Work with FinLiv v. N

1
Work with FinLiv v. N

• Jan Papuga

The development of FinLiv application was
realized thanks to the support of TACR agency
2
Current state

• 2 application versions currently
• FinLiv v. N
• released February 2014 developed mostly by Jan
  Papuga
• S-N curves recording, viewing, regression
  analysis (Basquin model, model according to
  Kohout-Vechet)
• integrates the basis of static experiments data
  manipulation storing, viewing through
  interface, saving
• FinLivX
• a modification of FinLivK (released 30. 6. 2013)
• prepared by Jakub Hasman as a post-processing of
  his bachelor thesis
• implements the functionality related to inclusion
  of static experiments their record, viewing,
  analyses based on CSN standard
• Expected inclusion of e-N curves prepared by a
  PhD student at the VŠB-TUO university

3
What is FinLiv

• An application intended to save experimental data
• Fatigue experiments
• Both S-N and e-N curves
• No crack growth currently
• Static experiments under development
• Built in Visual Basic for Applications with a
  common MS Excel interface
• An intended pre-processor for managing data later
  saved to on-line FinLiv database

4
FinLiv file content

• form sheet the basic graphical interface
  enabling the input of data
• data sheets any other sheets with description
  of test group sets

User can pick the selected test group
5
Test group vs. curve
Test group

• Set of all experiments realized with one batch of
  material
• Treatment relates to the preparation of
  semi-product related to all individual curves

Exception ID_REF relates to every individual
curve, because the sources providing the data can
differ during more extensive experimental
campaigns
Curve

• Related to a particular test group
• Treatment relates to any thermo-mechanical
  operation encountered during preparing the
  specimens

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Thermomechanical treatment
Hint shown while mouse hovers over the cell
describing the meaning of the parameter
Parameters to be filled in potentially are marked
by salmon colour

• Two times within one form
• operations during preparing semi-product
• operations while preparing the final specimen
• Defined
• type of the operation
• environment during the treating
• possible commentaries for whatever not included
• variables

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Specimen

• Approx. 20 different pre-configured specimen
  designs
• SP_V1 SP_V12
• based on the configuration, thenumber of
  geometric parametersand their meaning differ
• Related to every curve, can differwithin one
  test group
• SP_ORIENT describes the orientationof the
  specimen axis to the majordimensions of the
  semi-product

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Description of input loading
The same colour convention valid for inputs
This view relates to fatigue experiments
Hints included to describe the meaning

• Up to 4 load channels can act simultaneously

• Load modes
• tension
• plane bending
• rotating bending
• pressurizing
• torsion
• thermal load

• Load types
• harmonic loading
• constant loading
• triangular
• trapezoidal
• sampled load input
• general load
• load blocks
• Gauss load

well done
to be finalized
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Description of input loading
The same colour convention valid for inputs
This view relates to static experiments
Hints included to describe the meaning

• Up to 2 load channels can act simultaneously

• Load modes
• tension
• compression
• torsion
• plane bending

• Load types
• 0-max
• constant loading

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Master and Slave load channels
ta
sa 1.682?ta ft10 ?fb
N

• Master parameter is that one taken as a reference
  for this kind of loading (and used for graphic
  output therefore)
• Other parameters of the loading (on the same
  channel or on other channels) are either its
  multiples or constants

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Master and Slave load channels II
ta
sa 1.682?ta ft10 ?fb
N

• In version M, an additive constant can be added
  to the end of formula
• a curve with lower stress being constant C
  100
• note
• only the additive constant can be added () or
  subtracted (-). No other operations are allowed
• allowed operators x multiple, addition, -
  subtracting
• multiple should precede any further operation
  it is the marker that the input is a formula and
  not a constant value
• only one multiple and one addition or subtracting
  allowed in one formula

sa sh/2-C/2
LD_V1 x0.5-50
sm sh/2C/2
LD_V2 x0.550
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Individual test data input

• END parameter for S-N curve
• describes the condition of the end of the
  experiment
• two lifetimes can be recorded
• for the final break of the specimen
• for the END
• Unfinished experiments marked by I symbol in the
  appropriate column

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Action buttons - Save

• Process the data either in data sheets or in the
  form
• Save
• transfers the current setup (both test group
  information and curve information currently
  depicted) in the form sheet to the appropriate
  data sheet
• !!!doesnt saves the file!!!

