FKM

Version: 6^th Edition 2012

List of Classification Parameters

1st Evaluation Distance: Reference distance value for the 1st evaluation location from the weld element at which the stress values are extracted.
2nd Evaluation Distance: Reference distance value for the 2nd evaluation location from the weld element at which the stress values are extracted.
Weld Width: Width of the weld material from the web wall. This parameter is ignored if specifying the evaluation distance is done manually.
Note: Refer to - Find Evaluation Positions.
Material Type: Parameter to specify the material of shells. Options: steel, al.
Notch Class - Transverse Location_X: Notch class definition considered for the fatigue limit calculation for the normal stress component in the transverse direction (perpendicular to the axis of the weld) at ‘X’.
Note: Where ‘X’ can be any evaluation location.
Notch Class - Longitudinal Location_X:: Notch class definition considered for the fatigue limit calculation for the normal stress component in the longitudinal direction (parallel to the axis of the weld) at ‘X’.
Notch Class - Shear Location_X: Notch class definition considered for the shear stress component at ‘X’.
Material Yield - Location_X: Material yield value used for the static evaluation.
Residual Stress factor (KEnormal): Residual stress factor used for calculations for the normal components of stress.
Residual Stress factor (KEtau): Residual stress factor used for calculations for the shear components of stress.
Mean Stress sensitivity (Mnormal): Mean stress sensitivity factor used for calculations for the normal components of stress.
Mean Stress sensitivity (Mtau): Mean stress sensitivity factor used for calculations for the shear components of stress.
Overload Situation: Parameter to decide overload situation. Options: F1, F2, F3, F4. Based on the selection, the fatigue limit calculation formula may vary.
Reference Number of Cycles (Nc): Reference number of cycles for welded components.
Number of Cycles at Knee point - Normal (Ndnormal): Number of cycles at knee point of normal component constant amplitude S-N curves.
Number of Cycles at Knee point - Shear (Ndtau): Number of cycles at knee point of shear component constant amplitude S-N curves.
If Edge - Layer solidification: Possible options are yes or no.
Slope Exponent – Normal: Slope exponent for the normal component of constant amplitude S-N curves.
Slope Exponent – Shear: Slope exponent for the shear component of constant amplitude S-N curves.
If Material GJL: Parameter used to indicate GJL behavior.
Material GJL factor (Knle): Constant allowing for the non-linear elastic stress-strain behavior of GJL.
Exponent N for thickness
Thickness Factor
Temperature Factor (Ktd)
Solidification Factor (Kv)
Plastic Support (npl)
Weld Line Factor (aw)
Softening Factor (Pwez)
Material Safety Factor (jF)
Load Safety Factor (jS)

Static Assessment

The following process is followed for Static assessment:

Collect the max. absolute Stresses in transverse and shear component ( $σ_{x}; τ$ $σ_{x}; τ$ ) across all assigned loadcases.
Calculate Equivalent Static Stress ( $σ_{V W}$ $σ_{V W}$ ) with transverse and shear component.
Retrieve the material yield (Rp) value from the Points context.
Calculate Static Strength ( $σ_{S K, W}$ $σ_{S K, W}$ )
$σ_{S K, W} = R p * α_{w} * n_{p l} * ρ_{W E Z}$ $σ_{S K, W} = R p * α_{w} * n_{p l} * ρ_{W E Z}$
- $a_{w}$ $a_{w}$ = Weld Factor
- $n_{p l}$ $n_{p l}$ = Plastic support factor
- $ρ_{W E Z}$ $ρ_{W E Z}$ = Softening factor
Calculate static utilization ( $a_{S K}$ $a_{S K}$ )
$a_{S K} = \frac{σ_{V W}}{σ_{S K, W} / γ_{S t a t}}$ $a_{S K} = \frac{σ_{V W}}{σ_{S K, W} / γ_{S t a t}}$
- $γ_{S t a t}$ $γ_{S t a t}$ = Static Safety factor