This chapter deals with an analytical approach which may be used to investigate alternatives in the design or redesign process of a line. In particular, this section describes the energy balance principle (EBP) which is used to estimate an upper bound to the expected vibratory motions, gives examples of measured wind and conductor self-damping data used, and some comparisons with available field measurements. Important problems are tackled related to the reliability of available data, investigated through: 1. a critical analysis of the available data pertaining to wind power input; 2. an analysis of data on conductor self-damping; 3. comparison of analytical and experimental vibration measurements; 4. study of how uncertainties regarding wind power input and conductor self-damping are reflected in analytical predictions of vibration behaviour, obtained through the EBP (Energy Balance Principal). These results offer guidance for future research to improve the reliability of such predictions. The main conclusion is that through predictions of aeolian vibration level in operating lines, obtained using the EBP and the various available databases, it is possible to obtain a good reproduction of the frequency range and of the distribution of vibration amplitudes with frequency. If the wind power functions and self-damping models employed in the study are indicative of the range of uncertainty in these parameters, then the range of uncertainty in EBP predictions of vibration amplitude can be about ±50–60%, when steady-state conditions aren’t reached.
Modelling of Aeolian Vibrations of Single Conductors
A. Manenti;Giorgio Diana
2018-01-01
Abstract
This chapter deals with an analytical approach which may be used to investigate alternatives in the design or redesign process of a line. In particular, this section describes the energy balance principle (EBP) which is used to estimate an upper bound to the expected vibratory motions, gives examples of measured wind and conductor self-damping data used, and some comparisons with available field measurements. Important problems are tackled related to the reliability of available data, investigated through: 1. a critical analysis of the available data pertaining to wind power input; 2. an analysis of data on conductor self-damping; 3. comparison of analytical and experimental vibration measurements; 4. study of how uncertainties regarding wind power input and conductor self-damping are reflected in analytical predictions of vibration behaviour, obtained through the EBP (Energy Balance Principal). These results offer guidance for future research to improve the reliability of such predictions. The main conclusion is that through predictions of aeolian vibration level in operating lines, obtained using the EBP and the various available databases, it is possible to obtain a good reproduction of the frequency range and of the distribution of vibration amplitudes with frequency. If the wind power functions and self-damping models employed in the study are indicative of the range of uncertainty in these parameters, then the range of uncertainty in EBP predictions of vibration amplitude can be about ±50–60%, when steady-state conditions aren’t reached.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
