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Welded joints examplesCelsius®355 NH
Welded Joints Examples Contents
2
CONTENTS
RHS T-Joint Moment in Plane 03CHS Gap K-Joint 09CHS Overlap K-Joint 12RHS Gap K-Joint 15RHS Overlap K-Joint 21RHS Chord CHS Bracings Gap K-Joint 23RHS Chord CHS Bracings Overlap K-Joint 82.7 29RHS Chord CHS Bracings Overlap K-Joint 102.7 33RHS Chord RHS Bracings Overlap KT-Joint 36CHS Chord CHS Bracings Gap KT-Joint 41CHS Chord CHS Bracings Overlap KT-Joint 46UB Chord RHS Bracings Gap K-Joint 52
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Welded Joints Examples RHS T-Joint Moment In Plane
1 RHS T-Joint Moment In Plane
3
References are generally to Tata Steel publication ‘Design of Welded Joints’ (unless otherwise stated).
SHS 150 x 150 x 10All material Celsius 355 to EN 10210
RHS 150 x 150 x 8
90º
N1,Ed = 19.2 kN Mip,1,Ed = 54 kNm
Np,Ed = 350 kNMip,0,Ed = 16.6 kNm
N0,Ed = 136 kN Mip,0,Ed = 35.8 kNm
Dimensions b0 = 150 mm b1 = 150 mm h0 = 150 mm h1 = 150 mm t0 = 10.0 mm t1 = 8.0 mm Validity limits check Chord: (b0-3 t0)/t0 ; (h0-3 t0)/t0 ≤ 38ε (Class 1 or 2 compression) 38ε = 38 √(235/fy0) = 38√(235/355) = 30.92 (b0-3 t0)/t0 = (150-3 x 10)/10 = 12 ∴PASS (h0-3 t0)/t0 = (150-3 x 10)/10 = 12 ∴PASS b0/t0 ≤ 35 b0/t0 = 150/10 = 15 ∴PASS h0/t0 ≤ 35 h0/t0 = 150/10 = 15 ∴PASS Compression brace: bi/ti ; hi/ti ≤ 35 b1/t1 = 150/8 =18.75 ∴PASS h1/t1 = 150/8 =18.75 ∴PASS Compression brace: (b1-3 t1)/t1 ; (h1-3 t1)/t1 ≤ 38ε (Class 1 or 2 compression) 38ε = 38 √(235/fy0) = 38√(235/355) = 30.92 (b1-3 t1)/t1 = (150-3 x 8)/8 = 15.75 ∴PASS (h1-3 t1)/t1 = (150-3 x 8)/8 = 15.75 ∴PASS 0.25 ≤ bi/b0 ≤ 1.0 b1/b0 = 150/150 = 1.0 ∴PASS 0.5 ≤ h0/b0 ≤ 2.0 h0/b0 = 150/150 = 1.0 ∴PASS 0.5 ≤ hi/bi ≤ 2.0 h1/b1 = 150/150 = 1.0 ∴PASS 30° ≤ θi ≤ 90° θ1 = 90° ∴PASS
Reference
5.3.1 Figure 37
(EN 1993-1-1) Table 5.2
(EN 1993-1-1) Table 5.2
Welded Joints Examples RHS T-Joint Moment In Plane
4
Axial: Chord face failure (deformation) (valid when β ≤ 0.85)
required not check0.1150150
bb
0
1 ∴===β
Although this check is not required in this particular case, the chord end stress factor calculation for is shown below for information as it includes moments;
RHS chord end stress factor, kn RHS chord most compressive stress, σ0,Ed;
0,op,el
Ed,0,op
0,ip,el
Ed,0,ip
0
Ed,0Ed,0 W
M
W
M
AN
++=σ
Note: Moment is additive to compressive stress which is positive for moments. For RHS chords use most compressive chord stress. A0 = 54.9 cm2 = 5490 mm2
32Ed,010236
100010008.35109.54
1000136×
××+
×
×=σ
2
Ed,0 mm/N47.176=σ Chord factored stress ratio, n;
⎟⎠
⎞⎜⎝
⎛=⎟
⎟⎠
⎞⎜⎜⎝
⎛ σ=
35547.176
fn
0y
Ed,0
497.0n =
Using formulae: Using graph: For n > 0 (compression):
β−=
n4.03.1kn but kn ≤ 1.0
0.10.1
497.04.03.1kn ≤×
−=
0.1k0.1but101.1k nn =∴≤=
From graph, for β = 1.0; kn = 1.0
(However, not required in this case as chord deformation not critical as β>0.85)
Reference 5.3.3
6.3
5.3.2.1
5.3.2.1
5.3.2.1Fig. 38
5.3.2.1
Welded Joints Examples RHS T-Joint Moment In Plane
5
Axial: Chord shear (valid for X-joints with Cos θ1 > h1/h0) As this is a T-joint with θ1 = 90° this check is not required. Axial: Chord side wall buckling (valid when β = 1.0) β = 1.0 ∴check required
5M01
1
1
0bnRd,1 /t10
sinh2
sintfk
N γ⎟⎟⎠
⎞⎜⎜⎝
⎛+
θθ=
Chord side wall buckling strength, fb For compression brace, T-joint:
0y
i0
0
fE
sin12
th
46.3π
θ⎟⎟⎠
⎞⎜⎜⎝
⎛−
=λ where: E = 210000 N/mm2
589.0
355210000
90sin12
10150
46.3 =
π
°⎟⎠
⎞⎜⎝
⎛ −
=λ
Using formulae: Using graph: From EN 1993-1-1:2005, 6.3.1.2, flexural buckling reduction factor, χ; From EN 1993-1-1:2005, table 6.1, 21.0=α (curve ‘a’)
( )( )2 2.015.0 λ+−λα+=φ
( )( ) 714.0589.02.0589.021.015.0 2 =+−+=φ
1.0but122
≤χλ−φ+φ
=χ
1.0but589.0714.0714.0
122
≤χ−+
=χ
895.0=χ
From graph, for
589.0=λ ;
895.0=χ
0yb ff χ= (for T- and Y-joints with compression in bracing) 2
b N/mm318355895.0f =×=
0.1/101090sin1502
90sin103180.1N Rd,1 ⎟⎟
⎠
⎞⎜⎜⎝
⎛×+
°×
°××
=
Reference 5.3.3
5.3.3
5.3.3
5.3.2.3
6.1 (For ‘E’)
5.3.2.3
(EN 1993-1-1) Table 6.1 (EN 1993-1-1) 6.3.1.2
5.3.2.3 Fig. 40
Welded Joints Examples RHS T-Joint Moment In Plane
6
Axial: Chord punching shear
(valid when 0.85 ≤ β ≤ 1 – 1/γ)
5.7102
150t2
b
0
0 =×
==γ
867.05.7
110.185.0 =−≤≤
∴Check not required Axial: Bracing failure (effective width) (valid when β ≥ 0.85) β = 1.0 ∴check required ( ) 5Mi,eff1i11yRd,1 /b2t4h2tfN γ+−= where:
ii,effiiyi
00y
0
0i,eff bbbutb
tftf
bt10b ≤×=
mm 150bbutmm 1251508355
10355150
1010b i,effi,eff ≤=×××
××
=
beff,i = 125 mm ( ) 0.1/12528415028355N Rd,1 ×+×−××= PASS kN 2.19kN1471N Rd,1 ∴>= Moment in plane: Chord face failure (deformation) (valid when β ≤ 0.85)
required not check0.1150150
bb
0
1 ∴===β
Reference 5.3.3
6.3
5.3.3
6.3
5.3.3
5.3.2.2
5.3.5.1
6.3
Welded Joints Examples RHS T-Joint Moment In Plane
7
Moment in plane: Chord side wall crushing (valid when 0.85 < β ≤ 1.0)
required check0.1150150
bb
0
1 ∴===β
( ) 5M
2010ykRd,1,ip /t5htf5.0M γ+=
where: fyk = fy0 (for T-joints)
∴ fyk = 355 N/mm2 ( ) 0.1/105150103555.0M 2
Rd,1,ip ×+××= PASS kNm 54kNm71M Rd,1,ip ∴>= Moment in plane: Bracing failure (effective width) (valid when 0.85 < β ≤ 1.0)
required check0.1150150
bb
0
1 ∴===β
( ) 5M11111
1,eff1,ip,pl1yRd,1,ip /tthb
bb
1WfM γ⎥⎥⎦
⎤
⎢⎢⎣
⎡−⎟⎟
⎠
⎞⎜⎜⎝
⎛−−=
where: Wpl,ip,1 = 237 cm3 = 237000 mm3 beff,1 = 125 mm
( ) 0.1/881501501501251237000355M Rd,1,ip ⎥
⎦
⎤⎢⎣
⎡−⎟
⎠
⎞⎜⎝
⎛ −−=
PASS kNm 54kNm1.74M Rd,1,ip ∴>= Summary Axial joint resistance for brace 1 limited by chord side wall buckling and moment in plane resistance by chord side wall crushing resistance. Axial joint resistance, PASS kN 2.19kN1272N Rd,1 ∴>= Moment in plane joint resistance, PASS kNm 54kNm71M Rd,1,ip ∴>=
Reference 5.3.5.1
6.3
5.3.5.1
5.3.2.4
5.3.5.1
6.3
5.3.5.1
Welded Joints Examples RHS T-Joint Moment In Plane
8
Interaction check When more than one type of force exists, e.g. axial and moments in plane, an interaction check is required;
0.1M
M
M
M
N
N
Rd,i,op
Ed,i,op
Rd,i,ip
Ed,i,ip
Rd,i
Ed,i≤++ (for RHS chords)
As there are no moments out of plane;
776.0M
07154
12722.19
Rd,i,op=++
PASS 000.1776.0 ∴≤
Reference 2.3
Welded Joints Examples CHS Gap K-Joint
2 CHS Gap K-Joint
9
References are generally to Tata Steel publication ‘Design of Welded Joints’ (unless otherwise stated).