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Action buttons - Show

• Starts a form to select the curves of a given
  test group to be send to a separate file for a
  regression analysis
• Access to another test group than currently
  selected enabled by clicking the three dots
• The backslash \ shows that the content is a
  test group and not a curve
• The final file created is described in this
  presentation later on

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Action buttons Back Up

• A similar selector tool as by Save, but only test
  groups listed
• Any selected test group is detected and saved as
  a separate csv file
• The range of saved data is based on
• the number of cells continuously non-empty on the
  line CURVE_ID
• the number of continuously non-empty cells in the
  column B of the appropriate data sheet

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Action buttons Import

• Pushing this buttonresults in this message box
• A file has to be selected then based on the
  previous choice
• Any .csv file previously saved or prepared to
  work as the data sheet
• A sheet named csv in the selected Excel file

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Action buttons Remove

• Allows the user to remove a selected test group
  while keeping the data sheet links OK
• Removing the data sheet manually by the Excel
  functions causes, that the MARK listbox (C3 cell
  in form) will not reflect it and the application
  can break down when this item is asked
• Can be solved today by closing the FinLiv
  application and opening it again

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Action buttons APDL Specimen

• Information about specimens used for selected
  curves is processed
• a text file is generated
• it serves as an input for ANSYS APDL macro
• based on this inputthat macrocreates the
  FE-modelof the specimen, itsboundary
  conditionsand runs the analysis

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Action buttons Input for PragTic

• An extensive form for automated defining of the
  analysis in PragTic fatigue solver is opened
• Functionality of this command is described later
  on

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Working with FinLiv

• The data can be input through form but also
  directly into the data sheets
• Be careful there is no identity between the
  number of your choice in a selected listbox and
  the number in appropriate cell of the data sheet
• sometimes it is identical, sometimes not
• it takes some time before you grasp the right ID
  codes of the mostly used items
• test and check first by using the form

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Data sheets

• Each curve of a particular test group is recorded
  to a separate column
• A header related to all curves ends by TREAT4
  line
• The exceptional ID_REF record is placed to the
  line 3
• It is expected that most of the records could be
  placed to another line, there is no defined order
• Exception Records of Px_MARK, Dx_y, Ix_y and
  D_COMMENTx should be placed consecutively,
  without any interruption

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Naming conventions

• The name of the data set should correspond to
  abbreviation of the surnames of the team members
• Hudson, C. M. A study of fatigue and fracture
  in 7075-T6 aluminum alloy in vacuum and air
  environments . Technical report NASA-TN-D-7262,
  L-8829 . Washington, 1973
• Results in the test set Hud
• 1 author only
• no previous similar record
• three letters optimum
• Grover, H. J. Bishop, S. M. Jackson, L. R.
  Fatigue strengths of aircraft materials
  axial-load fatigue tests on notched sheet
  specimens of 24S-T3 and 75S-T6 aluminum alloys
  and of SAE 4130 steel with a stress-concentration
  factors of 2.0 and 4.0. Technical report
  NACA-TN-2389. Washington, NACA 1951.
• Results in the test set GBA, GBB, GBC
• more authors, but also more materials used
• three letters optimum
• first letters of the first two authors used, an
  alphabet marker added on the 3rd position

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Numbering rules S-N curves

• The experiments on smooth unnotched specimens
  should be numbered within IDs 01-39, if possible
• Special curves
• fully reversed axial loading ID30
• repeated axial loading ID31
• fully reversed torsion ID32
• (repeated torsion ID33) preferable, but not
  strictly required
• Experiments on other notched geometries set to
  next decades, e.g.
• specimen with a hole through (40reversed
  push-pull, 41repeated tension, 42reversed
  torsion, 43-49 other combinations)
• specimen with a circumferential U-notch
  (50reversed push-pull, 51repeated tension,
  52reversed torsion, 53-59 other combinations)

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Numbering rules S-N curves II

