Authors: X Zhu F Lanza di Scalea
Publish Date: 2016/08/17
Volume: 56, Issue: 9, Pages: 1599-1610
Abstract
Insitu stress determination in structures without a reference value is a challenging experimental mechanics task especially if it requires a nondestructive approach One potential application of this task is the management of longitudinal loads in railroad structures This paper examines the potential of the ElectroMechanical Impedance EMI method to provide an estimation of axial stress in barlike structures The EMI method is completely nondestructive as it simply involves bonding a piezoelectric element on the host structure and measuring the electrical admittance signature of the PZTstructure assembly in selected frequency bands Analytical models are proposed to relate such admittance signatures to uniaxial applied stress as a function of relevant parameters of the EMI monitoring system These models compare favorably to experimental results obtained from an aluminum bar and a steel bar where appreciable sensitivities of the EMI admittance terms are found under varying stress levelsThis project was partially supported by the US Federal Railroad Administration under grant FRRRD00591401 The Program Manager is Mahmood Fateh from the FRA Office of Research and Development The work was also funded by a PhD Dissertation Fellowship from UCSD to Xuan Zhu
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