N1,Ed = 500 kN N2,Ed = - 400 kN
CHS 219.1x12.5All material CELSIUS 355 to EN 10210
CHS 139.7x5.0 CHS 114.3x3.6
45º45º
40
Np,Ed = 1000 kN N0,Ed = 1636 kN
Note: Brace 1 usually designated compression and brace 2 tension. Dimensions d0 = 219.1 mm d1 = 139.7 mm d2 = 114.3 mm t0 = 12.5 mm t1 = 5.0 mm t2 = 3.6 mm
Validity limits check 10 ≤ d0/t0 ≤ 50 d0/t0 = 219.1/12.5 = 17.53 ∴PASS d0/t0 ≤ 70ε2 (Class 1 or 2 for compression chord) 70ε2 = 70 [√(235/fy0)]
2 = 70(235/355) = 46.34 17.53 < 46.34 ∴PASS di/ti ≤ 70ε2 (Class 1 or 2 for compression brace) 70ε2 = 70 [√(235/fy0)]
2 = 70(235/355) = 46.34 d1/t1 = 139.7/5.0 = 27.94 < 46.34 ∴PASS di/ti ≤ 50 d1/t1 = 139.7/5.0 = 27.94 ∴PASS d2/t2 = 114.3/3.6 = 31.75 ∴PASS 0.2 ≤ di/d0 ≤ 1.0 d1/d0 = 139.7/219.1 = 0.64 ∴PASS d2/d0 = 114.3/219.1 = 0.52 ∴PASS -0.55 d0 ≤ e ≤ +0.25 d0 -0.55 x 219.1 ≤ e ≤ +0.25 x 219.1 -120.5 ≤ e ≤ +54.8 e = 0 mm ∴PASS g ≥ t1 + t2 t1 + t2 = 5 + 3.6 = 8.6 mm g = 40 mm ∴PASS 30° ≤ θ i ≤ 90° θ1 = 45° ∴PASS θ2 = 45° ∴PASS
Reference
5.1.1 Figure 27
(EN 1993-1-1) Table 5.2
(EN 1993-1-1)
Table 5.2
Welded Joints Examples CHS Gap K-Joint
10
Chord face failure (deformation)
Compression brace (1):
5M0
1
1
200ypg
Rd,1 /dd2.108.1
sintfkk
Nfailure, face Chord γ⎟⎟⎠
⎞⎜⎜⎝
⎛+
θ=
Gap/lap function, kg
764.85.122
1.219t2
d
0
0 =×
==γ
Using formulae: Using graph:
( )⎥⎥⎦
⎤
⎢⎢⎣
⎡
−+γ
+γ=33.1t/g5.0exp1
024.01k0
2.12.0
g
Note: g is positive for a gap and negative for an overlap
( )⎥⎥⎦
⎤
⎢⎢⎣
⎡
−×+×
+=33.15.12/405.0exp1
764.8024.01764.8k2.1
2.0g
761.1kg =
from graph; g/t0 = 40/12.5 = 3.2 kg = 1.761
CHS chord end stress factor, kp CHS chord least compressive applied factored stress, σp,Ed;
0,op,el
Ed,0,op
0,ip,el
Ed,0,ip
0
Ed,pEd,p W
M
W
M
AN
++=σ
Note: Moment is additive to compressive stress which is positive for moments. For CHS chords use least compressive chord stress.
22Ed,p N/mm30.123
101.8110001000
=×
×=σ
Chord factored stress ratio, np; 347.0355
30.123f
n0y
Ed,pp =⎟
⎠
⎞⎜⎝
⎛=⎟⎟⎠
⎞⎜⎜⎝
⎛ σ=
Using formulae: Using graph: For np > 0 (compression): kp = 1 - 0.3 np (1 + np) but ≤ 1.0
( ) 0.1but347.01347.03.01kp ≤+×−=
860.0kp =
from graph; kp = 0.860
Reference 5.1.3
6.3
5.1.2.2
5.1.2.1
5.1.2.1
5.1.2.1
5.1.2.2 Fig.29
5.1.2.1 Fig.28
Welded Joints Examples CHS Gap K-Joint
11
0.1/1.2197.1392.108.1
45sin5.12355860.0761.1N
2
Rd,1 ⎟⎠
⎞⎜⎝
⎛ +°
×××=
kN986N Rd,1 = Tension brace (2):
Rd,12
1Rd,2 N
sinsin
Nθθ
=
98645sin45sinN Rd,2 ×
°°
=
kN986N Rd,2 = Chord punching shear (valid when di ≤ d0 – 2 t0) di ≤ d0 – 2 t0
di ≤ 219.1 – 2 x 12.5 = 194.1 mm d1 = 139.7 mm < 194.1 mm ∴check chord punching shear d2 = 114.3 mm < 194.1 mm ∴check chord punching shear
5M
i2
ii0
0yRd,i /
sin2
sin1dt
3
fN γ
θ
θ+π=
Brace (1):
0.1/
45sin245sin17.1395.12
3355N
2Rd,1°
°+××π××=
kN1919N Rd,1 = Brace (2):
0.1/
45sin245sin13.1145.12
3355N
2Rd,2°
°+××π××=
kN1570N Rd,2 = Joint strength dictated by chord face failure for both bracings; PASS kN 500kN986N,resistance joint 1 Brace Rd,1 ∴>= PASS kN 400kN986N,resistance joint 2 Brace Rd,2 ∴>=
Reference
5.1.3
5.1.3
Welded Joints Examples CHS Overlap K-Joint
3 CHS Overlap K-Joint
12
References are generally to Tata Steel publication ‘Design of Welded Joints’ (unless otherwise stated).
