  Transmission lines, crucial to the power grid, are subjected to diverse
environmental conditions such as wind, temperature, humidity, and pollution.
While these conditions represent a consistent impact on the transmission lines,
certain unpredictable conditions such as unexpected high wind, wildfire, and
icing pose catastrophic risks to the reliability and integrity of the
transmission lines. These factors in the presence of initial damage and
electrical loads greatly affect the material properties. In this paper, we
develop a comprehensive thermo-electro-mechanical model to investigate the
long-term effect of unexpected high wind, wildfire, and ice on transmission
lines. This study offers an in-depth perspective on temperature and damage
evolution within the power lines by incorporating a phase field model for
damage and fatigue, alongside thermal and electrical models. We define a state
function to assess the failure, considering damage and temperature. We study
three scenarios deterministically to establish a basic understanding and
analyze the stochastic behavior using the Probabilistic Collocation Method
(PCM). We utilize PCM for forward uncertainty quantification, conducting
sensitivity analysis, and evaluating the probability of failure. This approach
offers an in-depth examination of the potential risks associated with
transmission lines under unfavorable circumstances.
