SIMULATION OF ICE-SHEDDING ON ELECTRICAL TRANSMISSION-LINES USING ADINA

Overhead power transmission lines are subject to various static and dy namic loads. Among the dynamic loads treated quasi-statically in the l ine design process are imbalances due to the sudden fall of ice accret ed on conductors and ground wires, a phenomenon known as ice-shedding. In order to study the static and dynamic effects of this physical phe nomenon on towers as well as on phase-to-phase and phase-to-tower spac ing, a series of laboratory tests were conducted on a two-span reduced -scale setup representing two level, equal conductor spans anchored at the end points and suspended in the middle by an insulator string. In these experiments, ice-shedding loads were simulated by suddenly drop ping dead-weights from the conductors. Concurrently, a nonlinear finit e-element model using ADINA was developed to simulate the static and t ransient dynamic responses of the physical model. This paper describes the essential characteristics of the numerical model and compares its predictions with the experimental results from a typical case. The co mparison shows the good performance of ADINA in modelling the static a nd transient dynamic responses of this highly nonlinear engineering ph enomenon.