N1,Ed = 500 kN
Np,Ed = 1000 kN CHS 219.1x12.5All material CELSIUS 355 to EN 10210
CHS 139.7x5.0
N2,Ed = - 400 kN
N0,Ed = 1636 kN
CHS 114.3x3.6
45º45º
- 45
e = - 42.2
Note: Brace 1 usually designated compression and brace 2 tension Dimensions
d0 = 219.1 mm d1 = 139.7 mm d2 = 114.3 mm t0 = 12.5 mm t1 = 5.0 mm t2 = 3.6 mm Validity limits check 10 ≤ d0/t0 ≤ 50 d0/t0 = 219.1/12.5 = 17.53 ∴PASS d0/t0 ≤ 70ε2 (Class 1 or 2 for compression chord) 70ε2 = 70 [√(235/fy0)]
2 = 70(235/355) = 46.34 17.53 < 46.34 ∴PASS di/ti ≤ 70ε2 (Class 1 or 2 for compression brace) 70ε2 = 70 [√(235/fy0)]
2 = 70(235/355) = 46.34 d1/t1 = 139.7/5.0 = 27.94 < 46.34 ∴PASS di/ti ≤ 50 d1/t1 = 139.7/5.0 = 27.94 ∴PASS d2/t2 = 114.3/3.6 = 31.75 ∴PASS 0.2 ≤ di/d0 ≤ 1.0 d1/d0 = 139.7/219.1 = 0.64 ∴PASS d2/d0 = 114.3/219.1 = 0.52 ∴PASS -0.55 d0 ≤ e ≤ +0.25 d0 -0.55 x 219.1 ≤ e ≤ +0.25 x 219.1 -120.5 ≤ e ≤ +54.8 e = -42.2 mm ∴PASS 25% ≤ λov ≤ 100% λov = |g| sin θ i /di x 100% ∴PASS λov = 45 sin 45°/114.3 x 100% λov = 27.8% ∴PASS 30° ≤ θ i ≤ 90° θ1 = 45° ∴PASS θ2 = 45° ∴PASS
Reference
5.1.1 Figure 27
(EN 1993-1-1)
Table 5.2 (EN 1993-1-1)
Table 5.2
Welded Joints Examples CHS Overlap K-Joint
13
Chord face failure (deformation)
Compression brace (1):
5M0
1
1
200ypg
Rd,1 /dd2.108.1
sintfkk
Nfailure, face Chord γ⎟⎟⎠
⎞⎜⎜⎝
⎛+
θ=
Gap/lap function, kg
764.85.122
1.219t2
d
0
0 =×
==γ
Using formulae: Using graph:
( )⎥⎥⎦
⎤
⎢⎢⎣
⎡
−+γ
+γ=33.1t/g5.0exp1
024.01k0
2.12.0
g
Note: g is positive for a gap and negative for an overlap
( )( )⎥⎥⎦
⎤
⎢⎢⎣
⎡
−−×+×
+=33.15.12/455.0exp1
764.8024.01764.8k2.1
2.0g
024.2kg =
from graph; g/t0 = -45/12.5 = -3.6 kg = 2.024
CHS chord end stress factor, kp CHS chord least compressive applied factored stress, σp,Ed;
0,op,el
Ed,0,op
0,ip,el
Ed,0,ip
0
Ed,pEd,p W
M
W
M
AN
++=σ
Note: Moment is additive to compressive stress which is positive for moments. For CHS chords use least compressive chord stress.
22Ed,p N/mm30.123
101.8110001000
=×
×=σ
Chord factored stress ratio, np; 347.0355
30.123f
n0y
Ed,pp =⎟
⎠
⎞⎜⎝
⎛=⎟⎟⎠
⎞⎜⎜⎝
⎛ σ=
Using formulae: Using graph: For np > 0 (compression): kp = 1 - 0.3 np (1 + np) but ≤ 1.0
( ) 0.1but347.01347.03.01kp ≤+×−=
860.0kp =
from graph; kp = 0.860
Reference 5.1.3
6.3
5.1.2.2 5.1.2.1
5.1.2.1
5.1.2.2Fig. 29
5.1.2.1Fig. 28
5.1.2.1
Welded Joints Examples CHS Overlap K-Joint
14
0.1/1.2197.1392.108.1
45sin5.12355860.0024.2N
2
Rd,1 ⎟⎠
⎞⎜⎝
⎛ +°
×××=
kN1134N Rd,1 = Tension brace (2):
Rd,12
1Rd,2 N
sinsin
Nθθ
=
113445sin45sinN Rd,2 ×
°°
=
kN1134N Rd,2 = Chord punching shear check not required for overlapping bracings Localised shear check for overlapping bracings not required as overlap not greater than 60%. Therefore, joint strength dictated by chord face failure for both bracings; PASS kN 500kN1134N,resistance joint 1 Brace Rd,1 ∴>= PASS kN 400kN1134N,resistance joint 2 Brace Rd,2 ∴>=
Reference 5.1.3
Welded Joints Examples RHS Gap K-Joint
4 RHS Gap K-Joint
15
References are generally to Tata Steel publication ‘Design of Welded Joints’ (unless otherwise stated).
N1,Ed = 650 kN
SHS 200 x 200 x 10All material Celsius 355 to EN 10210
SHS 120 x 120 x 5
45º
5
45º
N2,Ed = - 650 kN
40
Np,Ed = 1000 kN N0,Ed = 1920 kN
Dimensions b0 = 200 mm b1 = 120 mm b2 = 120 mm h0 = 200 mm h1 = 120 mm h2 = 120 mm t0 = 10.0 mm t1 = 5.0 mm t2 = 5.0 mm
Validity limits check Chord: (b0-3 t0)/t0 ; (h0-3 t0)/t0 ≤ 38ε (Class 1 or 2 compression) 38ε = 38 √(235/fy0) = 38√(235/355) = 30.92 (b0-3 t0)/t0 = (200-3 x 10)/10 = 17 ∴PASS (h0-3 t0)/t0 = (200-3 x 10)/10 = 17 ∴PASS b0/t0 ≤ 35 b0/t0 = 200/10 = 20 ∴PASS h0/t0 ≤ 35 h0/t0 = 200/10 = 20 ∴PASS Compression brace: bi/ti ; hi/ti ≤ 35 b1/t1 = 120/5 =24 ∴PASS h1/t1 = 120/5 =24 ∴PASS Compression brace: (b1-3 t1)/t1 ; (h1-3 t1)/t1 ≤ 38ε (Class 1 or 2 compression) 38ε = 38 √(235/fy0) = 38√(235/355) = 30.92 (b1-3 t1)/t1 = (120-3 x 5)/5 = 21 ∴PASS (h1-3 t1)/t1 = (120-3 x 5)/5 = 21 ∴PASS Tension brace: bi/ti ; hi/ti ≤ 35 b2/t2 = 120/5 =24 ∴PASS h2/t2 = 120/5 =24 ∴PASS bi/b0 ≥ 0.35 b1/b0 = 120/200 = 0.6 ∴PASS b2/b0 = 120/200 = 0.6 ∴PASS 0.1+0.01 b0/t0 ≤ bi/b0 ≤ 1.0 0.1+0.01 b0/t0 = 0.3 b1/b0 = 120/200 = 0.6 ∴PASS b2/b0 = 120/200 = 0.6 ∴PASS
Reference
5.3.1 Figure 37 (EN 1993-1-1)
Table 5.2
(EN 1993-1-1)
Table 5.2
Welded Joints Examples RHS Gap K-Joint
16
0.5 ≤ h0/b0 ≤ 2.0 h0/b0 = 200/200 = 1.0 ∴PASS 0.5 ≤ hi/bi ≤ 2.0 h1/b1 = 120/120 = 1.0 ∴PASS h2/b2 = 120/120 = 1.0 ∴PASS -0.55 h0 ≤ e ≤ +0.25 h0 -0.55 x 200 ≤ e ≤ +0.25 x 200 -110.0 ≤ e ≤ +50.0 e = +5.0 mm ∴PASS 30° ≤ θ i ≤ 90° θ 1 = 45° ∴PASS θ 2 = 45° ∴PASS g ≥ t1 + t2 40 ≥ 5 + 5 = 10 mm ∴PASS 0.5 b0(1-β) ≤ g ≤ 1.5 b0(1-β) g = 40 mm β = (b1+b2+h1+h2)/(4 b0) β = (120+120+120+120)/(4x200) = 0.6 0.5 x 200(1-0.6) ≤ g ≤ 1.5 x 200(1-0.6) 40 mm ≤ g ≤ 120 mm ∴PASS -0.55 h0 ≤ e ≤ +0.25 h0 e = 5 mm -0.55 x 200 ≤ e ≤ +0.25 x 200 -110 ≤ e ≤ +50 ∴PASS Chord face failure (deformation) – brace 1 Note: Brace 1 usually designated compression and brace 2 tension. Compression brace (1):
5M0
2121
i
200yn
Rd,i /b4
hhbbsin
tfk9.8N γ⎟⎟
⎠
⎞⎜⎜⎝
⎛ +++θ
γ=
Reference
5.3.3 5.3.3
Welded Joints Examples RHS Gap K-Joint
17
RHS chord end stress factor, kn RHS chord most compressive applied factored stress, σ0,Ed;
0,op,el
Ed,0,op
0,ip,el
Ed,0,ip
0
Ed,0Ed,0 W
M
W
M
AN
++=σ
Note: Moment is additive to compressive stress which is positive for moments. For RHS chords use most compressive chord stress.
