Primary positioning method for added mass of girder structure based on frequency

Abstract

The invention discloses a primary positioning method for the added mass of a girder structure based on the frequency. The method comprises the steps that the natural frequency in front of and behind the added mass of the girder structure in first M (M>=5) frequency orders is measured, and frequency relative change rates are calculated and normalized; a frequency characteristic curve, caused by theadded mass, of the girder structure is calculated; according to the normalized frequency relative change rates and the frequency characteristic curve, the position index of the added mass of each single frequency order of the first M frequency orders is calculated, and all the position indexes are fused to obtain an integrated position index of the added mass; the added mass is primarily positioned according to an occurring position of a peak value of the integrated position index of the added mass. The method can be used for analyzing the natural frequency in front of and behind the added mass of the girder structure and achieving primary positioning for the added mass.

Description

technical field [0001] The invention discloses a frequency-based preliminary positioning method for additional mass of a beam structure, and specifically relates to the technical field of state monitoring of beam structures. Background technique [0002] Beam structures, such as fan blades, are prone to produce additional masses such as snow and ice when they serve in cold environments. If these additional masses cannot be detected and dealt with in time, they will affect the safe and reliable operation of the overall structure. In this context, some non-destructive testing techniques have developed rapidly in recent years and have been used to detect the additional quality of structures. Non-destructive testing techniques such as ultrasonic testing have been applied to additional quality testing of beam structures. However, these non-destructive testing techniques are local testing methods, and generally need to predict the approximate position of the additional mass, whic...

AI Technical Summary

Problems solved by technology

However, these non-destructive testing techniques are local testing methods, and generally need to predict the approximate position of the additional mass, which is difficult to meet in practical applications.

As the overall modal parameter of the structure, the frequency is combined with the frequency characteristic curve of the beam structure caused by the additional mass to form an additional mass position index. The research on the preliminary positioning of the additional mass of the beam structure has not been reported yet.

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