Abstract

Fatigue life predictions are conducted for a high temperature composite for hypersonic vehicle structural applications. A SCS-6/Timetal® 21S [0/90]s composite is evaluated under thermomechanical fatigue (TMF) as well as under typical hypersonic mission profiles and segments of those missions. The fatigue life analysis is based on micromechanical stresses which, in turn, are input into a damage summation model. Spectrum loading is decomposed into a series of in-phase and out-of-phase TMF segments whose lives are predicted from a life fraction model which was developed for isothermal and TMF data. Analytical predictions for the mission spectrum and the simple mission profiles are compared with experimental data obtained here as well as in a previous study. The model is demonstrated to be able to predict fatigue life under mission spectrum loading based solely on calibration under simple isothermal fatigue and TMF conditions.

References

1.
Life Prediction Methodology for Titanium Matrix Composites
, ASTM STP 1253,
W. S.
Johnson
,
J. M.
Larsen
and
B. N.
Cox
, Eds.,
American Society for Testing and Materials
,
West Conshohocken, PA
,
1996
.
2.
Johnson
,
W. S.
,
Mirdamadi
,
M.
, and
Bakuckas
,
J. G.
, Jr.
, “
Damage Accumulation in Titanium Matrix Composites Under Generic Hypersonic Vehicle Flight Simulation and Sustained Loads
,”
Thermo-Mechanical Fatigue Behavior of Materials
, ASTM STP 1263,
M. J.
Verrilli
and
M. G.
Castelli
, Eds.,
American Society for Testing and Materials
,
West Conshohocken, PA
,
1996
, pp.
252
-
265
.
3.
Mirdamadi
,
M.
and
Johnson
,
W. S.
, “
Fatigue of [0/90]2S SCS-6/Ti-15-3 Composite Under Generic Hypersonic Vehicle Flight Simulation
,”
FATIGUE 93
, Volume
II
,
J.-P.
Bailon
and
J. I.
Dickson
, Eds.,
EMAS
,
1993
, pp.
951
-
956
.
4.
Mirdamadi
,
M.
,
Bakuckas
,
J. G.
, and
Johnson
,
W. S.
, “
Mechanisms of Strain Accumulation in Titanium Matrix Composites at Elevated Temperatures
,”
Mechanics of Composite Materials—Nonlinear Effects
, AMD-Vol.
159
,
American Society of Mechanical Engineers
,
New York
,
1993
, pp.
245
-
252
.
5.
Nicholas
,
T.
and
Johnson
,
D. A.
, “
Time- and Cycle-Dependent Aspects of Thermal and Mechanical Fatigue in a Titanium Matrix Composite
,”
Thermo-Mechanical Fatigue Behavior of Materials
, ASTM STP 1263,
M. J.
Verrilli
and
M. G.
Castelli
, Eds.,
American Society for Testing and Materials
,
West Conshohocken, PA
,
1996
, pp.
331
-
351
.
6.
Nicholas
,
T.
, “
Fatigue Life Prediction in Titanium Matrix Composites
,”
Journal of Engineering Materials and Technology
 0094-4289, Vol.
117
,
1995
, pp.
440
-
447
.
7.
Neu
,
R. W.
and
Nicholas
,
T.
, “
Methodologies for Predicting the Thermomechanical Fatigue Life of Unidirectional Metal Matrix Composites
,”
Advances in Fatigue Lifetime Predictive Techniques: 3rd Volume
, ASTM STP 1292,
M. R.
Mitchell
and
R. W.
Landgraf
, Eds.,
American Society for Testing and Materials
,
West Conshohocken, PA
,
1996
, pp.
1
-
23
.
8.
Hartman
,
G. A.
and
Russ
,
S. M.
, “
Techniques for Mechanical and Thermal Testing of Ti3Al/SCS-6 Metal Matrix Composites
,”
Metal Matrix Composites: Testing, Analysis and Failure Modes
