روشي جديد براي رديابي ترك در محورهاي دوار، به كمك تغييرات شكل مد

A Novel Way for Crack Detection in Rotors, Using Mode Shape Changes

In this article, a non-destructive method for the frequency analysis and multi-crack detection in rotating shafts is presented, using transfer matrix method (TMM) and based on the Timoshenko beam theory. The cracks can be placed in different angles with respect to each other. The presence of cracks in structures change the local flexibility and results in reduction of natural frequency. The TMM is exerted for the frequency analysis of the shafts with discrepant boundary conditions. The resultant frequencies are used for requiring the mode shapes of the shaft corresponding to the two perpendicular planes (x-z and y-z). Subtracting these two mode shapes gives the position of the crack (cracks). Finally, the required frequencies by TMM are compared with some available experimental results. Close adaptation between these results is representing the high accuracy of the novel transfer matrix method.