22Ed,0 N/mm34.256
109.7410001920
=×
×=σ
Chord factored stress ratio, n;
⎟⎠
⎞⎜⎝
⎛=⎟
⎟⎠
⎞⎜⎜⎝
⎛ σ=
35534.256
fn
0y
Ed,0
722.0n =
Using formulae: Using graph: For n > 0 (compression):
β−=
n4.03.1kn but kn ≤ 1.0
0.1but6.0
722.04.03.1kn ≤×
−=
819.0kn =
From graph, for β = 0.6; kn = 0.819
10102
200t2
b
0
0 =×
==γ
0.1/2004
12012012012045sin
1010355819.09.8N2
Rd,1 ⎥⎦
⎤⎢⎣
⎡×
+++×
°××××
=
kN694N Rd,1 =
Reference 5.3.2.1
5.3.2.1
6.3
5.3.2.1Fig. 38
5.3.2.1
Welded Joints Examples RHS Gap K-Joint
18
Chord shear between bracings check – brace 1
5Mi
0,v0yRd,i /
sin3
AfN γ
θ=
where: for RHS bracings:
212.0
1034041
1
t3
g41
1
2
2
20
2=
×
×+
=
+
=α
Av,0 = (2 h0 + α b0) t0 ( ) 2
0,v mm 442410200212.02002A =×+×=
0.1/45sin3
4424355N Rd,i°
×=
kN1282N Rd,1 = Bracing Effective width – brace 1 ( ) 5MeffiiiiyiRd,i /bbt4h2tfN γ++−= where:
ii,effiiyi
00y
0
0i,eff bbbutb
tftf
bt10b ≤×=
mm 120bbutmm 1201205355
10355200
1010b i,effi,eff ≤=×××
××
=
beff,i = 120 mm ( ) 0.1/1201205412025355N Rd,i ++×−××= kN817N Rd,1 =
Reference 5.3.3 5.3.2.5 5.3.2.5 5.3.3
5.3.2.2
Welded Joints Examples RHS Gap K-Joint
19
Chord punching shear – brace 1 (valid when β ≤ 1 – 1/γ) β ≤ 1 – 1/γ
0.6 ≤ 1 – 1/10 = 0.9 mm ∴check chord punching shear
5Mi,p,eii
i
i
00yRd,i /bb
sinh2
sin3
tfN γ⎟⎟
⎠
⎞⎜⎜⎝
⎛++
θθ=
where:
ii,p,ei0
0i,p,e bbbutb
bt10b ≤=
mm 120bbutmm 60120200
1010b i,p,ei,p,e ≤=××
=
be,p,i = 60 mm
0.1/6012045sin1202
45sin310355N Rd,i ⎟⎟
⎠
⎞⎜⎜⎝
⎛++
°×
°
×=
kN1506N Rd,1 = Summary - brace 1 Joint strength for brace 1 dictated by chord face deformation. ∴ Brace 1 joint resistance, PASS kN 650kN694N Rd,1 ∴>= Brace 2 Repeat brace resistance formulae for brace 2. Note: As both braces are of same geometry, brace 2 resistance will be the same: Chord face deformation, kN694N Rd,2 = Chord shear check, kN1282N Rd,2 = Bracing effective width, kN817N Rd,2 = Punching shear, kN1506N Rd,2 = ∴ Brace 2 joint resistance, PASS kN 650kN694N Rd,2 ∴>=
Reference 5.3.3 5.3.3
5.3.2.2
Welded Joints Examples RHS Gap K-Joint
20
Chord axial load resistance in gap Check: N0,gap,Rd ≥ N0,gap,Ed
( ) ( ) 5M2
Rd,0,plEd,00y0,v0y0,v0Rd,gap,0 /V/V1fAfAAN γ⎥⎦⎤
⎢⎣⎡ −+−=
where: A0 = 74.9 cm2 = 7490 mm2 Av,0 = 4424 mm2 V0,Ed = max( |N1,Ed| sin θ1 , |N2,Ed| sin θ2) V0,Ed = max( |650| sin 45° , |-650| sin 45°) = max (459.6, 459.6) V0,Ed = 459.6 kN
0M
0y0,vRd,0,pl
)3/f(AV
γ=
kN 7.9060.1
)3/355(4424V Rd,0,pl =×
=
650 - 650
Np,Ed = 1000 1000 460
460N0,Ed = 1920
1000 460
N0,gap,Ed = 1460
460 Horz 460 Horz
Change of chord axial force in K-joint N0,gap,Ed = max (Np,Ed + N1,Ed cos θ1, N0,Ed + N2,Ed cos θ2) N0,gap,Ed = max (1000 + 650 cos 45°, 1920 + (-650) cos 45°) N0,gap,Ed = max (1460, 1460) = 1460 kN
( ) ( ) 0.1/7.906/6.4591355442435544247490N 2Rd,gap,0 ⎥⎦
⎤⎢⎣⎡ −×+−=
PASS kN 1460kN2442N Rd,gap,0 ∴>=
Reference 5.3.3 5.3.3 5.3.2.5 5.3.3 5.3.3 (EN 1993-1-1)
6.2.6 (2)
5.3.3
Welded Joints Examples RHS Overlap K-Joint
5 RHS Overlap K-Joint
21
References are generally to Tata Steel publication ‘Design of Welded Joints’ (unless otherwise stated).
N1,Ed = 600 kN
Np,Ed = 1000 kN N0,Ed = 1849 kNSHS 200 x 200 x 10All material Celsius 355 to EN 10210
SHS 120 x 120 x 5 N2,Ed = - 600 kN
45º45º 70 i j
-50.1
Dimensions b0 = 200 mm b1 = 120 mm b2 = 120 mm h0 = 200 mm h1 = 120 mm h2 = 120 mm t0 = 10.0 mm t1 = 5.0 mm t2 = 5.0 mm Validity limits check Chord: (b0-3 t0)/t0 ; (h0-3 t0)/t0 ≤ 38ε (Class 1 or 2 compression) 38ε = 38 √(235/fy0) = 38√(235/355) = 30.92 (b0-3 t0)/t0 = (200-3 x 10)/10 = 17 ∴PASS (h0-3 t0)/t0 = (200-3 x 10)/10 = 17 ∴PASS Compression brace: (b1-3 t1)/t1 ; (h1-3 t1)/t1 ≤ 33ε (Class 1 compression) 33ε = 33 √(235/fy0) = 33√(235/355) = 26.85 (b1-3 t1)/t1 = (120-3 x 5)/5 = 21 ∴PASS (h1-3 t1)/t1 = (120-3 x 5)/5 = 21 ∴PASS Tension brace: bi/ti ; hi/ti ≤ 35 b2/t2 = 120/5 =24 ∴PASS h2/t2 = 120/5 =24 ∴PASS 0.25 ≤ bi/b0 ≤ 1.0 b1/b0 = 120/200 = 0.6 ∴PASS b2/b0 = 120/200 = 0.6 ∴PASS 0.5 ≤ h0/b0 ≤ 2.0 h0/b0 = 200/200 = 1.0 ∴PASS 0.5 ≤ hi/bi ≤ 2.0 h1/b1 = 120/120 = 1.0 ∴PASS h2/b2 = 120/120 = 1.0 ∴PASS -0.55 h0 ≤ e ≤ +0.25 h0 -0.55 x 200 ≤ e ≤ +0.25 x 200 -110.0 ≤ e ≤ +50.0 e = -50.1 mm ∴PASS 25% ≤ λ ov λ ov = |g| sin θ i /h i x 100% λ ov = 70 sin 45°/120 x 100% λ ov = 41.2% ∴PASS bi/bj ≥ 0.75 bi/bj = 120/120 = 1.0 ∴PASS
Reference
5.3.1 Figure 37 (EN 1993-1-1)
Table 5.2
(EN 1993-1-1) Table 5.2
Welded Joints Examples RHS Overlap K-Joint
22
Bracing Effective width – Overlapping brace, i (2)
Note: Only the overlapping brace (i) need be checked. The resistance of the overlapped brace (j) is based on an efficiency ratio to that of the overlapping brace. Overlapping brace, i (2): For 25% ≤ λov < 50%
5Miov
iov,ei,effiyiRd,i /t450
h2bbtfN γ⎟⎠
⎞⎜⎝
⎛ −λ
++=
where:
ii,effiiyi
00y
0
0i,eff bbbutb
tftf
bt10b ≤×=
mm 120bbutmm 1201205355
10355200
1010b i,effi,eff ≤=×××
××
=
beff,i = 120 mm
iov,eiiyi
jyj
j
jov,e bbbutb
tftf
bt10
b ≤×=
120bbut12053555355
120510b ov,eov,e ≤×
××
××
=
mm 50b ov,e =
0.1/5450
2.411202501205355N Rd,i ⎟⎠
⎞⎜⎝
⎛ ×−×++×=
PASS kN 600kN617NN Rd,2Rd,i ∴>== Bracing Effective width – Overlapped brace, j (1)
( )( )yii
yjjRd,iRd,j fA
fANN =
where: Aj = A1 = 22.7 cm2 = 2270 mm2 Ai = A2 = 22.7 cm2 = 2270 mm2
( )( )3552270
3552270617N Rd,j ××
×=
PASS kN 600kN617NN Rd,1Rd,i ∴>==
Reference 5.3.3
5.3.3
5.3.2.2
5.3.2.2
5.3.3
Welded Joints Examples RHS Chord CHS Bracings Gap K-Joint
6 RHS Chord CHS Bracings Gap K-Joint
23
References are generally to Tata Steel publication ‘Design of Welded Joints’ (unless otherwise stated).
