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-SAE Fatigue Design and Evaluation Committee Meeting Micro
Minutes March 30, March 31 & April 1, 1998 Kansas State Universi-
ty - Manhattan, KS Host: Kevin Lease
Disclaimer: These are not the official minutes. They are
just one individual's notes
Dates and the location of the next meeting: October 19, 20 & 21,
1998 in Minneapolis MN. Kelly Donaldson of MTS Systems Corp will
host the meeting.
Monday, March 30, 1998
Digital Prototype Structural Durability Task Group Meeting: Raj
Thacker Chairperson: The efforts of this task group will be do-
cumented in the full minutes that will be issued later this sum-
mer.
Tuesday, March 31, 1998
Main Committee Meeting: Tom Cordes called the meeting to order.
Tom discussed the Annual Standards Development Participation Fee,
and indicated that discussions were underway to eliminate the
fee. But for now, unless your fee is paid, you will be dropped
from the mailing list, and you will not received the meeting an-
nouncements directly from SAE.
Each of the Division Chairmen reviewed their agenda.
John Hakula Structural Analysis
Chin-Chan Chu Fatigue Life Predication
Raj Thakkar Component Testing
Dan Morrow Road Load Data
Ed Lu Materials Property
Jack Champaigne Surface Enhancement
Russ Chernenkoff reported that they had a good session at the SAE
Congress. There were 10 papers and Tim Topper was the keynote
speaker. In addition, Russ indicated that a book is available,
PT67, on the best papers over the last 9 years.
Tom Cordes reported that AE14++ on multi-axial fatigue is moving
forward. There will be 16 papers, 6 are done and in hand, 4 are
in the mail, and 6 more need to be returned by 1 June 1998.
Ralph Stevens reported that the 27th Annual SAE Short Course on
Fatigue would be held July 28-31, 1998. It will be held in Troy,
MI.
Henry Fuchs Student Travel Award Presentation: The winner of this
meeting's Henry Fuchs travel award was Radovan Rolovich, Ph.D.,
University of Tulsa. The title of his presentation was "A New In-
cremental Plasticity Model and An Energy Based Critical Plane
Damage Parameter".
Materials Property Division: Ed Lu chaired the Division Meeting.
The minutes from the October meeting were approved. The follow-
ing presentations were made:
HCF Fatigue Behavior for the Three Different P/M Materials
for Both Smooth and Notched Specimens with Correlation to
the Threshold Fatigue Crack Growth Behavior
- Nate Stephens discussed briefly how samples were made
and the advantages of the process. The same materials
that were used in the previous study will be
used in this work. Some monotonic, LCF, and da/dN curves
will be used, but these samples will be tested in the high
cycle area.
Composites Task Group Progress Report - Alan Kallmeyer and
Greg Finnes: Variables that will be investigated for the
glass mat thermo plastic were listed. Some of these are
frequency effects, thermal effects, and R ratios.
Testing is in progress.
Digitizing Material Property Data - Chin Chan Chu: A proposal
was made on what should be included in a database, and how
it might be used.
Various Methods to Determine the Standard Fatigue Constants
- Ali Fatemi and Matt Roessle: A comparison was made with
three materials and three different methods to determine
the cyclic fatigue parameters. With the three methods,
some of the parameters are similar, and others were quite
different.
Fatigue Life Prediction Division: Chin Chan Chu chaired the Divi-
sion Meeting. The minutes from the March meeting were approved.
The following presentations were made:
An Overview of the State of the Art of Multi-Axial Fatigue
by Darrell Socie: Some of the models work well and others
not so well. Cyclic stress-strain model - works well.
Damage Model - some better than others. Cyclic counting
- some questions i.e., how to count shear? Damage accumula-
tion
- sequence effects can count a lot and does not work well.
Notch Analysis- a question.
The Role of Fretting in Fatigue Damage - The Navy's Experience
by Gary Smith, U S Navy: This was a case history of a tail
rotor failure. In the analysis and initial testing, the ef-
fects
of fretting were omitted. As a result of the failure, these
were included in a second analysis and test, and these result-
ed
in a much better life prediction.
Component Testing Division: Raj Thakkar chaired the Division
Meeting. The minutes from the March meeting were approved. The
following presentations were made:
Digital Prototype for Durability Task Group Activity Update:
Each
of the individuals that are doing work provided an overview on
the
past six months and what was discussed in the task group meet-
ing on
Monday. Several senior projects were in progress, the ATV is
being digitized, and analysis is underway. A rig test is
forthcoming.
