In order to prevent catastrophic damage in rotating machines, cracked rotors have been widely studied. These rotors present some stiffness variations that can be used to help identify the damage during static or dynamic tests. In this work the important effect of crack depth and beam slenderness on the structural behavior of the shaft is studied. Several numerical models using finite solid elements as well as Timoshenko and Rayleigh beams were elaborated. Numerical results are compared to closed form solutions obtained by classical beams formulation. Transversal crack is modeled by means of equivalent length element introduced by Mayes and Davis. Numerical results are also compared and validated with experimental modal analysis in
1Laboratorio de Vibraciones y Rotodinámica, ESIME Instituto Politécnico Nacional, rrggii@hotmail.com, gomezmancilla@gmail.com México, 2Instituto de Investigaciones Eléctricas, Cuernavaca Mor. México 3Dipartimento di Ingegneria e Architettura, Università degli Studi di Trieste, Italia bregant@units.it, 4Estudiante de doctorado en ESIME IPN
laboratory. With both techniques modal frequencies splitting functions are produced by the crack presence and strongly influenced by the beam slenderness and crack depth. The obtained results are useful for identifying the best conditions for crack damage identification in shafts.
