Linear dynamic finite element analysis can be considered very reliable today for the design of aircraft engine components. Unfortunately, when these individual components are built into assemblies, the level of confidence in the results is reduced since the joints in the real structure introduce nonlinearity that cannot be reproduced with a linear model. Certain types of nonlinear joints in an aircraft engine, such as underplatform dampers and blade roots, have been investigated in great detail in the past, and their design and impact on the dynamic response of the engine is now well understood. With this increased confidence in the nonlinear analysis, the focus of research now moves towards other joint types of the engine that must be included in an analysis to allow an accurate prediction of the engine behavior. One such joint is the bolted flange, which is present in many forms on an aircraft engine. Its main use is the connection of different casing components to provide the structural support and gas tightness to the engine. This flange type is known to have a strong influence on the dynamics of the engine carcase. A detailed understanding of the nonlinear mechanisms at the contact is required to generate reliable models and this has been achieved through a combination of an existing nonlinear analysis capability and an experimental technique to accurately measure the nonlinear damping behavior of the flange. Initial results showed that the model could reproduce the correct characteristics of flange behavior, but the quantitative comparison was poor. From further experimental and analytical investigations it was identified that the quality of the flange model is critically dependent on two aspects: the steady stress/load distribution across the joint and the number and distribution of nonlinear elements. An improved modeling approach was developed that led to a good correlation with the experimental results and a good understanding of the underlying nonlinear mechanisms at the flange interface.

References

References
1.
Firrone
,
C. M.
,
Zucca
,
S.
, and
Gola
,
M.
,
2009
, “
Effect of Static/Dynamic Coupling on the Forced Response of Turbine Bladed Disks With Underplatform Dampers
,”
ASME Turbo Expo
,
Orlando, FL
, June 8–12,
ASME
Paper No. GT2009-59905.10.1115/GT2009-59905
2.
Cigeroglu
,
E.
,
An
,
N.
, and
Menq
,
C. H.
,
2007
, “
Wedge Damper Modeling and Forced Response Prediction of Frictionally Constrained Blades
,”
ASME Turbo Expo
,
Montreal, Canada
, May 14–17,
ASME
Paper No. GT2007-27963.10.1115/GT2007-27963
3.
Petrov
,
E. P.
,
2008
, “
Explicit Finite Element Models of Friction Dampers in Forced Response Analysis of Bladed Disks
,”
ASME J. Eng. Gas Turb. Power
,
130
(
2
), p.
022502
.10.1115/1.2772633
4.
Charleux
,
D.
,
Gibert
,
C.
,
Thouverez
,
F.
, and
Dupeux
,
J.
,
2006
, “
Numerical and Experimental Study of Friction Damping in Blade Attachments of Rotating Bladed Disks
,”
Int. J. Rotat. Mach.
,
71302
, pp.
1
13
.10.1155/IJRM/2006/71302
5.
Petrov
,
E. P.
, and
Ewins
,
D. J.
,
2006
, “
Effects of Damping and Varying Contact Area at Blade-Disc Joints in Forced Response Analysis of Bladed Disc Assemblies
,”
ASME J. Turbomach.
,
128
(
2
), pp.
403
410
.10.1115/1.2181998
6.
Chen
,
J. J.
, and
Menq
,
C. H.
,
2001
, “
Periodic Response of Blades Having Three-Dimensional Nonlinear Shroud Constraints
,”
ASME J. Eng. Gas Turb. Power
,
123
(
4
), pp.
901
909
.10.1115/1.1385828
7.
Petrov
,
E. P.
,
2004
, “
A Method for Use of Cyclic Symmetry Properties in Analysis of Nonlinear Multiharmonic Vibrations of Bladed Discs
,”
ASME J. Turbomach.
,
126
(
1
), pp.
175
183
.10.1115/1.1644558
8.
Luan
,
Y.
,
Guan
,
Z.
,
Cheng
,
G.
, and
Liu
,
S.
,
2011
, “
A Simplified Nonlinear Dynamic Model for the Analysis of Pipe Structures With Bolted Flange Joints
,”
J. Sound Vib.
,
331
(
2
), pp.
325
344
.10.1016/j.jsv.2011.09.002
9.
Boeswald
,
M.
, and
Link
,
M.
,
2003
, “
Experimental and Analytical Investigations of Non-Linear Cylindrical Casing Joints Using Base Excitation Testing
,”
Proceedings of International Modal Analysis Conference 2003 (IMAC-XXI)
,
Kissimmee, FL
, February 3–6.
10.
Boeswald
,
M.
, and
Link
,
M.
,
2004
, “
Identification of Non-Linear Joint Parameters by Using Frequency Response Residuals
,”
Proceedings of the 2004 International Conference on Noise and Vibration Engineering (ISMA2004)
, Leuven, Belgium, September 20–22, pp.
3121
3140
.
11.
Gaul
,
L.
, and
Lenz
,
J.
