Journal of Nondestructive Evaluation

, Volume 16, Issue 1, pp 43–56 | Cite as

Detection of utility pole rot damage by measuring the reflection coefficient

  • Darryll J. Pines


This paper presents a novel nondestructive approach for determining the presence of rot in wood telephone/utility poles carrying telephone and power lines. The method requires determination of the reflection coefficient of the buried end of the pole using physical point measurements such as position, acceleration, or strain. Wave propagation analysis is used to characterize the one-dimensional structural dynamics of the wood pole. This approach permits directional wave components which propagate up and down the pole to be extracted using a previously developed wave filtering scheme.(1,2) These sensed directional wave components can then be used to compute the local reflection coefficient of a structural discontinuity based on longitudinal, transverse, or torsional excitation. The reflection coefficient yields information about the location and extent of pole rot in wood utility poles. Temporal data of incident and reflected wave components also permits a visual characterization of the effect of pole rot on the structural response of the utility pole. Experimental results are obtained on two laboratory test specimen excited in the axial direction to confirm analytical predictions.

Key words

One-dimensional traveling waves phase closure scattering coefficient pole rot wave estimation matrix 


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Copyright information

© Plenum Publishing Corporation 1997

Authors and Affiliations

  • Darryll J. Pines
    • 1
  1. 1.Department of Aerospace EngineeringUniversity of MarylandCollege ParkUSA

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