,
ASTM STP 1032
,
W. S.
Johnson
, Ed.,
American Society for Testing and Materials
,
West Conshohocken, PA
,
1989
, pp.
43
-
53
.
9.
Hartman
,
G. A.
and
Buchanan
,
D. J.
, “
Methodologies for Thermal and Mechanical Testing of TMC Materials
,” submitted for publication in
Characterization of Fiber Reinforced Titanium Matrix Composites
,
AGARD Structures and Materials Panel
,
France
,
09
1993
.
10.
Hartman
,
G. A.
and
Ashbaugh
,
N. E.
, “
A Fracture Mechanics Test Automation System for a Basic Research Laboratory
,”
Applications of Automation Technology to Fatigue and Fracture Testing
, ASTM STP 1092,
A. A.
Braun
,
N. E.
Ashbaugh
, and
F. M.
Smith
, Eds.,
American Society for Testing and Materials
,
West Conshohocken, PA
,
1990
, pp.
95
-
110
.
11.
Mirdamadi
,
M.
and
Johnson
,
W. S.
, “
Modeling and Life Predictions for TMC's Subjected to Mission Profiles
,”
Life Prediction Methodology for Titanium Matrix Composites
, ASTM STP 1253,
W. S.
Johnson
,
J. M.
Larsen
and
B. N.
Cox
, Eds.,
American Society for Testing and Materials
,
West Conshohocken, PA
,
1996
, pp.
573
-
594
.
12.
Nicholas
,
T.
, “
An Approach to Fatigue Life Modeling in Titanium Matrix Composites
,”
Materials Scientific Engineering
,
A200
,
1995
, pp.
29
-
37
.
13.
Russ
,
S. M.
,
Nicholas
,
T.
,
Bates
,
M.
, and
Mall
,
S.
, “
Thermomechanical Fatigue of SCS-6/Ti-24Al-11Nb Metal Matrix Composite
,”
Failure Mechanisms in High Temperature Composite Materials
, AD-Vol.
22
/AMD-Vol.
122
,
G. K.
Haritos
,
G.
Newaz
, and
S.
Mall
, Eds.,
American Society of Mechanical Engineers
,
New York
,
1991
, pp.
37
-
43
.
14.
Nicholas
,
T.
,
Russ
,
S. M.
,
Neu
,
R. W.
, and
Schehl
,
N.
, “
Life Prediction of a [0/90] Metal Matrix Composite Under Isothermal and Thermomechanical Fatigue
,”
Life Prediction Methodology for Titanium Matrix Composites
, ASTM STP 1253,
W. S.
Johnson
,
J. M.
Larsen
and
B. N.
Cox
, Eds.,
American Society for Testing and Materials
,
West Conshohocken, PA
,
1996
, pp.
595
-
617
.
15.
Neu
,
R. W.
,
Coker
,
D.
, and
Nicholas
,
T.
, “
Cyclic Behavior of Unidirectional and Cross-Ply Titanium Matrix Composites
,”
International Journal of Plasticity
, Vol.
12
,
1996
, pp.
361
-
385
.
16.
Nicholas
,
T.
and
Russ
,
S. M.
, “
Fatigue Life Modeling in Titanium Matrix Composites
,”
Proceedings of the American Society for Composites: Ninth Technical Conference
,
Technomic
,
Lancaster, PA
,
1994
, pp.
940
-
947
.
17.
Neu
,
R. W.
and
Scott
,
D. T.
, “
Effects of Temperature and Frequency on the TMF Mechanisms in Cross-ply Titanium Matrix Composites
,”
Proceedings of the American Society for Composites, 11th Technical Conference
,
W. S.
Johnson
, Ed.,
Technomic
,
1996
, pp.
359
-
368
.
18.
Coker
,
D.
,
Ashbaugh
,
N. E.
, and
Nicholas
,
T.
, “
Analysis of the Thermomechanical Fatigue Behavior of [0] and [0/90] SCS-6/TIMETAL®21S Composites
,”
Thermomechanical Behavior of Advanced Structural Materials
, AD-Vol.
34
, AMD-Vol.
173
,
W. F.
Jones
, Ed.,
American Society of Mechanical Engineers
,
New York
,
1993
, pp.
1
-
16
.
This content is only available via PDF.
You do not currently have access to this content.