the conductivity of the panel to see changes caused by damage (Figure 9.4) [7,30,[67][68][69][70]. In these approaches, a more general measurement of the conductivity is made by measuring from one contact to an array of neighboring contacts.…”

“…The disadvantage is that the complexity of the system is dramatically increased, as the number of measurements needed to map the panel is significantly higher. Two approaches have been undertaken to enable determination of the damage location using these methods, an array of contacts across the face of the panel [67][68][69][70] and edge-mounted contacts [7] (Figure 9.5).…”

Characterization of Carbon Fiber Polymer Matrix Composites Subjected to Simultaneous Application of Electric Current Pulse and Low Velocity Impact

“…As damage increases, the resistance of the specimen increases (Schulte et al, 1989, Angelidis et al, 2005, Wang et al, 2006. This resistance measurement, however, does not perfectly represent the composite sample but also accounts for the contact resistance between the electrode and specimen (Shen, 2007).…”