Darrell Socie discussed where the ATV fits into SAE FD&E and
how it
is a natural progression. He pointed out that in 1975 the
Keyhole
Program was started. It was a 1-D problem, and some problems
were
worked out. In 1985, the SAE Shaft program started. This was
a 2-D
problem, and much harder to analyze. A lot of tests and
analysis,
and validation went into that. The ATV is a 3-D problem and
the ATV
is a cost-effective vehicle for addressing the 3-D process.
Further Analysis on the SAE Weld Fatigue Project (British Weld
Approach) by Jim Robertson: The British Welding Standard ap-
proach
and the predictions obtained for the current SAE weld study
were
reviewed. An analysis of a G weld also was reviewe The labd
tests to simulate field conditions were run fully reversed at
70 Hz, and the British Standard predicted very close to the
actual life.
Fatigue Sensitive Characterization of Surface Roughness by Art
Cogan Kansas State: Art is currently working with 4130 steel,
1
polished surface, and 4 other roughness levels. He has gen-
erated
fatigue data, and analyzed some surface profiles. Next, he
will
analyze the surface with Fourier analysis.
A CAD Based Design Process for Fatigue Analysis by K.K. Choi
- University of Iowa: He presented the basic process of how
you go from a model, perform the dynamic analysis, and the
life analysis. The process is in place to take a Pro/E model
and get the life of the component. He showed the analysis
of a lower control arm.
Road Load Data Acquisition Division: Dan Morrow chaired the Divi-
sion Meeting. The minutes from the March meeting were approved.
The following task group efforts were discussed:
Rainflow Format Standard - Mark Pompetzki: Some comments:
should use bins not engineering units, should include = cycles,
should include hanging and standing cycles.
Time History Standard - A. Whelan: Some comments were
presented. Currently two formats RPCIII, and DAC. Are commonly
used and a new standard should accommodate both.
Statistics/Analysis of Multipass Road Load Data - C. Leser: Not
much since last meeting. Statistical Modeling of Rainflow Histo-
grams by Jason Roth, U of Illinois: Jason is working on taking
one user data and extrapolating it to many users. Modeling by a
statistical density method using a kernel approach. Tested model
on 19 sets of data, but model should be tested on more data.
On Virtual Proving Grounds - VPG by Arthur Tang ETA: Working with
software to simulate the way vehicles are tested in real time.
These software packages can use full vehicles or components.
Software can predict loads, stresses, fatigue life, noise, vibra-
tion, and etc.
On Vehicle Performance Simulation by Allan Belfield: Presented a
video of simulated vehicle running over bumps, etc. Comparisons
between actual and predicted results have been good, but non-
linear codes should predict better.
Structural Analysis Division: John Hakula chaired the Division
Meeting. The minutes from the March meeting were approved. The
following presentations were made:
ATV Component Analysis by Dan Klann - John Deere: The ATV vehi-
cle, the frame, and the first model of the frame from the Univer-
sity of Illinois were reviewed. Generally, a lot more work needs
to be done and possible future work was reviewed.
MIG Weld Analysis by C. Sieck - Caterpillar: Charlie presented a
method to predict residual stresses in several types of welds.
Both single pass and multi pass welds.
Weld Standard Applications and Stress Intensity Factors for Weld-
ments by G. Glinka: Six standards were reviewed: German to US.
Often little science was involved. Some codes include allowance
for fatigue limit and some do not, Most use some form of linear
damage. Generally, the codes conclude that failures are the
result of crack growth and that small cycles cause some damage.
A Universal Stress Intensity Solution was presented.
Surface Enhancement Division: Jack Champaign chaired the Division
Meeting. The minutes from the March meeting were approved.
Status reports were made on five standards. Topics discussed
were:
J443 Procedure for Using Standard Shot Peening Test
Strip, D. Francis J2277 Shot Peening Coverage, D. Francis J442
Almen Strip, Holder and Gage, D. Francis Subcommittee Reports and
Discussion J442 Almen Strip, Holder and Gage, A. Ahmad J2441 Shot
Peening, D. Hale AMS-MIL-S-13165 Shot Peening of Metals, now
available
from SAE AMS 2431/1/2 to be revised to include S390 shot size
and reconciles chemistry to industry practice
Wednesday March 12, 1997
Technical Session: The following presentations were made.
