Modeling the influence of periodic loads on snow detachment from suspended cables

摘要

Disasters to transmission lines due to wet snow events motivate researchers to carry out advanced dynamic analysis in order to understand and predict the line transient response to complex dynamic loads. The interest of numerical modeling of the effects of snow shedding phenomena is to check whether the amplitude of the induced motion is within the design limits of electrical clearances with the ground or with other conductors. This paper aims to develop a numerical model to consider wet snow adhesion on transmission line cables, and consequently, to predict snow shedding from cables due to dynamic effects. The finite element analysis software ADINA is used to simulate the nonlinear dynamic response of a snow-covered cable to the application of periodic loads and subsequent effects of snow shedding. Comparison of model results and small scale experimental simulations is used to validate the model. The model predicts cable rebound height following the application of different periodic loads as well as different snow shedding scenarios. It is found that for highest adhesion, snow sheds only at high excitation frequencies, whereas the inverse occurs for low adhesion. Cohesion force between the snow particles is greater than its adhesion strength to the cable. For large snow thickness, it is rather difficult to obtain snow shedding comparing to the small thickness.