Creating the stress versus time and strain versus time data objects

The first step in creating the stress-strain curve is to create the stress versus time and the strain versus time data objects from the history output. The data objects will contain data from only the first step of the analysis, where the punch rests on the surface of the foam block and compresses the block under its own weight.

  1. In the Results Tree, double-click the XYData container.

    The Create XY Data dialog box appears.

  2. In this dialog box, select ODB history output if it is not already selected and click Continue.

    The History Output dialog box appears.

  3. In the History Output dialog box, do the following:

    1. Click the Variables tab.
    2. Filter the data according to *LE22*.
    3. In the Output Variables field, select Logarithmic strain components: LE22 at Element 1 Int Point 1 in ELSET CENT.
    4. Click the Steps/Frames tab.
    5. Select Step 1.
    6. Click Save As.

      The Save XY Data As dialog box appears.

    7. Name the X–Y data Strain, and click OK.

    A data object called Strain containing logarithmic strain data (LE22) from integration point 1 of element 1 during the first step of the analysis appears in the XYData container.

  4. Use a similar technique to create a data object containing stress data (S22) from integration point 1 of element 1 during the first step of the analysis. Name this data object Stress.

    Tip: Filter the variable list according to *S22*.

    Now you are ready to combine the two data objects to create a stress versus strain data object.

  5. Dismiss the History Output dialog box.