A CAD-Based Design Process for Fatigue Analysis, Reliability
Analysis and Design Optimization By K.K. Choi, Center for Comput-
er Aided Design, The University of Iowa: This was partly a con-
tinuation of yesterdays presentation. Generally, the process to
get a result was discussed, and how to use the model to optimize
a design was described. Modifications to the model could be made
to better handle the ATV.
Fatigue Crack Growth Behavior of Induction Hardened Shafts under
the Effect of Residual and Bending Stress by Hong Yan Zhang,
Dept. of Mechanical Engineering, and The University of Iowa: An
analytical and experimental investigation of sub-surface fatigue
crack growth in round induction hardened pins was studied. The
effect of inclusions was discussed. The model developed predict-
ed the experimental results within about a factor of 1.5.
Airframe Development Process Overview by Ric Leist, Cessna Air-
craft: The general design process was discussed from the perfor-
mance parameters to the internal design and the required design
life. The philosophy of design that is used was discussed. In
these designs, a lot of flight-testing is performed.
Full Scale Damage Tolerance Testing - Improving Test Efficiency
using Truncation and Marker Loads By Peter Gould, Manager, Air-
craft Structural Integrity, Raytheon Aircraft Company: This type
of test is often performed after the frame is certified, and can
be used to establish inspection programs. The process to arrive
at a load spectrum was discussed. This included the summing of
segments and how the spectrum is often edited.
Airframe Fatigue Testing on the Citation X By Dan Kalal, Cessna
Aircraft: The full frame test of the Citation was described. The
test took about 6 months to setup, and ran 24 hours a day and was
up and running seventy to eighty percent of the time.
Service Life Evaluation and Life Extension Techniques by Johnny
Smith, Group Engineer, Durability and Damage Tolerance, Raytheon
Aircraft Company: Many of the older aircraft have reached their
original design lives. The steps used to work with a customer to
extend the life of the aircraft were discussed. These could in-
clude inspection programs, and repair guidelines.
Fatigue Analysis for Test Life Predictions by Ric Leist, Cessna
Aircraft: In the design and analysis process the first step is to
establish what the operational use parameters will be. The nor-
mal analysis steps that are taken, and the analysis of a failure
were discussed.
Divisional Planning Sessions were held concurrently in two rooms.
The future work efforts of these five Divisions will be coordi-
nated by the chairman and the task group leaders of the respec-
tive divisions. Please contact the chairman with any questions or
needs. Documentation of future work planned will be included in
the full minutes to be distributed before the next meeting.
Future Meeting Schedule:
October 19, 20 & 21, 1998: (at) Minneapolis, MN - Kelly Donaldson (MTS)
April 19, 20 &21, 1999: (at)Chrysler Technical Center, Detroit, MI Tony Barr (Chrysler)
Fall 1999: (at) Purdue University, Lafayette, IN - Jack Champaigne
Spring 2000: (at) Waterloo, IA - Ray Thompson
Fall 2000: (at) University of Toledo, Toledo, OH Ali Fatemi
Spring 2001: (at) Detroit, MI Russ Chernenkoff
Fall of 1999 or 2000 possible alternate location: North Dakota State, Fargo, ND
Respectfully submitted by: Phil Dindinger SAE FD&E Vice-Chairperson
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SAE Fatigue Design and Evaluation Committee Meeting Structural
Analysis Division Unconfirmed Minutes Kansas State University -
Manhattan, Kansas (March31 April 1, 1998)
Tuesday, March 31 Divisional Progress Meeting
MIG Weld Analysis - C. Sieck Weld analysis at Caterpillar is in-
volved with product and processes. They strive to optimize weld-
ing procedures to improve fatigue performance. They have spent
much time and money measuring residual stresses in plates with
fabricated grooves and at weld toes. Results have indicated some
changes in assumptions on residual stresses. Correlation work
goes on in real time to get curves to match, not just the end
points, including bend test plates to release residual stresses,
flat plates with holes to measure distortion after first welds,
and predictions of residual stresses to indicate gross stresses
and strains locked into the structure. They are interested in
through thickness effects, which can influence multipass weld se-
quences, and the effect of yield strength versus variability.
