Checking according to EN13001 standard in SDC Verifier

Crane Standard EN 13001-3-1+A2 Limits States and proof competence of steel structure is implemented in SDC Verifier. The standard is to be used together with EN13001-1 and EN13001-2:

EN 13001-3-1 standard deals only with the limit state method. The allowable stress method is reliable in specific cases – for cranes where all masses act only unfavorable with linear relationship between load actions and load effects.

To account for the uncertainty of fatigue strength values and possible consequences of fatigue damage – fatigue strength specific resistance factor should be specified:

Characteristic fatigue strength (fatigue strength at 2 million cycles) and slope constant have to be defined to calculate limit design stress range:

\(\Delta \sigma _{Rd} =\frac{\Delta \sigma _{c}}{\gamma _{mf} \times \sqrt[m]{s_{m}}}\)

Where

• Δσ_c  —  Is the characteristic fatigue strength (Annex D and Annex H of standard)
• m  —  Is the slope constant of the log Δσ – logN curve (Annex D and Annex H of EN13001 standard)
• ϒ_mf  —  Is the fatigue strength specific resistance factor (see table above)
• s_m  —  Is the stress history parameter

Characteristic fatigue strength

Fatigue Strength Parallel to the weld:

See how SDC Verifier calculates fatigue strength parallel to the weld

Detail No.	Δσc Δṫc	Constructional detail	Requirements
3.7	m = 3	Normal stress in weld direction	Special conditions: no irregularities from start-stop-points in quality level + 1 NC welding with restraint of shrinkage – 1 NC
	180	Continuous weld, quality level B
	140	Continuous weld, quality level C
	80	Intermittent weld, quality level C

Fatigue Strength Perpendicular to the weld for welded parts:

See how SDC Verifier calculates fatigue strength perpendicular to the weld

Fatigue Strength Perpendicular to the weld for non-welded parts:

3.28		Continuous component to which parts are welded transversally	Basic conditions: plate thickness t≤ 12 mm c ≥ 10 mm quality level D not allowed for K-weld Special conditions: plate thickness t > 12 mm (Double fillet welds only) -1 NС  c < 10 mm -1 NС K-weld instead  of double fillet weld +1 NC quality level D instead of C  – 1 NC
	112	Double fillet weld, quality level B*
	100	Double fillet weld, quality level B
	90	Double fillet weld, quality level C
	80	Single fillet weld, quality level B, C
	80	Partial penetration V-weld on remaining backing, quality level  B, C

Fatigue Strength Shear direction to the welds:

See how SDC Verifier calculates fatigue strength in shear direction to the weld

Detail No.	Δσc Δṫc N|mm 2	Constructional detail	Requirements
3.34	m = 5	Continuous groove weld, single or double fillet weld under uniform shear flow	Basic conditions: quality level C components with usual residual stresses Special conditions: components with considerable residual stresses (e.g. joint of components with restraint of shrinkage) -1 NC no initial points +1 NC
	112	With full penetration
	90	Partial penetration

SDC Verifier defines all fatigue strength classification

For Direct use of stress history option SDC Verifier will calculate automatically stress history for slope constant 3 and 5 and use it to calculate limit design stress range. Alternatively, user can set manually class S for different directions (parallel, perpendicular to the weld).

SDC Verifier calculate cumulative damage based on Palmgren-Miner rule:

\(\sum ^{k}_{i=1}\frac{n_{i}}{N_{i}} \ =\ C\)

Where

• n_i is the number of cycles accumulated at stress S_i
• C is the fraction of life consumed by exposure to the cycles at the different stress levels

Cumulative damage according to EN13001 calculated in SDC Verifier: