Stress Life approach for the seam weld fatigue is an extension of the regulation-based fatigue evaluation using the
HyperLife Weld Certification workflow.
Random Response Fatigue is evaluated at each global direction for each weld
location.
The implementation process is shown in Figure 1.
(1)
= Total damage from 1, 2, and 3 in each direction.
= Total exposure time ().
= Fatigue Life (maximum number of cycles of
a particular stress amplitude 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:
Supports only OptiStruct model/results.
Supports only shell element evaluation (via element stress).
Report is only available on requesting Rainflow output via
Preferences.
Stress Query is supported only for Nominal Approach.
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.
Location Parameters
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.
Output
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.