Scientists at Novosibirsk State Technical University (NETI) are developing a software package for calculating the mechanics of core and shell structures, which can be used to solve many practical tasks. One of the applications of the program simulates the operation of a snow relief device and dampens vibrations of power line wires to reduce the likelihood of a breakage.
"There is such a phenomenon on an overhead power line — wire dancing (galloping), when under certain weather conditions (strong wind, snow sticking) vertical oscillations with a large amplitude occur. This can lead to adverse consequences, including the breaking of wires and the destruction of the supports themselves. In addition, defects accumulate due to dynamic loads that are not fully considered in the design. To dampen such vibrations, dampers (vibration damping devices) are placed on the wires. By order of one of the large electric grid companies, we have created a program that calculates the optimal parameters of a special damping device," said Dmitry Krasnorutsky, Associate Professor of the Department of Aircraft Strength at NSTU-NETI, Ph.D. in Engineering.
The software package consists of a computing core and additional modules for preparing the initial data and processing the calculation results combined into a graphical interface. The initial data is set based on technical documentation and operating conditions.
"We are creating a mathematical model of the transmission line support according to the drawings. To reduce computational costs, we reduce (simplify) the model while maintaining the basic dynamic characteristics. The fluctuations of a single dynamic system consisting of several models of supports with wires are calculated under the influence of operational loads, such as, wind and impulse influences, as well as the weight of wires with an air hoar. To simulate the operation of an automatic snow relief device and damping of wire vibrations, the program determines the optimal parameters of the damper: the stiffness of the spring and the viscosity of the damping element — the effectiveness of damping vibrations depends on this ratio. When snow adheres, the flow of air around the wire becomes worse, additional aerodynamic loads appear, leading to dancing, and such a wire is more prone to breakage. Therefore, when a certain weight of the wire is reached, the device generates a wave of mechanical disturbance that dumps snow," Dmitry Krasnorutsky added.
It is planned to further develop the graphical interface to increase its functionality and expand the range of users in the industrial sphere.