Patent ID: 7500299

Claim:
A method for introducing a deliberate mismatch into a turbomachine bladed wheel so as to reduce vibration amplitudes of the wheel in forced response, the method comprising the steps of: determining an optimum value of the standard deviation for the mismatch as a function of operating conditions of the wheel inside the turbomachine, with respect to the maximum vibration amplitude response required on the wheel, and at least partly placing blades with different natural frequencies on said wheel such that the standard deviation of the frequency distribution of all blades is equal to at least said mismatch value, wherein said mismatch value is determined statistically including the following steps: defining a first value of the mismatch standard deviation σ j , generating a statistically significant number R of random mismatch distributions within said standard deviation σ j , for each of the R random distributions, calculating the forced mismatched response as a function of the operating conditions of the wheel inside the turbomachine, extracting from the forced mismatched response a maximum value, choosing another value of σ j , and repeating said calculating and extracting steps a sufficient number of iterations to obtain response values as a function of the values σ j .