Typically they use Abaqus with a modified material model. They
are gaining insights from analysis of structures.
Fatigue Design Codes for Weldments - Greg Glinka Fatigue design
codes for weldments typical for bridge and crane structures were
developed in Britain around 1934, and during the 1970s and 80s in
the Euro Code, and BS5400 in 1980. These standards applied con-
ventional wisdom to use for the designs based on a majority of
opinions that certain methods were appropriate for use. Fatigue
strength is only a rough reference point. For example, S/N
curves for critical locations? You need to develop S/N curves
for any configuration of loads and geometry, or apply S/N curves
for similar details. For static loading they calculate stress at
the throat plane of a weld and then calculate principle stress
etc. For fatigue we look at peak stresses and match the stress
state of a critical position, but we use nominal stress calculat-
ed somewhere else. BS5400: What stress is used to generate the
S/N curve? Confused, then use stress in element you estimate is
going to crack. Pick weld category corresponding to:
B= smooth specimen Or, depending on corresponding
environments:
C=...
D=...
E=...
F=...
G=
Effective S/N curves in standards above 107 are based
on discussions and applications of fracture mechanics, generally
not test data. We should use hot spot stresses, in other words
element stresses extrapolated to surfaces, when there are multi-
ple S/N curves to pick from. European codes include fatigue lim-
its up to 108 cycles.
Stress Intensity Factors for an Arbitrary Elliptical Shaped Crack
- Greg Glinka
Fatigue cracks in welded, shotpeened and case hardened machine
components are subjected to various stress fields induced by the
load and residual stress. The method presented is based on the
generalized weight function technique enabling the stress inten-
sity factors to be calculated for planar cracks subjected to any
Mode I stress field. A numerical procedure for calculating
stress intensity factors for arbitrary non-linear stress distri-
butions is briefly discussed. The method is particularly suitable
for modeling fatigue crack growth of single buried elliptical and
multiple cracks. The important feature of the weight function is
that it depends only on the geometry of the cracked body. If the
weight function is known for a given cracked body, the stress in-
tensity factor due to any load system applied to the body can be
determined by using the same weight function. The success of the
weight function technique for calculating stress intensity fac-
tors lies in the possibility of using superposition.
A general weight function expression that can be used to approxi-
mate weight functions for a variety of geometrical crack confi-
gurations subjected to one-dimensional stress fields of Mode I is
in the form: m(x,a)= A general form for weight function
is proposed as:
KA=mA(x,y;P) =
Where P= force
Distance between force location and point of SIF
= Inverted external free boundary contour
= Inverted crack contour The stress intensity factor
due to a continuous stress field applied to the crack surface
is calculated by integrating the product of the weight function
and the stress field over the entire crack area. In the case of
numerical calculation the continuous stress field has to be re-
placed by a finite number of forces.
KA =
Note: Contact John Hakala for reference report.
Structural Analysis of ATV Components - Dan Klann This report
will be included with the Digital Prototype Structural Durability
Project
Wednesday, April 1 Divisional Planning Meeting
Possible ATV Modeling Projects:
Bushings - Chris Lessor
Tire Models - Alan Belfield
- Ric Mousseau
- K.K. Troi
ADAMS model - Zhengxian Bai
Shot Peening Model - Jin Qian/J. Green
Structural Test Models - Rick Munson
Respectfully Submitted by: John Hakala SAE FD&E Structural
Analysis Division Chairperson
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SAE Fatigue Design and Evaluation Committee Fatigue Life Predic-
tion Division Unconfirmed Minutes Kansas State University -
Manhattan, KS (March 31 - April 1, 1998)
Tuesday, March 31 Divisional Progress Meeting
1) The minutes from the October meeting in Ft. Mitchell, Kentucky
were approved as written. 2) Professor D. Socie of University of
Illinois gave an overview of:The State of the Art of Fatigue Life
Prediction Methods. Professor Socie reviewed the status of dif-
ferent aspects of the current method, which include constitutive
equations, notch stress analysis, rainflow counting methods, and
damage models. Overall we were given a C grade. 3) Gary Smith
gave a presentation showing problems in the fretting fatigue area
that the US Navy is facing and would like to get some help in
analyzing and solving. Wednesday, April 1 Divisional Planning
Meeting Crack Propagation: Reflecting on the morning session on
aerospace applications, C.C.Chu proposed an exploration of crack
growth analysis techniques. Dan Klann noted that the methodolo-
gies that are present in available programs do differ somewhat in
the details. Tom Cordes suggested using the weld sample chal-
lenge project data (See minutes from past several meetings). Ma-
terials data is available for the parent material (0.1 R ratio,
whole sigmoidal curve). The data can be downloaded from Tim Lan-
glaiss web site: (http://www.menet.umn.edu/~langlais/SAE-
fde/saehome.html) Tom Cordes offered the weld samples if anyone
wished to perform post failure metallurgical review. Multiaxial
Fatigue Data: Chin-Chan Chu suggested all available multiaxial
test data be collected and documented in order to make it avail-
able to committee members. She and Tim Langlais have data, with
some overlap. Tims is on his web site; Chus is available and do-
cumented but not accessible from outside Ford. They agreed to
communicate and come up with a common set of data. Data formats
were briefly discussed, and simple ASCII files were felt to pro-
vide the quickest, but maybe not most efficient, method.
