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 Assign Material tab.

Parameter	Description
Size Effect (Ks)	default = 1.0
Temperature Factor (Kt)	default = 1.0
Surface Treatment (Ksur)	default = 1.0
Safety Factor for Strength (Mf)	default = 1.0
Loading Factor (Ff)	default = 1.0

The following are the parameters listed in My Material tab.

Parameter	Description
Detail Category for nominal (Δ σc, Basic)	Listed in SN tab (default = 160 N/mm2)
Detail Category for shear (Δ τc, Basic)	Listed in SN tab (default = 100 N/mm2)
Number of cycles at Constant Amplitude Fatigue Limit – nominal (NDσ)	Listed in SN tab (default = 5e6 cycles)
Number of cycles at Cut-Off Limit – nominal (NLσ)	Listed in SN tab (default = 1e8 cycles)
Slope before Constant Amplitude Fatigue Limit – nominal (m1σ)	Listed in SN tab (default = 3.0)
Slope before Cut-Off Limit – nominal (m2σ)	Listed in SN tab (default = 5.0)
Number of cycles at which the reference value of the fatigue strength is defined. (greyed out) – nominal (Ncσ)	Listed in SN tab (default = 2e6 cycles)
Number of cycles at Cut-Off Limit – shear (NLτ)	Listed in SN tab (default = 1e8 cycles)
Slope before Constant Amplitude Fatigue Limit – shear (m1τ)	Listed in SN tab (default = 5.0 )
Number of cycles at which the reference value of the fatigue strength is defined – shear (Ncτ)	Listed in SN tab (default = 2e6 cycles)

Formulation

Query Stress σ_xx, σ_yy, τ_xy (max and min across all loadcases)

Find the stress ranges (max – min) = ( Δσ_xx, Δσ_yy, and Δτ_xy)

Multiply Stress Range from Loading Factor Δσ

= Δ σ \cdot γ_{F f}

$= Δ σ \cdot γ_{F f}$

Calculate Corrected Fatigue Strength Δσ_C and Δτ_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

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

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

Calculate Constant Amplitude Fatigue Limit Δσ_D and Δτ_D

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

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

$Δ τ_{D} = Inf$ $Δ τ_{D} = Inf$

Calculate Stress at Cut-off Limit Δσ_L and Δτ_L

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

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

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

Calculate Permissible Number of Cycles N_perm

\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}

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

Component Damage

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

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

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

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

Equivalent Damage

D = \max (D_{δ, y}^{3} + D_{δ, x y}^{5}, D_{δ, x}^{3} + D_{δ, x y}^{5})

$D = \max (D_{δ, y}^{3} + D_{δ, x y}^{5}, D_{δ, x}^{3} + D_{δ, x y}^{5})$

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.