Sensing Technology for Damage Assessment of Sign Supports and Cantilever Poles

Objective: The objective of this work is to develop and deploy a robust and low-cost sensing technology to assess the structural soundness of sign supports, cantilever poles, and variable message sign (VMS) supports. An analytical model will be initially developed to correlate stress-crack severity and/or location to their structural integrity and residual lifetime. Thus, the sensing technology, by detecting location and size of any defect, will provide a means for PennDOT to predict the residual lifetime and to establish the need for replacement or retrofit. The proposed activities will include efforts in the following areas: finite element modeling, nondestructive evaluation (NDE), structural health monitoring (SHM), fatigue life prediction, and sensor technology development. The project will quantify the dynamic characteristics of in-service structures analytically, and will investigate the effect on the residual structures’ life of stress-cracks located at critical elements. An effective NDE/SHM system will be proposed and developed. Fatigue tests will be performed at the Watkins-Haggart laboratories to validate the analytical model and the NDE/SHM approach. Simultaneously, the system will be tested in the field at locations determined by PennDOT to obtain actual field condition information. The impact of this work on the transportation industry lies on the implementation of a cost-effective strategy that will prevent structural failures that may lead to catastrophic collapses. In addition, the early detection of damage will allow stopping further damage propagation and will prolong the structure’s lifetime by taking appropriate remedial actions such as repair or retrofit.