SVSFEM s.r.o. Brno, Czech Republic Technical support for Rotordynamics Ing. László IVÁN, rotor@svsfem.cz
The aim of the project ANSYS has been created as a problem oriented macro based tool which is integrated in ANSYS and makes it easier for the user to deal with rotor vibration problems. The main objective of creation of the tool was to use the maximum of ANSYS capabilities like creation of finite element model, elements library, computational procedures for solution of eigenvalues, mode shapes, harmonic vibration, transition vibration. A problem oriented user environment (UIDL) was created to make input parameters entry, specification of the analysis and results evaluation easy. The module is fully implemented into the environment of ANSYS.
The menu system
Setup of Units The user can define the units by selection from a couple of predefined groups that he would like to use in the analysis. Based on this selection a wizard (non-binding) for input parameters entry will appear, which will shows the units in which the system expects entered values.
Rotor FE model SHAFT (Beam4, Beam189) DISC (Pipe16) SPRING-DAMPER (Combin14) MATRIX27 (Matrix27) MASS (Mass21) BEAM4 BEAM189 PIPE16 MASS21 MATRIX27 COMBIN14
Stiffness-damping properties for COMBIN14 elements Polynomial function Table Stiffness : K(N) = K 0 + K 1 *N + K 2 *N 2 + K 3 *N 3 N -rotor speed [RPM]
Capabilities Static analysis for constant rotor speed Modal analysis Lateral Torsional vibration Damped Undamped analysis Modal analysis for variable rotor speed (Campbell diagram) Critical speed, Stability, Mode shapes Gyroscopic effect Prestress effect
Capabilities Harmonic analysis Lateral Torsional steady state forced vibration Damped Undamped analysis Harmonic analysis the excitation frequency is k multiple of the rotor speed constant rotor speed variable excitation frequency constant excitation frequency variable rotor speed Gyroscopic effect Prestress effect
Capabilities Transient analysis Lateral Torsional forced vibration Damped Undamped analysis Transient analysis Numerical simulation for constant rotor speed Numerical simulatin of transition through the resonance Gyroscopic effect
Future By using the UPF create new elements for nonlinear rotor dynamics. Non-linear coupling elementsbetween rotating and non-rotating parts slide bearings roller bearings squeeze film dampers seals contact model between rotating and non-rotating parts coupling by magnetic field self-lubricating bearing
A rotor with two disks d 1 DISC1 DISC2 d 2 d 3 d 4 1 L 1 L 1 L 2 L 1 K Y,B Y K Z,B Z DISC1 K Y,B Y DISC2 K Z,B Z
A rotor with two disks d 1 DISC1 DISC2 d 2 d 3 d 4 1 L 1 L 1 L 2 L 1 1.10E+09 Kz [N/m] 1.05E+09 2.00E+06 Ky [N/m] 1.60E+06 1.00E+09 1.20E+06 9.50E+08 9.00E+08 0 2000 4000 6000 8000 10000 N = RPM [min-1] Stiffnes K z = 10 9 25 000 n + 3 n 2 Damping B z = 2000 Ns/m 8.00E+05 0 2000 4000 6000 8000 10000 N = RPM [min-1] Stiffnes K y = 10 6-100 n + 0,02 n 2 Damping B y = 1000 Ns/m
A rotor with two disks Modal analysis for variable rotor speed (0-10000 RPM)
A rotor with two disks Modal analysis for variable rotor speed Mode 1 f 1 = 10 Hz ( n = 3000 rpm ) Mode 2 f 2 = 23 Hz ( n = 3000 rpm ) f 1 f 2 Mode 3 f 3 = 33 Hz ( n = 3000 rpm ) Mode 4 f 4 = 75 Hz ( n = 3000 rpm ) f 3 f 4
A rotor with two disks Harmonic analysis Y_3 DISC1 Z_3
A rotor with two disks Harmonic analysis f 1 = 10,9 Hz ( n 1 = 654 rpm ) f 2 = 32,8 Hz ( n 2 = 1968 rpm ) f 1 f 2 f 3 = 72,1 Hz ( n 3 = 4326 rpm ) f 4 = 102,9 Hz ( n 4 = 6174 rpm ) f 3 f 4
A rotor with two disks Transient analysis - Numerical simulation for constant rotor speed Impact force Unbalance DISC1 Rotor speed = 1200 RPM Unbalance = 0.0001 kg.m Impact force = 10 N DISC2
A rotor with two disks Transient analysis - Numerical simulation for constant rotor speed
A rotor with two disks Transient analysis - Numerical simulatin of transition through the resonance
A rotor with two disks Transient analysis - Numerical simulatin of transition through the resonance
Users manual + tutorials. Demo version. Technical support. For more informations please contact: www.svsfem svsfem.cz rotor@svsfem svsfem.cz