Proposed F.D.& E. Periodic Overload Test Data File Format

Send discussion & questions to John Bonnen. jbonnen(a)ford*com In fatigue situations where small and large amplitude cycles are intermixed, the fatigue curve in the long life region is usually lowered by up to 50% depending upon material. Tests data sets are now being created to quantitatively define this effect. The tests data does not fit into the normal SAE fatigue test data format. The following is and example of a proposed file format to store and transfer periodic overload test data results.


# Proposed Fatigue Design & Evaluation Comm. Standard Periodic Overload Test 
# data file Format.
#
#FileType= strain_life_overload    #overload strain  life type standard file
#DataType= raw              #"raw"= measured, as opposed to "fitted"
#
#  Copyright (C) 2000 J.J.F.Bonnen
# This data file is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the license, or (at 
# your option) any later version. 
#  This data file is distributed in the hope that it will be useful, but 
# WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTA- 
# BILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public 
# License for more details. 
#  You should have received a copy of the GNU General PUblic License along 
# with this program; if not, write to the Free Software Foundation, Inc., 
# 59 Temple Place -Suite 330, Boston, MA 02111-1307, USA. Try also their 
# web site: http://www.gnu.org/copyleft/gpl.html 
# 
# Any line that begins with a # sign is a comment line, or an identifier
#line.   Blank lines can also be inserted anywhere.
#------------------------
# Certain lines that begin with a #SYMBOL= VALUE     have special meanings
# that can be decoded by the receiving program, e.g.:
# 
#NAME= SAE1045
#NAME= Periodic_Overload_Tests 
#UNITS= KSI
#Su= 102.
#Sy= 57.
#E=  29500.
#%RA= 48.
#BHN= 203
 
# SAE Phase 2, steel, J.J.F.Bonnen PhD Thesis, U.of Waterloo
# 0.47%C 0.80Mn .016P .016S .22si .08Cu .04Ni .05Cr <.005V
# <.005Al <.005Ti .036Cb <0.005Ta <0.005Pb <0.0005B
# Rb=91.5 ,  Upper/Lower Yield points on monotonic
#------------------------
# other comments can be anything in ASCII text
#Normalized SAE 1045, Pearlite + ferrite, 25micron grain size
# pearlite/ferrite banding along rolling direction
#
# Here is an example of a data point set. Note that a comment field
#can also be appended to the data field, or in between the data lines.
#A data line is assumed to be any line that is not a blank or a comment
#line.  The data should contain one fatigue test per line, and on each
#line the fields are seperated by one or more blanks.
#
# SC = Small CYcle
# OL = OverLoad Cycle
# CA = Constant Amplitude
# e = strain
# S = stress
#    SC   SC Fail     SC      SC     SC     SC      SC        OL     CA OL  OL     OL    OL
#Total e  Blocks     per      S    Mean    Mean  Plastic     Total   Life    S    Mean  Plastic initial
#  Amp              block    Amp     e      S      e Amp     e Amp.  (Nf)   Amp    S    e Amp   modulus
0.0007    6238.0    20000   20.4  0.00380  34.6  0.0000400  0.00450   12476  55.0  0.0  0.00265 28603
0.00075   4347.7    10000   20.9  0.00387  35.4  0.0000625  0.00462   11500  56.3  0.0  0.00270 28020
0.0008    5928.2     1000   22.6  0.00395  34.9  0.0000625  0.00475   10600  57.5  0.0  0.00280 29492
0.0008    5155.0     5000   22.0  0.00382  34.3  0.0000500  0.00462   11500  56.3  0.0  0.00270 28593
0.00082   3664.0     1000   21.9  0.00393  35.6  0.0000500  0.00475   10600  57.5  0.0  0.00280 29500
0.0009    3270.0      500   24.2  0.00385  33.3  0.0000625  0.00475   10600  57.5  0.0  0.00280 29229
0.001     1977.0      500   26.6  0.00375  30.9  0.0000500  0.00475   10600  57.5  0.0  0.00280 28937
0.00125   1201.0      250   -0.0  0.00525  -0.0  0.0001200  0.00650    4985  64.5  0.0  0.00390 29500
0.00125   1116.0      250   30.2  0.00350  27.3  0.0001200  0.00475   10600  57.5  0.0  0.00280 30219
0.0015    1967.0      100   34.7  0.00000  -1.3  0.0002200  0.00550    6710  59.5  0.0  0.00325 29761
0.00167   1437.4      100   35.4  0.00308  22.1  0.0002000  0.00475   10600  57.5  0.0  0.00280 29500
0.002     1001.0      100   38.3  0.00275  19.3  0.0004800  0.00475   10600  57.5  0.0  0.00280 28471
0.002     1354.1      100   40.7  0.00000  -9.2  0.0005250  0.00475   10600  57.5  0.0  0.00280 30080
0.00235   1640.3       50   40.7  0.00240  16.8  0.0007500  0.00475   10600  57.5  0.0  0.00280 29500
#
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