Dimensions b0 = 200 mm d1 = 114.3 mm d2 = 114.3 mm h0 = 200 mm t1 = 6.3 mm t2 = 6.3 mm t0 = 10.0 mm
Validity limits check Chord: (b0-3 t0)/t0 ; (h0-3 t0)/t0 ≤ 38ε (Class 1 or 2 compression) 38ε = 38 √(235/fy0) = 38√(235/355) = 30.92 (b0-3 t0)/t0 = (200-3 x 10)/10 = 17 ∴PASS (h0-3 t0)/t0 = (200-3 x 10)/10 = 17 ∴PASS b0/t0 ≤ 35 b0/t0 = 200/10 = 20 ∴PASS h0/t0 ≤ 35 h0/t0 = 200/10 = 20 ∴PASS
Compression brace: (d1/t1 ≤ 50ε (Class 1 or 2 compression) 50ε = 50 √(235/fy0) = 50√(235/355) = 40.7 d1/t1 = 114.3/6.3 = 18.1 ≤ 40.7 ∴PASS Tension brace: di/ti ≤ 50 d2/t2 = 114.3/6.3 = 18.1 ∴PASS 0.4 ≤ di/b0 ≤ 0.8 d1/b0 = 114.3/200 = 0.57 ∴PASS d2/b0 = 114.3/200 = 0.57 ∴PASS
Reference
5.3.1 Figure 37 (EN 1993-1-1)
Table 5.2
(EN 1993-1-1)
Table 5.2
g = 85
45° 45°
Np,Ed = 1212 kN
N2,Ed = - 500 kN
N1,Ed = 500 kN
N0,Ed = 1920 kN
CHS 114.3 x 6.3
SHS 200 x 200 x 10
ALL MATERIAL; CELSIUS 355 to EN 10210
e = 23.3
Welded Joints Examples RHS Chord CHS Bracings Gap K-Joint
24
0.5 ≤ h0/b0 ≤ 2.0 h0/b0 = 200/200 = 1.0 ∴PASS
-0.55 h0 ≤ e ≤ +0.25 h0 -0.55 x 200 ≤ e ≤ +0.25 x 200 -110.0 ≤ e ≤ +50.0 e = +23.0 mm ∴PASS 30° ≤ θ i ≤ 90° θ 1 = 45° ∴PASS θ 2 = 45° ∴PASS g ≥ t1 + t2 85 ≥ 6.3 + 6.3 = 12.6 mm ∴PASS
Chord face failure (deformation) – brace 1 Note: Brace 1 usually designated compression and brace 2 tension. Compression brace (1):
5M0
2121
i
200yn
Rd,i /b4
ddddsin
tfk9.8N γ⎟⎟
⎠
⎞⎜⎜⎝
⎛ +++θ
γ=
RHS chord end stress factor, kn RHS chord most compressive applied factored stress, σ0,Ed;
0,op,el
Ed,0,op
0,ip,el
Ed,0,ip
0
Ed,0Ed,0 W
M
W
M
AN
++=σ
Note: Moment is additive to compressive stress which is positive for moments. For RHS chords use most compressive chord stress.
22Ed,0 N/mm34.256
109.7410001920
=×
×=σ
Chord factored stress ratio, n;
⎟⎠
⎞⎜⎝
⎛=⎟
⎟⎠
⎞⎜⎜⎝
⎛ σ=
35534.256
fn
0y
Ed,0
722.0n =
Reference
5.3.3
5.3.2.1
5.3.2.1
Welded Joints Examples RHS Chord CHS Bracings Gap K-Joint
25
Using formulae: Using graph: For n > 0 (compression):
β−=
n4.03.1kn but kn ≤ 1.0
0.1but6.0
722.04.03.1kn ≤×
−=
819.0kn =
From graph, for β = 0.6; kn = 0.819
10102
200t2
b
0
0 =×
==γ
0.1/2004
3.1143.1143.1143.11445sin
1010355819.09.8N2
Rd,1 ⎥⎦
⎤⎢⎣
⎡×
+++×
°××××
=
kN5194
661......kN661N Rd,1 =π
×=
Chord shear between bracings check – brace 1
5Mi
0,v0yRd,i /
sin3
AfN γ
θ=
where: for CHS bracings: 0=α Av,0 = (2 h0 + α b0) t0 ( ) 2
0,v mm 40001020002002A =×+×=
0.1/45sin3
4000355N Rd,i°
×=
kN9104
......kN1159N Rd,1 =π
×=
Reference
6.3
5.3.3
5.3.2.5
5.3.2.5
5.3.2.1Fig. 38
5.3.2.1
Welded Joints Examples RHS Chord CHS Bracings Gap K-Joint
26
Bracing Effective width – brace 1 ( ) 5MeffiiiiyiRd,i /bdt4d2tfN γ++−= where:
ii,effiiyi
00y
0
0i,eff dbbutd
tftf
bt10b ≤×=
mm 120bbutmm 2.951203.6355
10355200
1010b i,effi,eff ≤=×××
××
=
beff,i = 95.2 mm ( ) 0.1/2.953.1143.643.11423.6355N Rd,i ++×−××=
kN7254
.....kN923N Rd,1 =π
×=
Chord punching shear – brace 1 (valid when β ≤ 1 – 1/γ) β ≤ 1 – 1/γ
0.6 ≤ 1 – 1/10 = 0.9 mm ∴check chord punching shear
5Mi,p,eii
i
i
00yRd,i /bd
sind2
sin3
tfN γ⎟⎟
⎠
⎞⎜⎜⎝
⎛++
θθ=
where:
ii,p,ei0
0i,p,e dbbutd
bt10b ≤=
mm 120bbutmm 2.573.114200
1010b i,p,ei,p,e ≤=××
=
be,p,i = 57.2 mm
0.1/2.573.11445sin
3.114245sin310355N Rd,i ⎟⎟
⎠
⎞⎜⎜⎝
⎛++
°×
°
×=
kN11264
........kN1434N Rd,1 =π
×=
Summary - brace 1 Joint strength for brace 1 dictated by chord face deformation. ∴ Brace 1 joint resistance, PASS kN 500kN519N Rd,1 ∴>=
Reference 5.3.3
5.3.2.2
5.3.3
5.3.3 5.3.2.2
Welded Joints Examples RHS Chord CHS Bracings Gap K-Joint
27
Brace 2 Repeat brace resistance formulae for brace 2. Note: As both braces are of same geometry, brace 2 resistance will be the same: Chord face deformation, kN519N Rd,2 = Chord shear check, kN910N Rd,2 = Bracing effective width, kN725N Rd,2 = Punching shear, kN1126N Rd,2 = ∴ Brace 2 joint resistance, PASS kN 500kN519N Rd,2 ∴>= Chord axial load resistance in gap Check: N0,gap,Rd ≥ N0,gap,Ed
( ) ( ) 5M2
