Evaluation and optimization of a shock load de-icing method for transmission lines with combined ice failure criteria

A mechanical de-icing process for overhead transmission lines using shock load is investigated numerically by finite element analysis, where a combination of three validated ice failure criteria is implemented, namely- the maximum bending strain criterion, the tensile detachment criterion and the shear detachment criterion. A total of 25 numerical scenarios are established and the ice shedding ratio and dynamic response of overhead lines are studied. The goal is to assess the relative importance of the leading parameters that affect the efficiency of the shock-load deicing method and the corresponding transient effects. The parameters under study include: the shock load characteristics (amplitude, time history and applied location along the span), the ice accretion characteristics (equivalent thickness and eccentricity ratio), and the line profile (height difference of span suspension points and adjacent spans). The study leads to suggestions to improve the de-icing efficiency of the shock-load method and reduce the adverse transient effects on the line components. The modeling approach used in this study provides a cost-effective tool and helpful reference for design, evaluation and optimization of a variety of mechanical de-icing methods, devices and procedures.