Fretting Fatigue: There was no apparent interest in pursuing
fretting fatigue at this time.
Digitization of materials data: Chin offered her data and metho-
dology as a means to encourage others to evaluate her approach as
it translates into fatigue life predictions. Residual stress
analysis, relating to the Surface Enhancement proposed project:
It was suggested that the results from the shotpeened samples be
presented to the committee as normalized lives, similar to what
was done for the weld challenge project. The residual stress
profiles would be needed in order to do the life predictions.
Multiaxial Life Predictions: Should we initiate an evaluation of
techniques, as Darrell Socie had presented in his talk on Tues-
day? Would we aim to separate the effects of notch correction,
residual stresses and mean stresses? The issue of using avail-
able results versus a new series of tests was discussed. We
would need simple discriminating tests for the latter. It was
suggested that we start with the data in AE6 and AE14. Chu will
review these ideas and come up with a plan to be distributed by
email or at next meeting. Respectfully Submitted by: Chin-Chan
Chu SAE FD&E Fatigue Life Prediction Division Chairperson
-----------------------------------------------------------------
SAE Fatigue Design and Evaluation Committee Component Test Divi-
sion Unconfirmed Minutes Kansas State University - Manhattan, KS
(March 31 - April 1, 1998)
Tuesday, March 31 Divisional Progress Meeting
Raj Thakkar chaired the Division Meeting. The minutes from the
October 1997 meeting were approved. The activity champions of the
"Digital Prototype for Durability" renamed to "Digital Prototype
for Structural Durability" presented updates on their tasks. The
presenters were Dan Klann, Ali Fatemi, Darrell Socie, Christoph
Leser, Brian Dabell, Dan Morrow, and Andrew Whelan. For further
detail and future plans for these activities, please refer to the
minutes of the special meeting of the task group held on March
30.
Darrell Socie made a special presentation showing parallels
between the keyhole project (mid-1970s), the spindle project (mid
1980s-mid 1990s), and the current ATV project. He showed the na-
tural progression that has taken place between these projects.
The keyhole being a 1-D problem, the spindle as a 2-D problem,
and the ATV as a 3-D problem. He then brought attention to
achievements made during the first two efforts and the contribu-
tion made by the group to the field of fatigue analysis. There-
fore, he said that the group should not get hung up in defining
the exact behavior of the ATV. Instead we should look at the ATV
as a cost effective specimen on which to try our tools for 3-D
problem solving.
Lee Tucker mentioned that the Sundown Ski Resort near Dubuque,
Iowa (a place where ATVs have been seen in use, even to the point
of observing structural fatigue failures) can be used as a cost
effective ("free") proving ground (P.G.) for further study of
load histories and customer usage.
Arthur Cogan-graduate student working with Kevin Lease at Kansas
State University presented the status of his work on Fatigue Sen-
sitive Characterization of Surface Roughness. This was a con-
tinuation and the final presentation of his Masters Thesis on
this subject.
James Robertson from J. I. case made presentation on his work on
life prediction of the SAE weld fatigue samples. This was a
follow-up to the 97 October meetings discussion, in which a wide
range of predictions by numerous participants from both universi-
ties and industry were compared and evaluated. James summarized
his analyses, showing that BS-400 weld classes D, F, and G were
the closest cases to the SAE weld samples. He also discussed the
fatigue of weld samples at high frequency (70 Hz).
