IEC

Random Response Fatigue is evaluated at each global direction for each weld location.

The implementation process is shown in Figure 1.

(1)

D_{d i r e c t i o n} = \sum \frac{n}{N}

$D_{d i r e c t i o n} = \sum \frac{n}{N}$

$D_{d i r e c t i o n}$ $D_{d i r e c t i o n}$ = Total damage from 1 $σ$ $σ$ , 2 $σ$ $σ$ , and 3 $σ$ $σ$ in each direction.
$n$ $n$ = Total exposure time ( $n_{_{σ}}$ $n_{_{σ}}$ ).
$N$ $N$ = Fatigue Life (maximum number of cycles of a particular stress amplitude $σ$ $σ$ for the material prior to failure) from the Material SN curve.

Fatigue Material: SN materials for Weld locations in the Points context are created/selected from the Material context.; To assign materials to parts, right-click the material in the My Material tab and select Add to Assign Material List from the context menu. From the Points context, select the appropriate weldline and enable the Evaluate checkbox. In the Location section, select the appropriate material in the Material - Transverse column. Once the selection is made, right-click the material and select Apply current value to all Locations from the context menu.; Both Slope-intcept,1-seg and Slope-intcept,2-seg are supported.; Weld Templates are supported for Material assignment to weld locations.
Query Report: Preferences > Save Rainflow Data can be used to query elements for viewing Report.

Restriction:

Evaluation Distance Parameters

Parameter	Description
Evaluation Distance	Reference distance to find the evaluation location from the weld element at which the stress values are extracted. See Find Evaluation Positions for more information. Restriction: Only Nominal Evaluation method is supported for IEC.
Weld Width	Width of the weld material from the web wall. This parameter is ignored if the evaluation distance is specified manually.

Refer to Materials for material creation and its assignment.

Note: In the following parameters, X can be any evaluation location from 1-10.

Parameter	Description
Material - Transverse	SN curve considered for the calculation of Fatigue Life in XX.
Material - Longitudinal	SN curve considered for the calculation of Fatigue Life in YY.
Material - Shear	SN curve considered for the calculation of Fatigue Life in ZZ.

Cumulative Damage in XX, YY, and ZZ across all events and total across all three directions per location.
Master_1D_Damage, maximum of the total damage from all locations.
Results per location:
- Computed RMS stress per direction for all events.
- Damage per direction for all events.
- Total exposure time $n_{1}_{σ}$ $n_{1}_{σ}$ for all events.
- Fatigue Life/cycles for 1 $σ$ $σ$ for all events.