Abstract

Hirth coupling transmits high torques in the rotating assemblies of compressors and turbines. Their mating surface contacts cause local changes in lateral shaft stiffness. This is affected by the teeth geometry, contact surface area, coupling preload, and surface finish at the contact faces. Industry practice ignores localized lateral flexibility from the Hirth coupling, or is guided by limited experience-based rules of thumb. The authors provide a novel modeling approach utilizing 3D solid finite elements which accounts for contact deformations, intricate interface teeth geometries, stress concentration, and surface finish. This provides an increased accuracy localized stiffness model for the Hirth coupling, to improve rotordynamic response predictions. Free–free natural frequencies of a test rotor including a Hirth coupling are experimentally measured. The rotor is instrumented with strain gauges for preload force measurements, and the Hirth coupling contacting surface profiles are measured with a stylus type surface profiler. A GW contact model is obtained from the measured surface profiles. An iterative computation algorithm is utilized to calculate Hirth coupling contact stiffness and contact pressure at the complex-shaped contact surfaces. Predicted and measured natural frequencies are compared versus preload.

References

1.
LiuYuan
,
X.
,
Liu
,
Q. Y.
, and
Gao
,
J.
,
2014
, “
Analysis of the Stiffness of Hirth Couplings in Rod-Fastened Rotors Based on Experimental Modal Parameter Identification
,”
ASME
Paper No. GT2014-26448.10.1115/GT2014-26448
2.
Zhang
,
Y.
,
Du
,
Z.
,
Shi
,
L.
, and
Liu
,
S.
,
2010
, “
Determination of Contact Stiffness of Rod-Fastened Rotors Based on Modal Test and Finite Element Analysis
,”
ASME J. Eng. Gas Turbine Power
,
132
(
9
), p.
094501
.10.1115/1.4000591
3.
Yuan
,
S.-X.
,
Zhang
,
Y.-Y.
,
Zhang
,
Y.-C.
, and
Jiang
,
X.-J.
,
2010
, “
Stress Distribution and Contact Status Analysis of a Bolted Rotor With Curvic Couplings
,”
Mech. Eng. Sci.
,
224
(
9
), pp.
1815
1829
.10.1243/09544062JMES1853
4.
Rimpel
,
A. M.
, and
Leopard
,
M.
,
2020
, “
Simple Contact Stiffness Model Validation for Tie Bolt Rotor Design With Butt Joints and Pilot Fits
,”
ASME J. Eng. Gas Turbine Power
,
142
(
1
), p.
011014
.10.1115/1.4045102
5.
Pisani
,
S.
, and
Rencis
,
J.
,
2000
, “
Investigating CURVIC Coupling Behavior by Utilizing Two- and Three-Dimensional Boundary and Finite Element Methods
,”
Eng. Anal. Boundary Elem.
,
24
(
3
), pp.
271
275
.10.1016/S0955-7997(99)00057-0
6.
Oh
,
J.
,
Kim
,
B. J.
, and
Palazzolo
,
A.
,
2021
, “
Three-Dimensional Solid Finite Element Contact Model for Rotordynamic Analysis: Experiment and Simulation
,”
ASME J. Vib. Acoust.
,
143
(
3
), p.
031007
.10.1115/1.4048556
7.
Oh
,
J.
,
Palazzolo
,
A. B.
, and
Hu
,
L.
,
2020
, “
Stability of Non-Axisymmetric Rotor and Bearing Systems Modeled With Three-Dimensional-Solid Finite Elements
,”
ASME J. Vib. Acoust.
,
142
(
1
), p.
011010
.10.1115/1.4045099
8.
Chaudhry
,
J. A.
,
2011
, “
3D Finite Element Analysis of Rotors in Gas Turbines, Steam Turbines and Axial Pumps Including Blade Vibrations
,” Ph.D. thesis,
University of Virginia
, Charlottesville, VA.
9.
Cook
,
R. D.
,
Malkus
,
D. S.
,
Plesha
,
M. E.
, and
Witt
,
R. J.
,
2002
,
Concepts and Applications of Finite Element Analysis
,
Wiley
, Hoboken,
NJ
.
10.
M. H
,
S.
,
2009
,
Elasticity: Theory, Applications, and Numerics
, Elsevier, Boston, MA/
Academic Press
, Amsterdam, The Netherlands.
11.
Palazzolo
,
A. B.
,
2016
,
Vibration Theory and Applications With Finite Elements and Active Vibration Control
,
Wiley
,
Chichester, UK
.
12.
Greenwood
,
J. A.
, and
Williamson
,
J. B. P.
,
1966
, “
Contact of Nominally Flat Surfaces
,”
Proc. R. Soc. A
,
295
(
1442
), pp.
300
319
.10.1098/rspa.1966.0242
13.
McCool
,
J. I.
,
1986
, “
Comparison of Models for the Contact of Rough Surfaces
,”
Wear
,
107
(
1
), pp.
37
60
.10.1016/0043-1648(86)90045-1
14.
Bhushan
,
B.
,
1998
, “
Contact Mechanics of Rough Surfaces in Tribology: Multiple Asperity Contact
,”
Tribol. Lett.
,
4
(
1
), pp.
1
35
.10.1023/A:1019186601445
15.
Abramowitz
,
M.
, and
Stegun
,
I. A.
,
1965
,
Handbook of Mathematical Functions
,
General Publishing Company, Ltd
,
Toronto, ON, Canada
.
16.
Sherif
,
H. A.
, and
Kossa
,
S. S.
,
1991
, “
Relationship Between Normal and Tangential Contact Stiffness of Nominally Flat Surfaces
,”
Wear
,
151
(
1
), pp.
49
62
.10.1016/0043-1648(91)90345-U
17.
Kessel
,
R.
,
Kacker
,
R.
, and
Berglund
,
M.
,
2006
, “
Coefficient of Contribution to the Combined Standard Uncertainty
,”
Metrologia
,
43
(
4
), pp.
S189
S195
.10.1088/0026-1394/43/4/S04
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