FKM

Version: 6th 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:
  1. Collect the max. absolute Stresses in transverse and shear component ( σ x ;τ MathType@MTEF@5@5@+= feaahqart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaaeaaaaaaaaa8 qacqaHdpWCpaWaaSbaaSqaa8qacaWG4baapaqabaGcpeGaai4oaiab es8a0baa@3BCB@ ) across all assigned loadcases.
  2. Calculate Equivalent Static Stress ( σ VW MathType@MTEF@5@5@+= feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVCI8FfYJH8YrFfeuY=Hhbbf9v8qqaqFr0xc9pk0xbb a9q8WqFfeaY=biLkVcLq=JHqpepeea0=as0Fb9pgeaYRXxe9vr0=vr 0=vqpWqaaeaabiGaciaacaqabeaadaqaaqaaaOqaaabaaaaaaaaape Gaae4Wd8aadaWgaaWcbaWdbiaadAfacaWGxbaapaqabaaaaa@3963@ ) with transverse and shear component.
  3. Retrieve the material yield (Rp) value from the Points context.
  4. Calculate Static Strength ( σ S K , W MathType@MTEF@5@5@+= feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVCI8FfYJH8YrFfeuY=Hhbbf9v8qqaqFr0xc9pk0xbb a9q8WqFfeaY=biLkVcLq=JHqpepeea0=as0Fb9pgeaYRXxe9vr0=vr 0=vqpWqaaeaabiGaciaacaqabeaadaqaaqaaaOqaaabaaaaaaaaape Gaae4Wd8aadaWgaaWcbaWdbiaadofacaWGlbGaaiilaiaadEfaa8aa beaaaaa@3AE0@ )
    σ SK,W =Rp* α w  *  n pl  * ρ WEZ MathType@MTEF@5@5@+= feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVCI8FfYJH8YrFfeuY=Hhbbf9v8qqaqFr0xc9pk0xbb a9q8WqFfeaY=biLkVcLq=JHqpepeea0=as0Fb9pgeaYRXxe9vr0=vr 0=vqpWqaaeaabiGaciaacaqabeaadaqaaqaaaOqaaabaaaaaaaaape Gaae4Wd8aadaWgaaWcbaWdbiaadofacaWGlbGaaiilaiaadEfaa8aa beaak8qacqGH9aqpcaWGsbGaamiCaiaacQcacqaHXoqypaWaaSbaaS qaa8qacaWG3baapaqabaGcpeGaaeiOaiaabQcacaqGGcGaamOBa8aa daWgaaWcbaWdbiaadchacaWGSbaapaqabaGcpeGaaeiOaiaabQcacq aHbpGCpaWaaSbaaSqaa8qacaWGxbGaamyraiaadQfaa8aabeaaaaa@4E38@
    • a w MathType@MTEF@5@5@+= feaahqart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVCI8FfYJH8YrFfeuY=Hhbbf9v8qqaqFr0xc9pk0xbb a9q8WqFfeaY=biLkVcLq=JHqpepeea0=as0Fb9pgeaYRXxe9vr0=vr 0=vqpWqaaeaabiGaciaacaqabeaadaqaaqaaaOqaaabaaaaaaaaape Gaamyya8aadaWgaaWcbaWdbiaadEhaa8aabeaaaaa@3844@ = Weld Factor
    • n p l MathType@MTEF@5@5@+= feaahqart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVCI8FfYJH8YrFfeuY=Hhbbf9v8qqaqFr0xc9pk0xbb a9q8WqFfeaY=biLkVcLq=JHqpepeea0=as0Fb9pgeaYRXxe9vr0=vr 0=vqpWqaaeaabiGaciaacaqabeaadaqaaqaaaOqaaabaaaaaaaaape GaamOBa8aadaWgaaWcbaWdbiaadchacaWGSbaapaqabaaaaa@393B@ = Plastic support factor
    • ρ W E Z MathType@MTEF@5@5@+= feaahqart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVCI8FfYJH8YrFfeuY=Hhbbf9v8qqaqFr0xc9pk0xbb a9q8WqFfeaY=biLkVcLq=JHqpepeea0=as0Fb9pgeaYRXxe9vr0=vr 0=vqpWqaaeaabiGaciaacaqabeaadaqaaqaaaOqaaabaaaaaaaaape GaeqyWdi3damaaBaaaleaapeGaam4vaiaadweacaWGAbaapaqabaaa aa@3AA7@ = Softening factor
  5. Calculate static utilization (   a S K MathType@MTEF@5@5@+= feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVCI8FfYJH8YrFfeuY=Hhbbf9v8qqaqFr0xc9pk0xbb a9q8WqFfeaY=biLkVcLq=JHqpepeea0=as0Fb9pgeaYRXxe9vr0=vr 0=vqpWqaaeaabiGaciaacaqabeaadaqaaqaaaOqaaabaaaaaaaaape GaaiiOaiaadggapaWaaSbaaSqaa8qacaWGtbGaam4saaWdaeqaaaaa @3A15@ )
    a SK = σ VW σ SK,W / γ Stat MathType@MTEF@5@5@+= feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVCI8FfYJH8YrFfeuY=Hhbbf9v8qqaqFr0xc9pk0xbb a9q8WqFfeaY=biLkVcLq=JHqpepeea0=as0Fb9pgeaYRXxe9vr0=vr 0=vqpWqaaeaabiGaciaacaqabeaadaqaaqaaaOqaaabaaaaaaaaape Gaamyya8aadaWgaaWcbaWdbiaadofacaWGlbaapaqabaGcpeGaeyyp a0ZaaSaaa8aabaWdbiaabo8apaWaaSbaaSqaa8qacaWGwbGaam4vaa WdaeqaaaGcbaWdbiaabo8apaWaaSbaaSqaa8qacaWGtbGaam4saiaa cYcacaWGxbaapaqabaGcpeGaai4laiabeo7aN9aadaWgaaWcbaWdbi aadofacaWG0bGaamyyaiaadshaa8aabeaaaaaaaa@4909@
    • γ   S t a t MathType@MTEF@5@5@+= feaahqart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVCI8FfYJH8YrFfeuY=Hhbbf9v8qqaqFr0xc9pk0xbb a9q8WqFfeaY=biLkVcLq=JHqpepeea0=as0Fb9pgeaYRXxe9vr0=vr 0=vqpWqaaeaabiGaciaacaqabeaadaqaaqaaaOqaaabaaaaaaaaape Gaeq4SdC2damaaBaaaleaapeGaaiiOaiaadofacaWG0bGaamyyaiaa dshaa8aabeaaaaa@3CDD@ = Static Safety factor