Apply Local Fatigue Solution Settings
Apply fatigue solution settings to a group of parts in the assembly.
 In the Project Tree for the fatigue subcase, rightclick Solution settings and choose Edit.

Click New.
A new group appears in the group list.

In the modeling window, select one or more parts/spot
welds for the group.
Tip: You can also select parts/spot welds from the Project Tree.
 Optional: You can choose Exclude all to exclude all parts/spot welds in the assembly.
 Optional: You can select the Include all seam welds check box to include all seam welds in the assembly.

Under the General tab in the dialog, choose from the following options:
Option Procedure Fatigue Method The following methods are available:  Uniaxial
 Multiaxial
SN Model Settings  Stress Combination
 The following stress combination models are available only
under uniaxial fatigue method:
 Critical plane
 Absolute max principal
 Maximum principal
 Signed von Mises
 Signed max shear
 Von Mises (random fatigue only)
 Mean Stress Correction
 The following mean stress corrections are available only
under uniaxial fatigue method:
 Goodman
 Gerber
 Gerber 2
 Soderberg
 FKM
 Tension Damage Model
 The following tension damage models are available:
 Goodman
 FKM  mean stress sensitivity input is required
 Shear Damage Model
 The Findley model is available for shear damage model under multiaxial fatigue method only. Findley constant and shear fatigue strength coefficient are required.
EN Model Settings  Stress Combination
 The following stress combinations are available only under
uniaxial fatigue method:
 Critical plane
 Absolute max principal
 Maximum principal
 Signed von Mises
 Signed max shear
 Tension Damage Model
 The following tension damage models are available:
 Smith, Watson, and Topper
 Morrow
 Shear Damage Model

The following shear damage models are available only under multiaxial fatigue method:
 FatemiSocie
 BrownMiller
Random Fatigue Model Settings  Damage Model
 The following damage models are available:
 Derlik
 Lalanne
 Narrow
 Steinberg 3band
 Parameters to Adjust Probability Density Function
 The following parameters are available:
 Upper stress range factor/upper stress range (MPa)
 Number of bins/stress range width
Endurance limit modifying factors  Select Surface condition.
The following options are available: polish, ground, machine, hotroll, forge.
 Select surface treatment.
The following options are available: Nitrided, shotpeen, coldroll.
 Select fatigue strength reduction factor.
Number of planes Enter the number of critical planes. 
Under the Spot weld tab in the dialog, choose from the following options:
Option Procedure Model method The following methods are available:  Rupp
 Modified Rupp
Mean stress correction FKM model is available. Mean stress sensitivity input is required.
Thickness correction Thickness effect consideration. Thickness reference and thickness reference exponent inputs are required.
TREF is used to define the reference thickness for thickness effect consideration. If the thickness of a shell (T) is greater than the specified value (TREF), the thickness effect is included by increasing the stress ( ${\sigma}_{ij}$ ) when thickness correction is applied:(1) $${\sigma}_{\mathit{ij}}={\sigma}_{\mathit{ij}}{\left(\frac{T}{\mathit{TREF}}\right)}^{\mathit{TREF}\_N}$$Default thickness reference = 25mm
Default reference exponent = 0.2
Endurance limit modifying factors Certainty of survival. Enter a value based on the scatter of the SN curve.
Default = 0.5
Number of angles Specify the number of angles to examine on sheet and nugget. Default = 20

Under the Seam weld tab in the dialog, choose from the following options:
Option Procedure Model method Volvo fatigue analysis method is available. This method calculates the bending and membrane stresses by using stress linearization approach at specific data points at the weld toe.
The number of data points are determined by the weld length. Damage is linearly interpolated between these points.
Stress combination The following options are available:  Normal
 Critical plane
 Absolute max principle
Mean stress correction FKM model is available. Mean stress sensitivity input is required.
Bending ratio threshold Specify the threshold for bending ratio. If the calculated bending ratio is higher than the threshold, an SN curve that is interpolated between membrane stresslife SN curve and bending stresslife SN curve is used. Seam weld membrane stresslife SN curve is used if the calculated value is lower than the threshold.
Default = 0.5
Maximum weld depth Specify the maximum weld depth. The specified value sets the maximum depth for which stress linearization through the thickness of the connected part from the weld toe is performed.
Default = 5mm
Thickness correction Thickness effect consideration. Thickness reference and thickness reference exponent inputs are required.
TREF is used to define the reference thickness for thickness effect consideration. If the thickness of a shell (T) is greater than the specified value (TREF), the thickness effect is included by increasing the stress ( ${\sigma}_{ij}$ ) when thickness correction is applied:(2) $${\sigma}_{\mathit{ij}}={\sigma}_{\mathit{ij}}{\left(\frac{T}{\mathit{TREF}}\right)}^{\mathit{TREF}\_N}$$Default thickness reference = 25mm
Default reference exponent = 0.2
Endurance limit modifying factors Certainty of survival. Enter a value based on the scatter of the SN curve.
Default = 0.5
 Click OK.