METHOD FOR EVALUATION OF COORDINATE, LENGTH AND DEPTH OF OPEN FRACTURE OF FLEXIBLE CANTILEVER Russian patent published in 2011 - IPC G01N19/08 

FIELD: machine building.

SUBSTANCE: there are excited bending self-oscillations of reference and analysed cantilevers. Also, for determination of coordinate, length and depth of open fracture of flexible cantilever there are measured the first three frequencies Ω₁, Ω₂, Ω₃, and Ω₁*, Ω₂*, Ω₃* of self-oscillations of the reference and analysed cantilevers correspondingly. Further, from the frequency equation made for a model beam without a fracture, there is determined value of its first three frequencies ω₁, ω₂, ω₃ of self-oscillations. Through ratio of values of corresponding frequencies of oscillations of the model and reference cantilevers without fractures there are found three frequency coefficients k₁, k₂, k₃ of reference of model correction: k₁=ω₁/Ω₁, k₂=ω₂/Ω₂, k₃=ω₃/Ω₃, there are multiplied measured values of the first three frequencies Ω₁*, Ω₂*, Ω₃* of self-oscillations of analysed cantilever with an open fracture to corresponding frequency coefficients of correctness, and there are found exactly the values of the first three frequencies ω₁*=k₁/Ω₁*, ω₂*=k₂/Ω₂*, ω₃*=k₃/Ω₃* of self-oscillations used in the frequency equation on the model cantilever with a cut for calculation of its coordinate, length and depth corresponding to coordinate, length and depth of open fracture of analysed flexible cantilever.

EFFECT: determination of coordinate and dimension of open fracture of flexible cantilever.

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