,
1997
, “
Nonlinear Dynamics of Structures Assembled by Bolted Joints
,”
Acta Mech.
,
125
(
1–4
), pp.
169
181
.10.1007/BF01177306
12.
Ibrahim
,
R. A.
, and
Pettit
,
C. L.
,
2003
, “
Uncertainties and Dynamic Problems of Bolted Joints and Other Fasteners
,”
J. Sound Vib.
,
279
(
3–5
), pp.
857
936
.10.1016/j.jsv.2003.11.064
13.
Schwingshackl
,
C. W.
, and
Petrov
,
E. P.
,
2012
, “
Modelling of Flange Joints for the Nonlinear Dynamic Analysis of Gas Turbine Engine Casings
,”
ASME J. Eng. Gas Turb. Power
,
134
(
12
), p.
122504
.10.1115/1.4007342
14.
Petrov
,
E. P.
, and
Ewins
D. J.
,
2004
, “
Generic Friction Models for Time-Domain Vibration Analysis of Bladed Disks
,”
ASME J. Turbomach.
,
126
(
1
), pp.
184
192
.10.1115/1.1644557
15.
Petrov
,
E. P.
, and
Ewins
,
D. J.
,
2003
, “
Analytical Formulation of Friction Interface Elements for Analysis of Nonlinear Multiharmonic Vibrations of Bladed Discs
,”
ASME J. Turbomach.
,
125
(
2
), pp.
364
371
.10.1115/1.1539868
16.
Petrov
,
E. P.
, and
Ewins
,
D. J.
,
2004
, “
State-of-the-Art Dynamic Analysis for Nonlinear Gas Turbine Structures
,”
Proc. IMechE G J. Aerosp. Eng.
,
218
(G
3
), pp.
199
211
.10.1243/0954410041872906
17.
Petrov
,
E.
,
2011
, “
A High-Accuracy Model Reduction for Analysis of Nonlinear Vibrations in Structures With Contact Interfaces
,”
ASME J. Eng. Gas Turb. Power
,
133
, p.
102503
.10.1115/1.4002810
18.
Schwingshackl
,
C. W.
,
Petrov
,
E. P.
, and
Ewins
D. J.
,
2012
, “
Measured and Estimated Friction Interface Parameters in a Nonlinear Dynamic Analysis
,”
Mech. Syst. Signal Process.
,
28
, pp.
574
584
.10.1016/j.ymssp.2011.10.005
19.
Kerschen
,
G.
,
Worden
,
K.
,
Vakakis
,
A. F.
, and
Golinval
,
J. C.
,
2006
, “
Past, Present and Future of Nonlinear System Identification in Structural Dynamics
,”
Mech. Syst. Signal Process.
,
20
(
3
), pp.
505
592
.10.1016/j.ymssp.2005.04.008
20.
Matek
,
W.
,
Muhs
,
D.
,
Wittel
,
H.
, and
Becker
,
M.
,
1994
,
Rolloff/Matek Maschinenelemente
13th ed.
,
Vieweg & Sohn
,
Braunschweig, Germany
.
21.
Oskouei
,
R. H.
,
Keikhosravy
,
M.
, and
Soutis
,
C.
,
2009
, “
Estimating Clamping Pressure Distribution and Stiffness in Aircraft Bolted Joints by Finite-Element Analysis
,”
Proc. IMechE G
,
223
(
7
), pp.
863
871
.10.1243/09544100JAERO596
22.
Kim
,
J.
,
Yoon
,
J.-C.
, and
Kang
,
B.-S.
,
2007
, “
Finite Element Analysis and Modeling of Structure With Bolted Joints
,”
Appl. Math. Model.
,
31
(
5
), pp.
895
911
.10.1016/j.apm.2006.03.020
23.
Williams
,
J. G.
,
Anley
,
R. E.
,
Nash
,
D. H.
, and
Gray
,
T. G F.
,
2009
, “
Analysis of Externally Loaded Bolted Joints: Analytical, Computational and Experimental Study
,”
Int. J. Press. Vessel. Piping
,
86
(
7
), pp.
420
427
.10.1016/j.ijpvp.2009.01.006
24.
Di Maio
,
D.
,
Berardi
,
S.
,
Vitale
,
N.
, and
Ewins
,
D. J.
,
2012
, “
Design of High Impedance Test Rig for Composite Structures Vibration Measurement
,” Proceedings of the 30th IMAC, A Conference on Structural Dynamics (
IMAC XXX
), Jacksonville, FL, January 30–February 2, pp. 453–463.10.1007/978-1-4614-2419-2_46
25.
Ewins
,
D. J.
,
2000
,
Modal Testing: Theory, Practice and Application
2nd ed.
,
Research Studies Press Ltd.
,
Baldock, England
.
26.
VDI Richtlininen,
2003
, VDI 2230 Blatt, 1, VDI Verlag GmbH, Düsseldorf, Germany.
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