In this work a laser scanning vibrometer has been applied to perform repeated measurements of resonance frequencies and mode shapes of a turbine blade, before and after a structural modification, in order to analyze its effects. It has been demonstrated that, using a laser scanning vibrometer, the effects of structural modification can be measured in very reduced times, which are more or less the same as required for the calculation using a FEM model of the blade. Another important fact is that this measurement technique, because of the low testing time required, allows repetition of the complete tests on same or different blades and it then makes it possible to estimate the probability distribution of model parameter values by repeated measurements. This is very important for the reliability of the evaluation of the risk of resonances during operation and for the experimental evaluation of the effects of a structural modification
Experimental tuning of resonance frequencies of a turbine blade by a laser scanning vibrometer
ROSSI, Gianluca;
1998
Abstract
In this work a laser scanning vibrometer has been applied to perform repeated measurements of resonance frequencies and mode shapes of a turbine blade, before and after a structural modification, in order to analyze its effects. It has been demonstrated that, using a laser scanning vibrometer, the effects of structural modification can be measured in very reduced times, which are more or less the same as required for the calculation using a FEM model of the blade. Another important fact is that this measurement technique, because of the low testing time required, allows repetition of the complete tests on same or different blades and it then makes it possible to estimate the probability distribution of model parameter values by repeated measurements. This is very important for the reliability of the evaluation of the risk of resonances during operation and for the experimental evaluation of the effects of a structural modificationI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.