Importing a Set of Experimental Test Data

You can import experimental test data into the app, select a subset of the data for calibration, specify the deformation mode represented by the data, and describe each of the quantities.

When you import test data, you specify whether it represents tests in the time domain or in the frequency domain.

The app supports import from Excel spreadsheets (.xls*), text files (.txt), or comma-separated value files (.csv).

This task shows you how to:

See Also
Test Data Import Overview
Time Domain Deformation Modes and Test Data

Import Test Data in the Time Domain

You can import a test data set with data in the time domain.

Before you begin: You must have Microsoft Excel 2007 or later installed to import test data from an Excel spreadsheet.
  1. From the Calibration Tools section of the action bar, click Test Data .
  2. From the file selection dialog box that appears, do the following:
    1. Filter either for Excel files (*.xls;*.xlsx) or Text files (*.txt;*.csv).
    2. Select the test data file that you want to import, then click Open.
    The Material Test Data Import dialog box appears with your data displayed in a table.
  3. Optional: Enter a descriptive Name.
  4. From the Domain options, select Time.
  5. Specify the type of Deformation mode represented by this experimental test data. For test data in the time domain, you can specify the deformation mode as Uniaxial, Biaxial, Planar, Simple shear data, or Volumetric data.
  6. If you imported data from a text file or a comma-separated values file, specify the types of Delimiters used between data entries.

    For example, you should select Space if your data entries are separated by spaces; otherwise, two numbers separated by only a space will be interpreted incorrectly as a single number. Any delimiters you select that do not appear in the file are ignored.

    You can also select Treat Consecutive Delimiters As One to handle cases where multiple delimiters, such as spaces and commas, are present between data entries. For most situations the best option is to set all the available delimiters and to treat consecutive delimiters as a single delimiter.

  7. From the data table, highlight the data you want to import. You can click-drag on a subset of the data or highlight the rows and columns that you want to include.
  8. Click Next.
    A plot of your test data appears in the panel, with the quantities and units describing the data in the lower half.
  9. From the column headings above the tabular data, specify the correct data type and units for each column of data you want to import.

    For example, your selections for hyperelastic data might be Time (s), Nominal Strain (%), and Nominal Stress (Pa). You can select primary responses for some columns and secondary responses for others, and you can select Ignore from the column headings if you do not want to import a column of highlighted data.

  10. Click Next.
    A page appears with time, temperature, and orientation options, along with calibration notes.
  11. Optional: If you did not specify Time as one of the columns in your test data, specify the Strain rate, Total time, or Time interval for the data.
  12. Optional: Specify the Temperature value for the test data.
  13. Optional: If you plan to use the test data for an orthotropic or anisotropic material model, select Apply orientation to orient your test specimen relative to the material directions. In addition, select In-plane rotation angle if the specimen’s orientation can be specified by a single rotation angle; otherwise, select Specify directions to orient the specimen in a general 3D space.
  14. Optional: In the Notes box, specify any other testing information.
  15. Click Import.
    The import of the test data is completed and the panel remains open for import of other data.
  16. Click Close when done importing test data to close the panel.

The app imports your test data and plots the data.

Import Test Data in the Frequency Domain

You can import a test data set with data in the frequency domain to calibrate test data sets such as Dynamic Mechanical Analysis (DMA) data.

Before you begin: You must have Microsoft Excel 2007 or later installed to import test data from an Excel spreadsheet.
  1. From the Calibration Tools section of the action bar, click Test Data .
  2. From the file selection dialog box that appears, do the following:
    1. Filter either for Excel files (*.xls;*.xlsx) or Text files (*.txt;*.csv).
    2. Select the test data file that you want to import, then click Open.
    The Material Test Data Import dialog box appears with your data displayed in a table.
  3. Optional: Enter a descriptive Name.
  4. From the Domain options, select Frequency.
  5. From the Deformation mode options, specify the type of deformation represented by this experimental test data.
    OptionDescription
    Uniaxial The app assumes that the storage and loss modulus data is given in terms of Young's modulus, E s ( ω ) , E l ( ω ) .
    Torsional The app assumes that the storage and loss modulus data is given in terms of the shear modulus, G s ( ω ) , G l ( ω ) .
  6. If you imported data from a text file or a comma-separated values file, specify the types of Delimiters used between data entries.

    For example, you should select Space if your data entries are separated by spaces; otherwise, two numbers separated by only a space will be interpreted incorrectly as a single number. Any delimiters you select that do not appear in the file are ignored.

    You can also select Treat Consecutive Delimiters As One to handle cases where multiple delimiters, such as spaces and commas, are present between data entries. For most situations the best option is to set all the available delimiters and to treat consecutive delimiters as a single delimiter.

  7. From the data table, highlight the data you want to import. You can click-drag on a subset of the data or highlight the rows and columns that you want to include.
  8. Click Next.
    A plot of your test data appears in the panel, with the quantities and units describing the data in the lower half.
  9. From the column headings above the tabular data, specify the correct data type and units for each column of data you want to import. For example, your selections for DMA data might be Frequency (Hz), Storage Modulus (Pa), and Loss (Pa). You can select Ignore from the column headings if you do not want to import a column of highlighted data.
  10. Click Next.
    A page appears with temperature options, along with conversion parameters and calibration notes.
  11. Optional: Specify the Temperature for the testing and provide any other testing information in the Notes.
  12. Optional: Expand the Conversion parameters section and specify any of the following parameters to fine-tune the imported frequency domain data.
    OptionDescription
    Initial load rate The rate at which the specimen is loaded up to the mean strain. The default value is 0.1 strain/second.
    Initial hold time The amount of time to hold the initial mean strain before starting harmonic excitation.

    A larger initial hold time produces more excitation. By default, the initial hold is 10 times longer than the period of the first frequency to be simulated.
    Inter-frequency time The time or relative time (depending on whether you select Use relative inter-frequency timing) over which to ramp from one frequency’s mean strain to the next. The default value is 1.0.
    Use relative inter-frequency timing If selected, the interfrequency time is a fraction of the preceding frequency’s period. This option is selected by default.
    Sort frequencies Prompts the time history to run through the frequencies in order from the greatest to smallest.

    This approach causes the app to simulate frequencies with short periods when the total time value is small, which can help reduce the impact of floating-point arithmetic. This option is selected by default.
    Cycles per frequency The number of cycles to run for each frequency.

    The app calculates the storage and loss moduli from the final part of the final cycle. This number is usually sufficient to yield the steady-state stress response by the final half of the final cycle, which the app uses to calculate the storage and loss moduli. This parameter has a significant impact on performance. The default value is 2.
    Increments per cycle The number of increments taken in each cycle.

    Using a multiple of 4 ensures that the app imposes the minimum and maximum strain values for each cycle. A larger number of increments yields a more accurate stress history. This parameter has a significant impact on performance. The default value is 20.
    Increments for initial load The number of increments during application of initial mean strain. The default value is 10.
    Increments for initial hold The number of increments for holding the initial mean strain constant. The default value is 10.
    Increments between Frequencies The number of increments between each frequency’s cycling over which the mean strain is ramped between values. The default value is 10.
  13. Click Import.
    The app completes the import of the test data and leaves the panel open for import of other data sets.
  14. Click Close when done importing test data to close the panel.

The app imports your test data and plots the data.