K. K. Choi from the University of Iowa center for CAD presented
"A CAD Based Design Process for Fatigue Analysis". The process
showed application of the approach on a sample problem dynamic
modeled in DADS, taken into Finite Element Modeling based stress
analysis, taken into fatigue life prediction.
Wednesday, April 1 Divisional Planning Meeting
Raj Thakkar chaired the meeting. The discussion centered around
the "Digital Prototype for Structural Durability", with emphasis
on activities planned to take place between this meeting and the
next meeting.
Ali Fatemi stated that the University of Toledo will com-
plete their projects in Modal Analysis of the vehicle frame,
ADAMS modeling of the vehicle suspension, correlation between
analyses and tests, and refinement of the model. There was also a
proposal to purchase an additional frame; however, when further
discussion in this meeting revealed uncertainty as to which ac-
tivities the frame will be used for, the group decided not make
the purchase for now.
Andrew Whelan at Tower Automotive will also perform modal
Testing. It was suggested that Modal Analysis be performed on (a)
the frame alone and (b) on the frame with engine attached. The
same configuration should also be used in dynamic correlation
studies. To help determine the approach and parameters for the
modal tests, Andrew will send out an e-mail requesting input to
the question: what is your use of the modal data? Another ques-
tion brought up by the group regarding modeling and correlation
was is the University of Illinois student project FE model, which
currently has emphasis for use in stress analysis. Is it also go-
ing to be used for modal analysis? Will it have the proper level
of detail for extracting structural mode shapes?
As a response to many open issues regarding the tasks and direc-
tion of this project, Charlie Sieck stated the need for an up-
front plan that addresses which components to study, how to han-
dle interconnections of components, which assumptions to make,
and how to validate them. Charlie and Raj will write up a plan
and circulate it throughout the group for feedback. The plan will
identify short term and long term tasks and objectives. It will
not change plans of the current student projects at both the
University of Toledo and the University of Illinois. Darrell So-
cie suggested that the Charlie/Raj plan should include ideas that
can become candidates for the 1998 fall semester student pro-
jects.
Respectfully Submitted by Raj Thakkar SAE FD&E Component Test
Division Chairperson
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SAE Fatigue Design and Evaluation Committee Road Load Data Divi-
sion Unconfirmed Minutes Kansas State University - Manhattan, KS
(March 31 - April 1, 1998)
Tuesday, March 31 - Divisional Progress Meeting
1. The minutes from the previous meeting were approved. 2. Mark
Pompetzki gave a status report on the Rainflow Format Standard.
3. Andrew Whelan gave a status report on the Time History Stan-
dard. 4. No report was given on multibody dynamics modeling pro-
ject. 5. Christoph Leser gave a status report on statistics
analysis of multipass load data. He mentioned three approaches
that are being used; rainflow histograms, exceedance plots, and
time histories. 6. Jason Roth, University of Illinois, gave a
presentation on Statistical Aspects of Load Histories. He uses
exceedance plots along with rainflow histograms in the analysis.
The analysis is used to predict load history results for a common
operating condition if the condition is allowed to happen in the
future. Also, for example, if 10 runs are available the 99 per-
cent load history can be predicted. 7. Arthur Tang, Engineering
Technology Associates, gave a presentation on Virtual Proving
Grounds. The presentation showed several examples of using com-
puter modeling to predict stresses in various components during
dynamic events. 8. Alan Belfield, ARUP, gave a presentation on
Vehicle Performance Simulation.
Wednesday, April 1 - Divisional Planning Meeting
Dan Morrow chaired the meeting. He announced that Christoph
Leser will be taking over the duties of chairperson as of fall
1998 and Ray Thompson will continue as Vice-Chairperson.
Rainflow standard - Mark Pompetzki lead a discussion about the
current format of the proposed standard for rainflow data. The
major uses for rainflow data are fatigue life predictions, recon-
struction of data, and manipulation of data. Mark would like to
see some enhancements to the format for manipulation purposes.
The enhancements include adding the bin numbers, including = cy-
cles, adding from-to counts and including multi-channels in the
file format. Mark will provide a sample of the proposed rainflow
format with enhancements to the committee for approval.