Rd,0,plEd,00y0,v0y0,v0Rd,gap,0 /V/V1fAfAAN γ⎥⎦⎤
⎢⎣⎡ −+−=
where: A0 = 74.9 cm2 = 7490 mm2 Av,0 = 4000 mm2 V0,Ed = max( |N1,Ed| sin θ1 , |N2,Ed| sin θ2) V0,Ed = max( |500| sin 45° , |-500| sin 45°) = max (354,354 ) V0,Ed = 354 kN
0M
0y0,vRd,0,pl
)3/f(AV
γ=
kN 8.8190.1
)3/355(4000V Rd,0,pl =×
=
Reference 5.3.3 5.3.2.5 5.3.3
5.3.2.2 5.3.3 (EN 1993-1-1)
6.2.6 (2)
Welded Joints Examples RHS Chord CHS Bracings Gap K-Joint
28
500 - 500
Np,Ed = 1212 1212 354
354N0,Ed = 1920
1212 354
N0,gap,Ed = 1566
354 Horz 354 Horz
Change of chord axial force in K-joint N0,gap,Ed = max (Np,Ed + N1,Ed cos θ1, N0,Ed + N2,Ed cos θ2) N0,gap,Ed = max (1212 + 500 cos 45°, 1920 + (-500) cos 45°) N0,gap,Ed = max (1566, 1566) = 1566 kN
( ) ( ) 0.1/8.819/3541355400035540007490N 2Rd,gap,0 ⎥⎦
⎤⎢⎣⎡ −×+−=
PASS kN 1566kN2520N Rd,gap,0 ∴>=
Reference 5.3.3
Welded Joints Examples RHS Chord CHS Bracings Overlap K-Joint 82.7
7 RHS Chord CHS Bracings Overlap K-Joint 82.7
29
References are generally to Tata Steel publication ‘Design of Welded Joints’ (unless otherwise stated).
NOTE: BRACE ‘j’ USUALLY DESIGNATED COMPRESSION AND BRACE ‘i’ TENSION.
Dimensions
h0 = 100.0 mm b0 = 200.0 mm di = 114.3 mm dj = 114.3 mm t0 = 10.0 mm ti = 6.3 mm tj = 6.3 mm fu,i = 470 N/mm²
fu,j = 470 N/mm² (fu,i & fu,j from EN10210-1:2006 Table A.3) For Eccentricity;
( ) 2h
sinsinsin
gsin2d
sin2de 0
ji
ji
j
j
i
i −⎥⎥⎦
⎤
⎢⎢⎣
⎡
θ+θ
θ×θ×⎥⎥⎦
⎤
⎢⎢⎣
⎡+
θ×+
θ×=
( )mm1.109g
60sin1003.1147.82g
sin100dgwhere
i
iov
−=°×
×=
θ××λ
=
Reference
6.5 Figure 57
30° 60°e = - 19.5
CHS 114.3 x 6.3
CHS 114.3 x 6.3
Ni,Ed = - 400kN
Nj,Ed = 500kN
Np,Ed = 1000kN N0,Ed = 1636kN
RHS 200 x 100 x 10
ALL MATERIAL; CELSIUS 355 to EN 10210
-109.1
Welded Joints Examples RHS Chord CHS Bracings Overlap K-Joint 82.7
30
( ) ( ) ( ) ( ) ( )( )
mm5.19e
2100
3060sin30sin60sin1.109
30sin23.114
60sin23.114e
−=
−⎥⎦
⎤⎢⎣
⎡°+°°×°
×⎥⎦
⎤⎢⎣
⎡−+
°×+
°×=
Validity limits check
b0/t0 ≤ 38ε2 (Class 1 or 2 for compression chord) 38ε2 = 38 [√(235/fy0)]
2 = 38(235/355) = 25.15 b0/t0 = 200.0/10.0 = 20.0 < 25.15 ∴PASS
dj/tj ≤ 50ε2 (Class 1 for compression brace) 50ε2 = 50 [√(235/fy0)]
2 = 50(235/355) = 33.10 dj/tj = 114.3/6.3 = 18.14 < 33.10 ∴PASS di/ti ≤ 50 (Tension Brace) di/ti = 114.3/6.3 = 18.14 ≤ 50 ∴PASS 0.4 ≤ di/b0 ≤ 0.8 di/d0 = 114.3/200.0 = 0.57 ∴PASS dj/d0 = 114.3/200.0 = 0.57 ∴PASS 0.5 ≤ h0/ b0 ≤ 2.0 h0/ b0 = 100.0/200.0 = 0.50 ∴PASS -0.55 h0 ≤ e ≤ +0.25 h0 -0.55 x 100.0 ≤ e ≤ +0.25 x 100.0 -55 ≤ e ≤ +25 e = -19.5 mm ∴PASS λov ≥ 25% λov = |g| sin θ I /di x 100% ∴PASS λov = 109.1 sin 60°/114.3 x 100% λov = 82.7% ∴PASS 30° ≤ θI ≤ 90° θj = 30° ∴PASS θI = 60° ∴PASS di/dj ≥ 0.75 di/dj = 114.3/114.3 = 1.0 ∴PASS
Brace Effective Width;
Overlapping brace (i):
( ) 5Miiov,eiiyiRd,i /t4d2ddtfN γ−++=
where:
iov,eiiyi
jyj
jjov,e ddbutd
tftf
t/d10d ≤×
×
××=
Reference
(EN1993-1-1) (Table 5.2)
(EN1993-1-1) (Table 5.2)
5.3 Figure 37
5.3.3
5.3.2.2
Welded Joints Examples RHS Chord CHS Bracings Overlap K-Joint 82.7
31
mm63d3.114but63d
3.114dbut3.1143.63553.6355
3.6/3.11410d
ov,eov,e
ov,eov,e
=∴≤=
≤×××
×=
∴ Ni,Rd = 355 x 6.3 x (114.3 + 63 + 228.6 – 25.2) / 1.0
=Rd,iN 851 kN ----- 851 × π⁄4 = 668 kN > 400 kN ∴ PASS
Brace Effective Width;
Overlapped Brace (j):
( )( )yii
yjjRd,iRd,j fA
fANN
×
××=
where:
22
i
22j
mm2140cm4.21A
mm2140cm4.21A
==
==
( )( )3552140
3552140668N Rd,j ××
×=
PASSkN500kN668N Rd,j ∴>=
Overlapping Bracings Shear Check For CHS Bracings;
.weldingneedstoehidden%20componentverticalbracebetweendifferenceAs
%8.271004.3462504.346.diffcomponent.vert%
kN250)30(sin500NkN4.346)60(sin400N
)(sinNN&)(sinNN
;N&NofcomponentVertical
Ed,v,j
Ed,v,i
jEd,jEd,v,jiEd,iEd,v,i
Ed,jEd,i
>∴
=×−
=∴
=°×=∴
=°×=∴
θ×=θ×=∴
Reference
5.3.3
Welded Joints Examples RHS Chord CHS Bracings Overlap K-Joint 82.7
32
Shear Check valid when 80% < λov < 100% and overlapped brace hidden toe welded;
( )5Mj
jj,effsjj,u
i
ii,effiov
i,u
jEd,jiEd,i
1sin
tdcd2
3
f
sin
tdd2100
100
3
f4
......
