Assign and Configure Load Histories

Use the Load Map tool to import/create multiple channels (load histories) which are then paired with static subcases to create the fatigue events.

All the available load types expand the options made available to you depending on the number of channels that need to be made available in the system for the fatigue calculation.

  1. From the Setup tools, click the Load Map tool.


    Figure 1.
    The Load Map dialog opens.
  2. Select a load type from the drop-down menu in the top, left of the dialog.
  3. Click in the top, right of the dialog to add a load case.
  4. Optional: Edit the maximum and minimum values for the desired loads.


    Figure 2.
  5. On the bottom half of the dialog, select a radio button option and click to create events.
    The fatigue subcases that are read from the result file can be paired with load histories either manually or automatically.

    Multiple pairs can be placed under a single event, and a sequential or superposition flag is assigned, default being superposition.

    Note: The number of time points should be the same if the pairs under the same event are superimposed.
    Option Description
    Manual Event Creation


    Figure 3.
    When Manual is selected and you click , an event is created without any load history and subcase pair assigned. You can drag and drop an equal number of load histories and subcases under an event.
    Note: The subcases should be dropped under an event first and then the load history channels.
    Auto Event Creation


    Figure 4.
    When Auto and Single Event are selected, before you click ,
    1. Select a subcase and a load history channel, or
    2. Select multiple load histories and subcase pairs that have an equal number of time points.

    Only one event is created when you click .



    Figure 5.
    When Auto and Multiple Events are selected, before you click ,
    1. Select multiple load histories and subcase pairs.

      The load histories must have an equal number of time points.

    2. Total number of events created = Number of channels selected / Number of subcases selected.
  6. Adjust the load magnitude, scale, offset, repeats, max gate range, and configuration of the events/subcases.
    Tip: Apply the magnitudes from a particular event or subcase to all the events/subcases created by right-clicking on a value and selecting Apply value to all events.
  7. Activate the check boxes of the events to be considered in the evaluation.


    Figure 6.
  8. Exit the dialog.
Tip:
  • Click to view a plot of the load.
  • Select an event, subcase, or loadcase and click to delete it.

Add a Time Data Load

  1. From the Load Map dialog, select Time Data as the load type.
  2. Click and browse for a file.
    Accepted file formats are: .rpc/.rsp, .csv, and .dac
  3. Click to add the load case.


    Figure 7.

Add a Constant Amplitude Load

  1. From the Load Map dialog, select Constant Amplitude as the load type.
  2. Click to add the load case.


    Figure 8.

Add a Block Load

Create a block series of various amplitudes. Each block can have "n" number of cycles.
  1. From the Load Map dialog, select Block Loading as the load type.
  2. Click .
    The Block Load dialog opens.
  3. Specify a name for the block load.
  4. Create blocks by entering a value in the No of Blocks field and clicking .
  5. Edit the values for Max Amplitude, Min Amplitude, and Cycles.
    Different blocks come together to make a block sequence, which is used for the damage calculation.
  6. Click Create Block Load.


    Figure 9.
Tip:
  • Select a block and click to delete it.
  • To exclude a block from the load, deactivate its check box.

Add a Transient Response Load

Transient subcases are supported for SN (uniaxial, multiaxial) and EN (uniaxial, multiaxial) fatigue calculations
  1. From the Load Map dialog, select Transient Response as the load type.
    Note: Load history input is not required for this case. For event creation, only time steps and repeats are needed.
  2. Select a subcase from the Subcase panel then click on the bottom half of the dialog to create an event.
    Stresses from each time step of the subcase are superimposed.

    Damage is calculated on the superimposed stress.