Time history format - Andrew Whelan lead a discussion about the
need for a common time history format for transferring data among
various users. Some of the formats discussed were nCodes DAC
files, MTSs RPCIII files, and Somats SIF files. Andrew will talk
to these companies, and possibly others, to get their input for a
proposed standard format for time history files.
Multi-body dynamics - Ric Mousseau was absent and no one else had
information about the status of this project.
Statistical analysis of data - Christoph Leser lead a discussion
about statistical analysis of multi-pass data. The ATV data that
was collected in the fall of 1996 is available for anyone to
analyze. It is located on a server at the University of Illinois
(joe.me.uiuc.edu/pub/download) which can be logged onto as
anonymous. Jason Roth will be documenting the details of this
data in his thesis. Jason is looking for other multi-pass data
that he could try his statistical analysis procedure on.
New Business - The road load division will be involved in the
load measurements of the ATV project. Dan Morrow has agreed to
lead that effort. Dan has asked that individuals submit a list
of channels that they believe should be measured on the ATV.
Respectfully submitted by: Ray Thompson SAE FD&E Road Load Data
Division Vice-Chairperson
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SAE Fatigue Design and Evaluation Committee Material Property
Division Unconfirmed Minutes Kansas State University - Manhattan,
KS (March 31 - April 1, 1998)
Tuesday, March 31 - Divisional Progress Meeting
1. The minutes from the October meeting in Ft. Mitchell,
Kentucky were approved as written. The new Chairperson, Ed Lu,
was introduced.
2. Status of Current Activities
- Powder Metal - Nate Stephens reviewed the LCF fatigue
behavior for three different P/M materials for both smooth and
notched specimens. The results will be correlated to the thres-
hold fatigue crack growth behavior. In addition, the high cycle
fatigue behavior of the powder metals will be investigated.
- Composites Task Group Progress Report - Greg Finnes re-
viewed the studies of the frequency effects on the fatigue of the
thermoplastic composites. The objectives are to determine the
general fatigue characteristics and explore the
temperature/frequency effects. Test results and future research
plan were presented.
3. Presentations
- Digitizing Material Property Data - Chin Chan Chu (Attach-
ment #1)
- Various Methods to Determine Fatigue Properties - Matt
Roessle/Ali Fatemi (Attachment #2)
Wednesday, April 1 - Divisional Planning Meeting 1. Current
Activities
- Composite Materials Group - Greg and Alan will continue
the work on the frequency, temperature, and stress amplitude ef-
fects on the fatigue strength of thermoplastic composites. Ed Lu
will contact Mohamad El-Zein to schedule a task overview at the
next meeting.
- Powder Metal Group - Nate will investigate the high cycle
fatigue behavior of the metals with three different processes.
Ralph Stephens will contact Tom Prucher of Burgess-Norton for fu-
ture project redirection.
2. New Business
- Shot Peening Coverage - Jack Champaign proposed a study
on the effect of coverage/intensity on fatigue strength. Russ
Chernenkoff, Phil Dindinger, Jack Champaign, and Ed Lu will iden-
tify resources and propose a plan for this project. Russ Cher-
nenkoff will give an overview on the effect of the shot peening
on fatigue strength at the next meeting.
- AISI Material Properties Development - Ali Fatemi will continue
the effort and try to see if the new J2409 data format can be
adopted. - - ATV Materials - Russ Chernenkoff and Ralph
Stephens will try to determine the material being used for the
control arm and the frame.
Ref: Attachment #1
"Digitization of Material Fatigue Properties" -- Presentation by
Chin-Chan Chu, 3/31/98, Manhattan, Kansas
Fatigue Properties required for structural durability analysis:
-- The Cyclic Stress-Strain Relationship, and
-- The Damage Parameter vs. Fatigue Life Curve
Why is digitization being proposed?
-- Current fitting method difficult: the 4 constants in the
Coffin-Manson equation and the 2 constants in the power law
stress-plastic strain equation are interrelated, which makes sa-
tisfactory fitting for both the strain- life and the stress-
strain data set very difficult.
-- If these are intrinsic material properties, they should be
determined by experimental results, which may or may not be well
represented by the aforementioned two equations.
What do we do then?
-- Collect all constant amplitude proportional test data.
-- Select a damage parameter, expressible in terms of measured
stress and strain quantities.
-- Search either numerically or analytically for the plane on
which the damage parameter reaches its maximum.
