Comparison of the Electrical Resistance and Potential Techniques for the Self-sensing of Damage in Carbon Fiber Polymer-Matrix Composites

Abstract

The electric potential method, which involves measuring the potential at a distance from the line of current application, is effective for damage sensing of carbon fiber polymer-matrix composites when the distance is sufficiently small, such as 1.0 mm (8 laminae) in the through-thickness direction. It is ineffective when this distance is 2.1 mm (16 laminae). The electrical resistance method, which involves measuring the potential on the line of current application, has no thickness limitation. However, it suffers from current path distortion upon damage and the consequent reduced sensitivity for damage. A minor phenomenon of the measured resistance decreasing with increasing damage is observed for the regions of the composite not containing the point of impact. The major phenomenon of the resistance increasing with damage overshadows this minor phenomenon for the region containing the point of impact.

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

“…Corresponding results for the 90 • orientation (not shown) show large and non-systematic variation of the potential gradient with impact energy for impact at P, Q or R. Thus, the damage sensing failed for the 90 • orientation. Large and nonsystematic variation had been previously observed when the current and potential gradient lines are at a distance of 2.1 mm or more in the through-thickness direction [37]. .…”

79 Experimental Assessment of Single and Cumulative Impact Damage in Carbon Fiber Polymer Matrix Composites Using Electrical Resistance Measurements

“…There have been a number of studies on the electrical characterization of carbon fiber polymer matrix composites conducted in the past [1][2][3][4][5][6][7][8][9][10][11][12][13] that attempted to monitor changes in the electrical resistance and electric field that occur as a result of mechanical damage. Two main techniques have been employed to sense impact damage: the potential method and the resistance method.…”

“…The difference between the methods lies in the direction of the potential measurement. In the resistance method, the applied current line and the electric potential line coincide, whereas in the potential method, they do not [4,13]. To sense the damage distribution, the one-dimensional resistance method is adequate.…”

“…In most of the damage sensing via the one-dimensional resistance method research, narrow specimens with widths of 10 or 12 mm have been used [4,[6][7][8]11,12]. Such specimen widths have been used to obtain large resistance measurements and high sensitivity.…”

An experimental investigation into multi-functional Z-pinned composite laminates

“…On the other hand, it has been demonstrated that un-pinned conductive (carbon fibre reinforced) laminates have a strain/damage self-sensing capability, which can be exploited via electrical resistance (ER) or electric potential measurements [30][31][32]. It is worth stressing that "self-sensing" is here intended as the inherent capability of a laminate to generate a detectable change in electrical signal whenever damage occurs, without the need for additional sensing elements.…”