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BS EN 1993-1-9 : 2005
EN 1993-1-9 : 2005 (E)
Table 8.9: Orthotropic decks open stringers
Detail
Constructional detail Description Requirements
category
1) Connection of longitudinal 1) Assessment based on the direct
stringer to cross girder. stress range in the stringer.
80 t 12mm
1
71 t>12mm
t
2) Connection of continuous 2) Assessment based on
s s
longitudinal stringer to cross combining the shear stress range
girder. and direct stress range in
the web of the cross girder, as an
equivalent stress range:
Ms
1
Wnet,s
eq 2 4 2
2
Vs
s s
A
56 w,net,s
s
2 Check also stress range between
stringers as defined in EN 1993-
2.
s
Table 8.10: Top flange to web junction of runway beams
Detail
Constructional detail Description Requirements
category
1) Rolled I- or H-sections 1) Vertical compressive stress
range vert. in web due to wheel
160 loads
2) Full penetration tee-butt weld 2) Vertical compressive stress
range vert. in web due to wheel
71 loads
3) Partial penetration tee-butt
3) Stress range vert. in weld
welds, or effective full
throat due to vertical compression
penetration tee-butt weld
36* from wheel loads
conforming with EN 1993-1-8
4) Fillet welds
4) Stress range vert. in weld
throat due to vertical compression
from wheel loads
36*
5) T-section flange with full 5) Vertical compressive stress
penetration tee-butt weld range vert. in web due to wheel
loads
71
6) T-section flange with partial
6) Stress range vert. in weld
penetration tee-butt weld, or
throat due to vertical compression
effective full penetration tee-butt
from wheel loads
36*
weld conforming with
EN 1993-1-8
7) T-section flange with fillet
7) Stress range vert. in weld
welds
throat due to vertical compression
from wheel loads
36*
29
Licensed copy: BSI USER 06 Document Controller, Midmac Contracting Co. W.L.L, Version correct as of 05/06/2011 14:51, (c) BSI
BS EN 1993-1-9 : 2005
EN 1993-1-9 : 2005 (E)
Annex A [normative] Determination of fatigue load parameters and
verification formats
A.1 Determination of loading events
(1) Typical loading sequences that represent a credible estimated upper bound of all service load events
expected during the fatigue design life should be determined using prior knowledge from similar structures,
see Figure A.1 a).
A.2 Stress history at detail
(1) A stress history should be determined from the loading events at the structural detail under
consideration taking account of the type and shape of the relevant influence lines to be considered and the
effects of dynamic magnification of the structural response, see Figure A.1 b).
(2) Stress histories may also be determined from measurements on similar structures or from dynamic
calculations of the structural response.
A.3 Cycle counting
(1) Stress histories may be evaluated by either of the following cycle counting methods:
rainflow method
reservoir method, see Figure A.1 c).
to determine
stress ranges and their numbers of cycles
mean stresses, where the mean stress influence needs to be taken into account.
A.4 Stress range spectrum
(1) The stress range spectrum should be determined by presenting the stress ranges and the associated
number of cycles in descending order, see Figure A.1 d).
(2) Stress range spectra may be modified by neglecting peak values of stress ranges representing less than
1% of the total damage and small stress ranges below the cut off limit.
(3) Stress range spectra may be standardized according to their shape, e.g. with the coordinates 1,0
and n 1,0 .
30
Licensed copy: BSI USER 06 Document Controller, Midmac Contracting Co. W.L.L, Version correct as of 05/06/2011 14:51, (c) BSI
BS EN 1993-1-9 : 2005
EN 1993-1-9 : 2005 (E)
A.5 Cycles to failure
(1) When using the design spectrum the applied stress ranges should be multiplied by and the
i Ff
fatigue strength values C divided by Mf in order to obtain the endurance value NRi for each band in the
spectrum. The damage Dd during the design life should be calculated from:
n
nEi
Dd (A.1)
NRi
i
where nEi is the number of cycles associated with the stress range Ff i for band i in the factored
spectrum
C
NRi is the endurance (in cycles) obtained from the factored NR curve for a stress range of
Mf
Ff i
(2) On the basis of equivalence of Dd the design stress range spectrum may be transformed into any
equivalent design stress range spectrum, e.g. a constant amplitude design stress range spectrum yielding the
fatigue equivalent load Qe associated with the cycle number nmax = ni or QE,2 associated with the cycle
number NC = 2 106.
A.6 Verification formats
(1) The fatigue assessment based on damage accumulation should meet the following criteria:
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