Session: SYMP 5-3: SHM for Extreme Load Applications

Paper Number: 140064

140064 - Utilizing Fbg for Stability and Failure Monitoring of Power Line Transmission Towers Subjected to Hurricane Loads. 

The integrity of the power transmission network is paramount in modern society, with the health of its infrastructure holding significant importance. At the core of the transmission line is the power tower, facing various external forces such as strong winds, land subsidence, cable icing, floods, and earthquakes. Many transmission towers traverse remote and challenging environments, rendering traditional, manual/visual inspection methods ineffective for ensuring real-time performance.

Hence, the establishment of a robust structural health monitoring system becomes crucial for accurately tracking, predicting, and safeguarding against structural issues like collapse or deformation of the tower. This ensures the secure and stable operation of the power grid. Leveraging the corrosion resistance, electromagnetic interference immunity, and high sensitivity, Fiber Bragg grating (FBG) sensors have proven to be an effective solution for real-time monitoring of temperature and strain changes in power transmission towers.

This study focuses on investigating the efficacy of embedding FBG sensors within power transmission towers to measure, collect, and store temperature and strain changes at critical points on the structure.

Given that tower strain changes are influenced by various factors such as temperature, humidity, icing, wind, and ground subsidence, the implementation of a suitable failure estimation algorithm is essential for generating warning reports or estimating structural reliability. A finite element model is used for structural stress analysis to identify critical points when the structure is exposed to strong wind, for attaching FBG sensors. A proof-of-concept experimental setup validates the system's performance and functionality.

Four of the most important failure scenarios were investigated; 1) foundation misalignment to simulate land subsidence, 2) adding external distributed load on cable to simulate icing, 3) wind tunnel to simulate strong wind, and 4) combination of the four loadings. The stability of the tower is estimated using the measured strain and/or change of wavelength of FBG sensors for each loading conditions. Strain and temperature data are collected using surface-bound FBG sensors and transmitted to the processing unit via a low-powered micro FBG Interrogator.  The generated FBG signals used to generate a real time deflection profile of the tower. The FBG signals are also used to estimate the induced stress at critical points. The results are used to estimate the reliability and possibility of failure of the tower. The collected data, following certain patterns, are communicated to a processing unit. The processing unit utilizes the appropriate signal processing algorithm to provide real-time assessments of the structure's performance and reliability, and aim to mitigate the risk of structural failure. The assessment results are used to generate condition-based maintenance, safety, and stability reports as well as issuing real-time failure and damage warnings, enhancing the overall resilience of the power transmission infrastructure.

Presenting Author: Abolghassem Zabihollah Tarleton State University

Presenting Author Biography: Dr. Zabihollah is an associate professor of mechanical engineering Tarleton State University in Texas, USA. He has over 10 years of teaching experience taught many courses in engineering. Research area of Dr. Zabi is smart materials and structure, design optimization and vibration control. He is co-author of 85 research articles in peer-reviewed journal and conference e proceedings. As a professional engineer, he has over10 years’ of experience in mechanical engineering fields including, research and development (R&D), design and commissioning, project management, and maintenance planning. These include; designing HVAC systems for buildings, vibration analysis, structural and stability analysis, stress analysis, technical drawings, and analysis using finite element software.

Authors:

Abolghassem Zabihollah
Rajesh Vuddandam
Haitham Abu-Ghazaleh
Raul Sandoval