TY - GEN
T1 - Experimental and numerical analysis of transversal open cracked shafts considering beam slenderness and crack depth
AU - García-Illescas, Rafael
AU - Gomez-Mancilla, Julio C.
AU - Bregant, Luigi
N1 - Publisher Copyright:
© Springer International Publishing Switzerland 2015.
PY - 2015
Y1 - 2015
N2 - Stiffness variation due to cracks in rotors is a well-known problem; plenty of studies to prevent/avoid catastrophic accidents and rotor bursts exist. FEM numerical results calculating natural modal frequencies for open cracked beams at different notch depths and slenderness ratios, are compared versus experimental laboratory measurements. Shaft beams under simply supported and free-free boundary conditions, focusing on solids and Timoshenko beam finite elements, are studied. Timoshenko beams employ the Mayes and Davies equivalent-length concept for crack modeling. Notched shafts provide useful upper bound frequency reductions values (breathing cracks display up to, and smaller decrements). Modal frequency splitting for each natural frequency are confirmed and validated by numerical simulation and tests. Modal frequencies splitting functions are given, obtained by simulation and experiments which reflect strong crack depth and slenderness ratio influences. Vibrational coupling energy of the frequency splitting reaches a maximum when the excitation is orthogonal to the crack orientation, conclusions are given.
AB - Stiffness variation due to cracks in rotors is a well-known problem; plenty of studies to prevent/avoid catastrophic accidents and rotor bursts exist. FEM numerical results calculating natural modal frequencies for open cracked beams at different notch depths and slenderness ratios, are compared versus experimental laboratory measurements. Shaft beams under simply supported and free-free boundary conditions, focusing on solids and Timoshenko beam finite elements, are studied. Timoshenko beams employ the Mayes and Davies equivalent-length concept for crack modeling. Notched shafts provide useful upper bound frequency reductions values (breathing cracks display up to, and smaller decrements). Modal frequency splitting for each natural frequency are confirmed and validated by numerical simulation and tests. Modal frequencies splitting functions are given, obtained by simulation and experiments which reflect strong crack depth and slenderness ratio influences. Vibrational coupling energy of the frequency splitting reaches a maximum when the excitation is orthogonal to the crack orientation, conclusions are given.
KW - Beam slenderness
KW - Crack depth
KW - FEM
KW - Modal frequencies splitting
KW - Notched open crack
UR - http://www.scopus.com/inward/record.url?scp=84937421263&partnerID=8YFLogxK
U2 - 10.1007/978-3-319-06590-8_27
DO - 10.1007/978-3-319-06590-8_27
M3 - Contribución a la conferencia
AN - SCOPUS:84937421263
T3 - Mechanisms and Machine Science
SP - 347
EP - 359
BT - Proceedings of the 9th IFToMM International Conference on Rotor Dynamics
A2 - Pennacchi, Paolo
PB - Kluwer Academic Publishers
T2 - 9th IFToMM International Conference on Rotor Dynamics, 2014
Y2 - 22 September 2014 through 25 September 2014
ER -