...........cosNcosN
γ×
⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢
⎣
⎡
θ
××+×+
θ
×⎥⎥⎦
⎤
⎢⎢⎣
⎡⎜⎜⎝
⎛+×⎟
⎠
⎞λ−
××π
≤θ+θ
mm4.91d3.1144.91d
3.114but3.1143.6355
10355200
1010d
dbutdtftf
bt10d:where
i,effi,eff
i,eff
iiii,y
00,y
0
0i,eff
=∴≤=
≤×××
××
=
≤××
××=
mm4.91d3.1144.91d
3.114but3.1143.6355
10355200
1010d
dbutdtftf
bt10d:where
j,effj,eff
j,eff
jjjj,y
00,y
0
0j,eff
=∴≤=
≤×××
××
=
≤××
××=
)weldedtoehidden(2c:where s=
( )
( )( )( )
( ) 11
30sin3.64.9123.1142
3470
60sin
3.64.913.1142100
7.82100
3470
4......
...........cosNcosN jjii
×
⎥⎥⎥⎥⎥⎥
⎦
⎤
⎢⎢⎢⎢⎢⎢
⎣
⎡
°××+×
×+°
×⎥⎥⎦
⎤
⎢⎢⎣
⎡⎜⎜⎝
⎛+××⎟⎟
⎠
⎞−
××π
≤θ+θ∴
= 1307 kN
∴ ( ) ( ) PASSkN1307kN63330cos50060cos400 ∴≤=°×+°×
Reference
5.3.3
5.3.2.2
5.3.2.2
5.1.3
Welded Joints Examples RHS Chord CHS Bracings Overlap K-Joint 102.7
8 RHS Chord CHS Bracings Overlap K-Joint 102.7
33
References are generally to Tata Steel publication ‘Design of Welded Joints’ (unless otherwise stated).
NOTE: BRACE ‘j’ USUALLY DESIGNATED COMPRESSION AND BRACE ‘i’ TENSION.
Dimensions
h0 = 100.0 mm b0 = 200.0 mm di = 114.3 mm dj = 114.3 mm t0 = 10.0 mm ti = 6.3 mm tj = 6.3 mm fu,i = 470 N/mm²
fu,j = 470 N/mm² (fu,i & fu,j from EN10210-1:2006 Table A.3) For Eccentricity;
( ) 2h
sinsinsin
gsin2d
sin2de 0
ji
ji
j
j
i
i −⎥⎥⎦
⎤
⎢⎢⎣
⎡
θ+θ
θ×θ×
⎥⎥⎦
⎤
⎢⎢⎣
⎡+
θ×+
θ×=
( )mm5.135g
60sin1003.1147.102g
sin100dgwhere
i
iov
−=°×
×=
θ××λ
=
Reference
6.5 Figure 57
30° 60°e = - 30.6
CHS 114.3 x 6.3
CHS 114.3 x 6.3
Ni,Ed = - 400kN
Nj,Ed = 500kN
Np,Ed = 1000kN N0,Ed = 1636kN
RHS 200 x 100 x 10
ALL MATERIAL; CELSIUS 355 to EN 10210
g = -135.5
Welded Joints Examples RHS Chord CHS Bracings Overlap K-Joint 102.7
34
( ) ( ) ( ) ( ) ( )( )
mm6.30e
2100
3060sin30sin60sin5.135
30sin23.114
60sin23.114e
−=
−⎥⎦
⎤⎢⎣
⎡°+°°×°
×⎥⎦
⎤⎢⎣
⎡−+
°×+
°×=
Validity limits check
b0/t0 ≤ 38ε2 (Class 1 or 2 for compression chord) 38ε2 = 38 [√(235/fy0)]
2 = 38(235/355) = 25.15 b0/t0 = 200.0/10.0 = 20.0 < 25.15 ∴PASS dj/tj ≤ 50ε2 (Class 1 for compression brace) 50ε2 = 50 [√(235/fy0)]
2 = 50(235/355) = 33.10 dj/tj = 114.3/6.3 = 18.14 < 33.10 ∴PASS di/ti ≤ 50 (Tension Brace) di/ti = 114.3/6.3 = 18.14 ≤ 50 ∴PASS 0.4 ≤ di/b0 ≤ 0.8 di/d0 = 114.3/200.0 = 0.57 ∴PASS dj/d0 = 114.3/200.0 = 0.57 ∴PASS 0.5 ≤ h0/ b0 ≤ 2.0 h0/ b0 = 100.0/200.0 = 0.50 ∴PASS -0.55 h0 ≤ e ≤ +0.25 h0 -0.55 x 100.0 ≤ e ≤ +0.25 x 100.0 -55 ≤ e ≤ +25 e = -30.6 mm ∴PASS λov ≥ 25% λov = |g| sin θ i /di x 100% ∴PASS λov = 135.5 sin 60°/114.3 x 100% λov = 102.7% ∴PASS 30° ≤ θi ≤ 90° θj = 30° ∴PASS θi = 60° ∴PASS di/dj ≥ 0.75 di/dj = 114.3/114.3 = 1.0 ∴PASS
Brace Effective Width;
Overlapping brace (i):
( ) 5Miiov,eiiyiRd,i /t4d2ddtfN γ−++= where λov ≥ 80%;
where:
mm63d3.114but63d
3.114dbut3.1143.63553.6355
3.6/3.11410d
ddbutdtftf
t/d10d
ov,eov,e
ov,eov,e
iov,eiiyi
jyj
jjov,e
=∴≤=
≤×××
×=
≤××
××=
Reference
(EN1993-1-1) Table 5.2
(EN1993-1-1) Table 5.2
5.3 Figure 37
5.3.3
5.3.2.2
Welded Joints Examples RHS Chord CHS Bracings Overlap K-Joint 102.7
35
Ni,Rd = 355 x 6.3 x (114.3 + 63 + 228.6 – 25.2) / 1.0
=Rd,iN 851 kN -------> 851 × π⁄4 = 668 kN > 400 kN ∴ PASS
Brace Effective Width;
Overlapped Brace (j):
( )( )yii
yjjRd,iRd,j fA
fANN
×
××=
where:
22
i
22j
mm2140cm4.21A
mm2140cm4.21A
==
==
( )( )3552140
3552140668N Rd,j ××
×=
PASSkN500kN668N Rd,j ∴>=
Overlapping Bracings Shear Check for CHS Bracings; where λov > 100%;
where:
∴
Reference
5.3.3
5.3.3
5.3.2.2
mm4.91d3.1144.91d
3.114but3.1143.6355
10355200
1010d
dbutdtftf
bt10d
j,effj,eff
j,eff
jjjj,y
00,y
0
0j,eff
=∴≤=
≤×××
××
=
≤××
××=
( )5M
jEd,jiEd,i
1)30sin(
3.64.913.11433
4704
......
...........cosNcosN
γ×
×+×××
π
≤θ+θ
( )5Mj
jj,effjj,u
jEd,jiEd,i
1sin
tdd3
3
f4
......
...........cosNcosN
γ×
θ
×+×××
π
≤θ+θ
kN673cosNcosN jjii ≤θ+θ
( ) ( ) PASSkN673kN63330cos50060cos400 ∴≤=°×+°×
Welded Joints Examples RHS Chord RHS Bracings Overlap KT-Joint
9 RHS Chord RHS Bracings Overlap KT-Joint
36
References are generally to Tata Steel publication ‘Design of Welded Joints’ (unless otherwise stated).
NOTE: Brace ‘j’ designated overlapped, Brace ‘i’ overlapping Brace ‘1’ SHS is 90 x 90 x 5.0, Brace ‘2’ and ‘3’ is SHS 100 x 100 x 6.3 Dimensions
h0 = 200.0 mm h1 = 90.0 mm h2 = 100.0 mm h3 = 100.0 mm b0 = 200.0 mm b1 = 90.0 mm b2 = 100.0 mm b3 = 100.0 mm t0 = 10.0 mm t1 = 5.0 mm t2 = 6.3 mm t3 = 6.3 mm γM5 = 1.0 A1 = 23.2cm2 A2 = 16.7cm2 A3 = 23.2cm2
This example is to show how to calculate a KT-Joint with SHS chord and braces. The method of checking a KT-Joint depends on the direction of the brace forces, gap or overlap and chord section profile. This example is for;
• One diagonal brace opposite direction to the other two bracings • Both diagonal bracings overlapping • Rectangular chord and bracings
With this configuration, the joint can be checked like two separate K-joints. Please be aware that different brace angle and overlap values may change how the joint is calculated and you should refer to the Tata Design of Welded Joints literature before tackling any joint to make sure you are using the correct method and formulae.The force combination of the braces can be seen at 5.6.2 Figure 51(c) (as a (from left to right) compression-compression-tension) of our Design Of Welded Joints literature.
