FKM Classification Parameters (Non-Welded)
The parameters for non-welded calculations are listed in both the Assign Material tab and the My Material tab of the Assign Material dialog.
The defaults are with respect to material = steel.
The following are the parameters listed in Assign Material tab.
Parameter | Description |
---|---|
Effective Diameter (Deff) | Effective diameter of the semi-finished product (default = 7.5mm) |
Anisotropy factor (KA) | Default = 0.9 |
Plastic Notch Factor – Nominal (Kp_sigma) | Default = 1 |
Plastic Notch Factor – Shear (Kp_tau) | Default = 1 |
Relative Stress Gradient X (G_sigmax) | Relative stress gradient in normal direction (Default = 0.1 mm-1) |
Relative Stress Gradient Y (G_sigmay) | Relative stress gradient in normal direction (Default = 0.1 mm-1) |
Relative Stress Gradient XY (G_sigmaxy) | Relative stress gradient in shear direction (Default = 0.1 mm-1) |
Overload Factor (Overloading) | Parameter to decide overload situation. Options: F1, F2, F3, F4. Based on the selection, the fatigue limit calculation formula may vary. (Default – F2) |
Reference Number of cycles (N’) | Reference number of cycles for fatigue strength assessment (Default = 2e6) |
Surface Roughness (Rz) | Average roughness of the component surface, (default = 100 μm) |
Surface Treatment Factor (Kv) | Default = 1 |
Coating Factor (Ks) | Default = 1 |
Temperature Factor (Ktd) | Default = 1 |
Material Safety factor (jF) | Material safety factor for non-welded steel based on regular inspection (default = 1.5) |
Load Safety factor (jS) | Safety factor defined by design loads (default = 1.0) |
Partial safety factor for allowable defects in castings (jG) | Material safety factor for Casted materials (default =1, as just steel is supported) |
Total Safety Factor (jD) |
Total safety factor, based on jF, jS, jD and KT,D , jD = jS . (jF/ KT,D) |
The following are the parameters listed in My Material tab.
Parameter | Description |
---|---|
Tensile Strength (Rm) | Listed in SN tab (default = 300 N/mm2) |
Yield Strength (Rp) | Listed in SN tab (default = 180 N/mm2) |
Elastic Modulus (E) | Listed in SN tab (default = 2e5 N/mm2) |
Strain At Break Point (A%) | Listed in SN tab (default = 10% or 0.1) |
Normal Fatigue Limit (σ_wzd) | Listed in SN tab (default = 140 N/mm2) |
Shear Fatigue Limit (τ_wzd) | Listed in SN tab (default = 80 N/mm2) |
Number of Cycles at Knee Point, Normal Stress (Nd_σ) | Listed in SN tab (default = 1e6 cycles) |
Number of Cycles at Knee Point, Shear Stress (Nd_τ) | Listed in SN tab (default = 1e6 cycles) |
SN curve slope, Normal Stress (K_σ) | Listed in SN tab (default = 5) |
SN curve slope, Shear Stress (K_τ) | Listed in SN tab (default = 8) |
Fatigue Stress Factor, Fully Reversed, Normal (fw_σ) | Listed in Other tab (default = 0.4) |
Fatigue Stress Factor, Fully Reversed, Shear (fw_τ) | Listed in Other tab (default = 0.577) |
Constant, Technological Size Factor for Tensile Strength (adm) | Listed in Other tab (default = 0.15) |
Constant, Technological Size Factor for Yield Strength (adp) | Listed in Other tab (default = 0.4) |
Constant, Technological Size Factor @ adm (Deff,N,m) | Listed in Other tab (default = 40mm) |
Non-linear Strain Stress Factor under bending – GJL (KNL) | Listed in Other tab (default = 1.0) |
aG Constant for (Kt-Kf) ratio for Fatigue Strength Factor (aG) | Listed in Other tab (default = 0.4) |
bG Constant for (Kt-Kf) ratio for Fatigue Strength Factor (bG) | Listed in Other tab (default = 2400) |
Constant For Roughness Factor, Normal Stress (aR_σ) | Listed in Other tab (default = 0.22) |
Minimum permissible tensile strength constant (Rm,N,min) | Listed in Other tab (default = 400 N/mm2) |
Constant for Mean Stress Sensitivity (aM) | Listed in Other tab (default = 0.35) |
Constant for Mean Stress Sensitivity (bM) | Listed in Other tab (default = -0.1) |
Compression Strength Factor, for tension, compression (f_σ) | Listed in Other tab (default = 1.0) |
Compression Strength Factor, Shear (f_τ) | Listed in Other tab (default = 1.0) |
Material Parameter Epsilon_0 (Epsilon_0) | Listed in Other tab (default = 0.05) |
Ductility factor (q) | Listed in Other tab (default = 0) |
Formulation
Current support in the evaluation build is for steel only.
Cyclic degree of utilization for normal and shear stresses:
- Assessment
- [ Stress amplitude / (critical amplitude/total safety factor)]
- Master Assessment Calculation
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