Published Online: 29 August 2013
Page Count: 7
Professor of Civil Engineering, Director of Center for Innovative Grouting Materials and Technology (CIGMAT), Director of Texas Hurricane Center for Innovative Technology (THC-IT), Dept. of Civil and Environmental Engineering, Univ. of Houston, Houston, TX
Graduate student, Dept. of Electrical and Computer Engineering, Univ. of Houston, Houston, TX
(Received 10 August 2012; accepted 19 April 2013)
In this study, self-monitoring characteristics of a new piezoresistive structural polyester polymer composite bulk sensor were investigated under various loading conditions using impedance spectroscopy (IS). IS was used to estimate the bulk resistance of the piezoresistive polymer composite and the contact resistance of the two-probe measuring system used, along with the stress and shape dependence of these resistances. The piezoresistive behavior of cylindrical specimens in compression and circular disk specimens in bending and splitting tension showed repeatable characteristics. The contact resistances were about 1 % and 4.4 % of the bulk resistances for the cylindrical and circular disk specimens, respectively. The contact resistances were relatively small compared to the bulk resistances, and the change in contact resistance with applied stress was quantified. The average piezoresistivity coefficient for cylindrical specimens was 0.015 MPa−1 in compression, and for the circular disk specimens the coefficients were 3.1 × 10−4 MPa−1 and 4.62 × 10−4 MPa−1 under bending and splitting tensile loading, respectively. An incremental stress-resistivity model was used to predict the observed behavior of the piezoresistive polymer composite.
Paper ID: JTE20120249