PSI - Issue 57

Laurent Dastugue et al. / Procedia Structural Integrity 57 (2024) 355–364 Michael Klein et. al./ Structural Integrity Procedia 00 (2019) 000 – 000

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Fig. 2. Classic three step process.

The first step of the process is the classic FEA (Fig. 3). The FEA calculates the stresses at nodes. These results are temporarily stored on hard disks. For data reduction, often only the stresses on the component’s surfaces are written out. Then stress gradients normal to the surface can no longer be accurately calculated. Nevertheless, a large amount of data must be cached on disk and its handling organized. This includes copying the data to where it is needed for the next step. The industrial example has 41 stress states which were required for the fatigue analysis. The stresses of three additional assembly steps necessary for the correct simulation are not saved on disk.

Fig. 3. Process step 1, stress analysis.

The second step of the process is the fatigue analysis to get the damage (Fig. 4). Many fatigue life analyses must be carried out. For each of every load level a separate fatigue analysis is needed. Each single fatigue analysis run reads all stress result files to combine them at different load level, and to calculate the damage related to the load level. For the industrial example in the second step, 70 fatigue life analysis are performed with different load levels. To do this, all 41 stress result files must be read and processed 70 times. In addition, the model file must be read for each fatigue analysis.