Transient Fatigue Analysis with .RSP file input

Transient Fatigue Analysis with .RSP file input

             1. Hypergraph set up


Import the .RSP file containing the road load data into Hypergraph.


 Choose the requested data and click on Plot to visualize the curves.



Export the curves into TABLEG format and save them in a single .dat file.

In the.dat file.

! In every TableG definition erase the second LINEAR word or an error will occur during the run.

(This step is under development and will be fixed in the next version of Hypergraph)


Make sure that the IDS of the TABLEG entries are unique to the model. If not, then they must be manually changed.


The correct format will look like this:




2. Import the .dat file with the INCLUDE command into the .fem file.


Optistruct Command

Make sure that the .dat and .fem file are in the same folder or enter the full path ‘…/…/…/tableg.dat’ of the file.

              The same can be achieved in Hypermesh via import.

              Click on File> Import > Solver Deck >Select the .dat file to include.


In solver and import options > click on “Import file as an include” to include the curves on a separate input and not in the main model> Import behavior = preserve > Import


In Include panel we can review the included TABLEG curves.




3. Transient Analysis Setup


Create TLOAD1 cards referencing the excitation load in the Exciteid field and its corresponding road load curve (TABLEG) in TID field. Select a type of loading from LOAD, DISP, VEL, ACCEL.



All the TLOADs created can be added together with a respected scale factor in a DLOAD card.                                                                                                                                     


Create the transient loadstep


          4. Fatigue analysis Set up.

    Create the fatigue load map using the results from the transient analysis.

With FATDEF card we reference the elements that we want to perform the fatigue analysis and connect them with their fatigue properties (PFAT card).

With FATPARM card we define the fatigue analysis parameters.

With MATFAT material card, which is an extension of MAT1 card, we input the material’s fatigue data.

Create the Fatigue loadstep.




  1. Fatigue Results are stored in the .h3d file and they can be reviewed in Hyperview


Click on measure>Static MinMax Result to review the minimum and maximum contour value and their locations.


Damage Contour


Life Contour