| Popis: |
In order to obtain accurate values of the natural frequencies of torsional vibration of long steam-turbine blades it is necessary to determine the torsional stiffnesses of the blade accurately. Various empirical formulae are at present available for the calculation of the torsion constant for sections such as those of a turbine blade; to determine which is the best, a range of sections has been tested including prismatic bars as well as an actual blade. One particular formula is suggested for use. Additionally the positions of shear-centre and centre-of-twist of some of the bars were found. |