-- Plot the aforementioned maximum damage parameter against
observed fatigue life.
-- A potentially good damage parameter can be identified when
>90% of the data points can be included in a factor of 2 band
formed by a best-fit curve.
Using SAE1045 data published in AE14 as examples, results for
four damage parameters versus fatigue life plots were shown.
(Figures 7, 8, 9, 10)
The fitted curve is then digitized. The stress-strain plot from
uniaxial tests is also fitted. The digitized properties have
been submitted to be published in the upcoming AE14+ edition of
the Multaixal Fatigue book.
Attachment #2 follows Attachment #1
Respectfully submitted by: Ed Lu SAE FD&E Material Property
Division Chairperson
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SAE Fatigue Design and Evaluation Committee Surface Enhancement
Division Unconfirmed Minutes Kansas State University - Manhattan,
KS (March 31 - April 1, 1998)
Attendees: 3/31/98
Jack Champaigne - Electronics Inc. Dennis Scharer - Ervin Amasteel
Chris Norton - Barnsteel Abrasive George Raderm - Barnsteel Abrasive
Don Coovert - Pellets Inc. David Hale - Ervin Amasteel
Benny Johnson - Wheelabrator Abrasive Jim McFarlane - Panabrasive
David Francis - Metal Improvement Paul Trotta - Hope Supply Inc.
1. Confirmation of Minutes - Ft. Mitchell Kentucky
Paul Trotta requested two statements regarding Almen strips,
(J442), be added to the minutes from the Ft. Mitchell meeting.
No motion was made. Trottas comments and study on Almen Strips
will be added to this meetings minutes as attachments. 2.
Chairpersons Report. Chairperson Champaigne reported on the fol-
lowing topics. The $350.00 annual membership fee is being recon-
sidered by the executive committee. Reported that shot peening
will be applied to a component of the ATV vehicle that all of the
other Divisions of the full committee are currently working on. A
request to participate in the second day of these committee meet-
ing was made by the chair. This participation would encourage
participation in our committee from users, which participate in
other committees, within our division. NOTE: The next meeting
will be held in Minneapolis, MN on October 19, 20 and 21, 1998.
3. Status Reports
? SAE J443 Procedure for Using Standard Shot Peening Test Strip -
D. Francis. J-443 was not balloted since the last meeting. Dave
Francis will send to SAE staff to be mailed out for ballot
? SAE J2277 Shot Peening Coverage - D. Francis. The task force
did not complete required review of changes in the document from
the Ft. Mitchell meeting. The task force will review the docu-
ment and it will be sent out for review by the whole committee
before the next meeting.
? J-442 Test Strip, Holder and Gage for Shot Peening - J. Cham-
paigne. J-442 was balloted and there was a lack of responses.
During the meeting additional ballots were submitted, indicating
the document was approved. 4. Subcommittee Reports and Discus-
sion
J-442 - Test Strip, Holder and Gage for Shot Peening - J. Cham-
paigne. Jack Champaigne review a testing design that A. Ahmad
will be completing. Test strips from five different sources will
be included in the work. General Electric and Metal Improvement
will be peening the strips for this project. The time frame for
completion is still unknown. The group is waiting for strips from
Japan and China. Paul Trotta handed out a study he conducted on
three different manufactured strips. Attached to these minutes
is a copy of that study, including two comments in reference to
discussion from the Ft. Mitchell meeting. ? J2441 Shot Peening -
D. Hale. Line by line review of this document was completed in
the meeting. Dave Hale will revise and circulate for comments
before the next meeting.
5. New Business No discussion. 6. Announcements: Jack Cham-
paigne made the following announcements. ? AMS-MIL-S-13165 Shot
Peening of Metals is now available from SAE ? AMS 2431 /1 and /2
to be revised to included S390 shot.
7. Adjournment: Chairperson Champaigne adjourned the meeting.
Respectfully submitted by: Dennis Scharer for the SAE FD&E Sur-
face Enhancement Division.
Note: Please contact Jack Champaigne or Dennis Scharer for the
attachments referenced. They were not submitted for distribution
with the minutes.
The: SAE Fatigue Design and Evaluation Committee Special Meeting
Digital Prototype for Structural Durability March 30, 1998-1:00
to 5:00 P.M. Minutes were sent with the conventional paper mail
because they were very dependent on the attachments which were
not all available in electronic format.
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