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thickness with a non-uniform
stress distribution
• the stress distribution along
the length of the weld is constant
FIGURE VI.4
t1
t2
g1
a
a
apen
EXAMPLE OF UNIFORM STRESS DISTRIBUTION
FIGURE VI.5
EXAMPLE OF NON UNIFORM STRESS DISTRIBUTION
FIGURE VI.6
τ τ
τ τ
70
ALUMINIUM IN COMMERCIAL VEHICULES CHAPTER VI DESIGN AND CALCULATION 70 | 71
The forces acting on a fillet weld
shall be resolved into stress components
with respect to the
throat section (see Figure VI.7).
These components are:
σ⊥ : normal stress perpendicular
to the throat section
σ⎜⎜ : normal stress parallel to the
weld axis
τ⊥ : shear stress acting on the
throat section perpendicular to
the weld axis
τ⎜⎜ : shear stress acting on the
throat section parallel to the
weld axis
Design formula for fillet weld:
√σ2
⊥ + 3 . (τ2
⊥ + τ2
II ) ≤
fw
γMw
FIGURE VI.7
σ⊥
σII
F,σ
a
τII
τ τ⊥
71
EUROPEAN ALUMINIUM ASSOCIATION
7.3.4. Heat affected zone
The stress in the heat affected
zone has to be checked. The
stress is calculated for the smallest
failure plane for both butt
welds and fillet welds. The
sketches below (ref. BS 8118)
indicate the failure plane for
some welds (Figures VI.8, VI.9,
VI.10, VI.11):
W: weld metal, check of weld
F: heat affected zone, check of
fusion boundary
T: heat affected zone, check of
cross section
BUTT WELD
FIGURE VI.8
t
F W F
Pv
Pa
Pv
Pa
T BUTT WELD
FIGURE VI.10
T FILLET WELD
FIGURE VI.11
Pv
Pa
Pv
Pa
W
F
T
t
F
t
FILLET WELD
FIGURE VI.9
t
Pv
Pa
T
T T
F
W
t
Pv
Pa
T
T T
F
W W
F
F F
72
ALUMINIUM IN COMMERCIAL VEHICULES CHAPTER VI DESIGN AND CALCULATION 72 | 73
7.4. Bolted connections
The rules for bolted connections are
given in EN 1999-1-1, clause 8.5.
Minimum, regular and maximum
spacing, end and edge distances
for bolts are given in the Table
VI.4.
Minimum Regular Maximum
e1 = 1.2 . d0
e2 = 1.2 . d0
p1 = 2.2 . d0
p2 = 2.2 . d0
e1 = 2.0 . d0
e2 = 1.5 . d0
p1 = 2.5 . d0
p2 = 3.0 . d0
e1 = 4 . t + 40mm
e2 = 4 . t + 40mm
p1 ≤ { 14 . t
200mm
p2 ≤ { 14 . t
200mm
p1 = 2.2 . d0
p2 = 2.4 . d0
p1 = 2.5 . d0
p2 = 3.0 . d0
p1 ≤ { 14 . t
200mm
p2 ≤ { 14 . t
200mm
p1 = 2.2 . d0 p1 = 2.5 . d0
Outer lines:
p1 ≤ { 14 . t
200mm
Inner lines:
p1 ≤ { 28 . t
400mm
The maximum clearance for fitted
bolts is 0.3 mm and for nonfitted
bolts 1.0 mm.
Failure modes for bolted connections
may be:
• block tearing, failure in shear
in a row of bolts along the shear
face of a bolt group and tension
failure along the tension face of
the bolt group
• shear failure in the bolt
• bearing failure of the bolt hole
• tension failure of the bolt
• punching shear around the
bolt head or nut
• combined shear and tension
failure
o) outer line i) inner line
d0 is the diameter of the hole and t = thickness of the plate
TABLE VI.4
73
EUROPEAN ALUMINIUM ASSOCIATION
Failure mode Formula Parameters
Shear
resistance per
shear plane
Fv,Rd =
αv . fub . A
γM2
αv = 0.6 for steel bolts, 4.6, 5.6 and 8.8
αv = 0.5 for steel bolts, 4.8, 5.8, 6.8 and 10.9
αv = 0.5 for stainless steel and aluminium bolts
A is the cross-section of the bolt at the shear plane
Bearing
resistance Fb,Rd =
k1 . αb . fu . d . t
γM2 k1 = smallest of
2.8
e2 - 1.7
d0 { 2.5
for edge bolts
k1 = smallest of
1.4
p2 - 1.7
d0 { 2.5
for inner bolts
αb = smallest of
αd
fub
fu {1.0
αd =
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