Eurocode 3 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 the Assign Material tab.


Parameter	Description
Size Effect ( $K s$ )	default = 1.0
Temperature Factor ( $K t$ )	default = 1.0
Surface Treatment ( $K s u r$ )	default = 1.0
Safety Factor for Strength ( $M f$ )	default = 1.0
Loading Factor ( $F f$ )	default = 1.0

The following are the parameters listed in the My Material tab.


Parameter	Description
Detail Category for nominal ( $Δ σ c$ , Basic)	Listed in SN tab (default = 160 N/mm2)
Detail Category for shear ( $Δ τ c$ , Basic)	Listed in SN tab (default = 100 N/mm2)
Number of cycles at Constant Amplitude Fatigue Limit – nominal ( $N D σ$ )	Listed in SN tab (default = 5e6 cycles)
Number of cycles at Cut-Off Limit – nominal ( $N L σ$ )	Listed in SN tab (default = 1e8 cycles)
Slope before Constant Amplitude Fatigue Limit – nominal ( $m l σ$ )	Listed in SN tab (default = 3.0)
Slope before Cut-Off Limit – nominal ( $m 2 σ$ )	Listed in SN tab (default = 5.0)
Number of cycles at which the reference value of the fatigue strength is defined. (greyed out) – nominal ( $N c σ$ )	Listed in SN tab (default = 2e6 cycles)
Number of cycles at Cut-Off Limit – shear ( $N L τ$ )	Listed in SN tab (default = 1e8 cycles)
Slope before Constant Amplitude Fatigue Limit – shear ( $m l τ$ )	Listed in SN tab (default = 5.0 )
Number of cycles at which the reference value of the fatigue strength is defined – shear ( $N c τ$ )	Listed in SN tab (default = 2e6 cycles)

Formulation

Query Stress $σ_{x x}$ , $σ_{y y}$ , $τ_{x y}$ (max and min across all loadcases)

Find the stress ranges (max – min) = (

Δ σ_{x x}

Δ σ_{y y}

, and

Δ τ_{x y}

)

Multiply Stress Range from Loading Factor $Δ σ$

= Δ σ \cdot γ_{F f}

Calculate Corrected Fatigue Strength $Δ σ_{C}$ and $Δ τ_{C}$

Δ σ_{C} = [\frac{Δ σ_{C, B a s i c}}{γ_{M f}}] \cdot k s \cdot k t \cdot k s u r

$Δ τ_{C} = [\frac{Δ τ_{C, B a s i c}}{γ_{M f}}] \cdot k s \cdot k t \cdot k s u r$

Calculate Constant Amplitude Fatigue Limit $Δ σ_{D}$ and $Δ τ_{D}$

Δ σ_{D} = Δ σ_{C} {(\frac{N_{c σ}}{N_{D σ}})}^{\frac{1}{m_{1 σ}}}

$Δ τ_{D} = Inf$

Calculate Stress at Cut-off Limit $Δ σ_{L}$ and $Δ τ_{L}$

Δ σ_{L} = Δ σ_{D} {(\frac{N_{D σ}}{N_{L σ}})}^{\frac{1}{m_{2 σ}}}

$Δ τ_{L} = Δ τ_{C} {(\frac{N_{c τ}}{N_{L τ}})}^{\frac{1}{m_{1 τ}}}$

Calculate Permissible Number of Cycles $N_{p e r m}$

\begin{array}{l} For Δ σ \\ If Δ σ_{(stress range)} > Δ σ_{D,} \\ N_{p e r m} = N_{D ​ σ} {(\frac{Δ σ}{Δ σ_{D}})}^{- m_{1 σ}} \\ If Δ σ_{D} > Δ σ \geq Δ σ_{L,} \\ N_{p e r m} = N_{D ​ σ} {(\frac{Δ σ}{Δ σ_{D}})}^{- m_{2 σ}} \\ If Δ σ < Δ σ_{L,} \\ N_{p e r m} = Inf \\ For Δ τ \\ If Δ τ_{(stress range)} \geq Δ τ_{C,} \\ N_{p e r m} = N_{C τ} {(\frac{Δ τ}{Δ τ_{C}})}^{- m_{1 τ}} \\ If Δ τ_{(stress range)} < Δ τ_{L,} \\ N_{p e r m} = Inf \end{array}

Component Damage

D_{x} = \frac{N}{N_{p e r m ​ x}} < 1.0

$D_{y} = \frac{N}{N_{p e r m y}} < 1.0$

$D_{x y} = \frac{N}{N_{p e r m x y}} < 1.0$

Equivalent Damage

D = \max (D_{δ, y}^{} + D_{δ, x y}^{}, D_{δ, x}^{} + D_{δ, x y}^{})

Note: DIN is the copyright owner for

EN 1999-1-3:2011-11 (November
                        2011)

. Permission to use and reproduce information contained in the Eurocode 3 standards was granted by DIN.