• Also the mode of axial loading matters say e.g.
  the most of experiments is done while combining
  tension and torsion, but also combinations of
  torsion with plane bending occur
• 01-29, 33-39 any more complex experiments
  covering tension and or torsion
• 30-32 basic uniaxial load modes for tension and
  torsion
• 40-41 plane bending experiments
• 42 torsion (can be related to a different
  specimen type then 32)
• 43-49 any combination of plane bending and/or
  torsion on this specimen type

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Numbering rules Static data

• In order to quickly orient in the data sheet a
  prefix S is added to any static tests, while
  being reported in form sheet
• The datasheet doesnt include this prefix and you
  can recognize the static curve by CUR_TYPE3
• Special IDs
• averaged tension 30
• averaged compression 31
• averaged torsion 32
• averaged bending 33

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Static data averaged vs. experimental

• Static tests are usually done on more samples
  (3-5), but only the average values are mostly
  used
• Experimental curves
• those with complete experimental data (force vs.
  displacement)
• will be evaluated after Show (not ready in this
  version)
• averaged curve will be completed in SumUP
• a link between the experimental curve and the
  averaged curve will be saved to csv
• Averaged curves
• do not contain any experimental data, just the
  statistics of the regression analysis
• have unique IDs (see the previous slide)
• a link between them and all experimental curves
  used for their deriving will be saved to csv

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Input of static data

• Mostly the same dialogues, but load modes, load
  types and end of the tests differ
• Other description of the datapoint it relates
  to one time instant of the static test
• Substantially more time instants can be recorded
  than 60
• Parameter ROWS allows to change the dimension of
  the record (limited only by the number of rows in
  Excel)
• ROWS is hard set in fatigue curves processing to
  60

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New items

• New test group
• item new in the MARK listbox of the form
• asks for a name of the test group, from which the
  content is inherited (curves can be then removed
  manually in the data sheet)
• import of an existing csv file
• copying an existing sheet to a new location and
  renaming it
• copying the csv file from another file
• New curve
• item new in the CURVE_ID listbox of the form
• copying some existing record to appropriate
  column of the data sheet the CURVE_ID listbox
  is updated, when another test group is selected
  and then the right one chosen again

Push the button in the form
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Show procedure
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Show procedure

• For selected curves of a selected test group
  creates a file in the same directory
• the file is named TestGroupName.xls, where the
  TestGroupName is replaced by the test group
  abbreviation
• data of each curve is placed into a separate
  sheet named TestGroupNameCurve
• Two additional sheets are created
• SumUP covers results of all separate regression
  analyses done for individual curves
• csv contains the original data sheet itself
• The operation can be repeated additively, i.e. a
  part of curves can be processed first, then
  another one, etc.

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Curve sheet
Parameters of regressions
Experimental data points
Buttons for starting the regression analyses
Regression curve according to Basquin formula
Graph for visual interpretation
Regression curve according to Kohout-Vechet
formula
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Initial state after Show operation

• Only experimental data and related points in the
  graph are shown

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Running S-N curve button
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and check the SumUP sheet

• Contains
• functional buttons
• Write to csv writes the regression parameters to
  the csv sheet (can be then imported to FinLiv via
  Import button)
• Dummy Model prepares input for Dummy model
  application (APDL script for pre-processing
  multiaxial fatigue limit experiments in ANSYS)
• description of regression parameters
• proposal on credibility coefficients
• master curve description
• Here shown only S-N curve data
• Below that also the same output for Kohout-Vechet
  model (K-V) is provided

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Running KV curve button
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KV regression

• More complex
• necessitates the use of Solver add-on to Excel (a
  non-linear solver utility)
• check its existence in your MS Excel before
  running it
• Run the initial estimate procedure?
• a query box asking if to run the initial estimate
  or continue from the last saved estimated
  parameters
• useful when the regression analysis collapses

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KV regression collapse

1. Run the analysis from the initial estimate on the
   set of data points omitting the outward-lying
   points
2. If succeeded include all data points, deny to
   use the initial estimate and run the analysis
   from the last saved regression parameters
3. If failed go to item 1 and repeat it again with
   another set of data points