Reference
45° 50°
e = - 19.5
N2,Ed = - 650kN N1,Ed = 492kN
RHS 200 x 100 x 10
ALL MATERIAL; CELSIUS 355 to EN 10210 N3,Ed = 150kN
SHS 200 x 200 x 10.0
Brace 1
Brace 3
Brace 2
e2= -40.4
e1 = -50.0
Welded Joints Examples RHS Chord RHS Bracings Overlap KT-Joint
37
GEOMETRIC CALCULATIONS For Eccentricity; Brace 1 in relation to Brace 3;
( ) 2h
sinsinsing
sin2b
sin2be 0
31
31
3
3
1
11 −⎥
⎦
⎤⎢⎣
⎡
θ+θθ×θ
×⎥⎦
⎤⎢⎣
⎡+
θ×+
θ×=
Brace 1 to 3 overlap, λov = 50%;
where;
i
iovsin100
bgθ×
×λ=
( ) 145sin100
0.900.50g1 −×°×
×=
mm6.63g1 −= (gap is negative as it’s an overlap)
( ) ( ) ( ) ( ) ( )( )
mm0.50
20.200
9045sin90sin45sin6.63
90sin20.100
45sin20.90e1
−=
−⎥⎦
⎤⎢⎣
⎡°+°°×°
×⎥⎦
⎤⎢⎣
⎡−+
°×+
°×=
For Eccentricity, Brace 2 in relation to Brace 3;
( ) 2h
sinsinsing
sin2b
sin2be 0
32
32
3
3
2
22 −⎥
⎦
⎤⎢⎣
⎡
θ+θθ×θ
×⎥⎦
⎤⎢⎣
⎡+
θ×+
θ×=
Brace 2 to 3 overlap, λov = 50%; where;
2
2ov2 sin100
bgθ×
×λ=
( )°××
=50sin100
1000.50g2
mm3.65g2 −= (gap is negative as it’s an overlap)
( ) ( ) ( ) ( ) ( )( )
mm4.40
20.200
9050sin90sin50sin3.65
90sin20.100
50sin20.100e2
−=
−⎥⎦
⎤⎢⎣
⎡°+°°×°
×⎥⎦
⎤⎢⎣
⎡−+
°×+
°×=
Validity limits check for both K-Joints
(b0-3 t0)/t0 ; (h0-3 t0)/t0 ≤ 38ε (Class 1 or 2 for chord) 38ε = 38 [√(235/fy0)] = 38√ (235/355) = 30.92 (b0-3 t0)/t0 = (200-3 x 10)/10 = 17 ∴PASS (h0-3 t0)/t0 = (200-3 x 10)/10 = 17 ∴PASS
(b1-3 t1)/t1 ; (h1-3 t1)/t1 ≤ 33ε (Class 1 for compression braces)
Reference
6.5 Figure 57
6.5 Figure 57
5.3 Figure 37
(EN1993-1-1) Table 5.2
(EN1993-1-1) Table 5.2
Welded Joints Examples RHS Chord RHS Bracings Overlap KT-Joint
38
33ε = 33 [√(235/fy0)] = 33√ (235/355) = 26.85 (b1-3 t1)/t1 = (90-3 x 5)/5 = 15 ∴PASS
(h1-3 t1)/t1 = (90-3 x 5)/5 = 15 ∴PASS (b3-3 t3)/t3 = (100-3 x 6.3)/6.3 = 12.9 ∴PASS (h3-3 t3)/t3 = (100-3 x 6.3)/6.3 = 12.9 ∴PASS bi/ti ; hi/ti ≤ 35 (Tension Brace) b2/t2 = 100.0/6.3 = 15.9 ∴PASS h2/t2 = 100.0/6.3 = 15.9 ∴PASS 0.25 ≤ bi/b0 ≤ 1.0 b1/b0 = 90.0/200.0 = 0.45 ∴PASS b2/b0 = 100.0/200.0 = 0.5 ∴PASS b3/b0 = 100.0/200.0 = 0.5 ∴PASS
0.5 ≤ h0/ b0 ≤ 2.0 h0/ b0 = 200.0/200.0 = 1.0 ∴PASS 0.5 ≤ hi/ bi ≤ 2.0 h1/b1 = 90.0/90.0 = 1.0 ∴PASS h2/b2 = 100.0/100.0 = 1.0 ∴PASS h3/b3 = 100.0/100.0 = 1.0 ∴PASS
-0.55 h0 ≤ e ≤ +0.25 h0 -0.55 x 200.0 ≤ e ≤ +0.25 x 200.0 -110 ≤ e ≤ +50 e1 = -50 mm ∴PASS e2 = -40.4 mm ∴PASS
λov ≥ 25% λov,1 = |g| sin θ 1 /h1 x 100%
λov,1 = 63.6 x sin 45°/90 x 100% λov,1 = 50% ∴PASS λov,2 = 65.3 x sin 50°/100 x 100% λov,2 = 50% ∴PASS
30° ≤ θi ≤ 90° θ1 = 45° ∴PASS
θ2 = 50° ∴PASS θ3 = 90° ∴PASS bi/bj ≥ 0.75 b1/b3 = 90.0/100.0 = 0.9 ∴PASS
b2/b3 = 100.0/100.0 = 1.0 ∴PASS Brace 1 & 3 as overlap K-Joint Brace Effective Width Failure for 50% ≤λov<80%;
( ) 5Miiov,ei,effiyiRd,i /t4h2bbtfN γ−++=
where;
11,ov,e111y
33y
3
31,ov,e bbbutb
tftf
bt10b ≤×
×
××=
Reference
6.5 Figure 57
5.3.3 (K- & N-
Overlap Sect)
5.3.2.2
Welded Joints Examples RHS Chord RHS Bracings Overlap KT-Joint
39
mm4.71b0.90but4.71b
0.90bbut0.900.53553.6355
0.1003.610b
1,ov,e1,ov,e
1,ov,e1,ov,e
=∴≤=
≤×××
××
=
where;
11,eff111y
00y
0
01,eff bbbutb
tftf
bt10
b ≤××
××
×=
90bbut900.5355
10355200
1010b 1,eff1,eff ≤×
×
××
×=
mm90b90bbutmm90b 1,eff1,eff1,eff =∴≤=
N1,Rd = 355 x 5.0 x (90.0 + 71.4 + 2 x 90 – 4 x 5.0)/1.0
=Rd,1N 570 kN > 492 kN ∴PASS
For overlapped Brace (3):
where; ( )( )yii
yjjRd,iRd,j fA
fANN
×
××=
22
1
223
mm1670cm7.16A
mm2320cm2.23A
==
==
( )( )3551670
3552320570N Rd,3 ××
×=
=Rd,3N 792kN > 150kN ∴PASS
Brace 2 & 3 as overlap K-Joint
Brace Effective Width Failure for 50% ≤λov<80%;
22,ov,e222y
33y
3
32,ov,e bbbutb
tftf
bt10
b ≤××
××=
Reference
5.3.2.2
5.3.3 (K- & N-
Overlap Sect)
(Tata Technical
Guide TST02)
5.3.2.2
Welded Joints Examples RHS Chord RHS Bracings Overlap KT-Joint
40
mm63b0.100but63b
0.100bbut0.1003.63553.6355
0.1003.610b
2,ov,e2,ov,e
2,ov,e2,ov,e
=∴≤=
≤×××
××
=
where;
22,eff222y
00y
0
02,eff bbbutb
tftf
bt10
b ≤××
××
×=
100bbut100
3.635510355
2001010
b 2,eff2,eff ≤××
××
×=
mm4.79b100bbutmm4.79b 2,eff2,eff2,eff =∴≤=
N2,Rd = 355 x 6.3 x (79.4 + 63 + 2 x 100 – 4 x 6.3) / 1.0
=Rd,2N 709 kN > 650 kN ∴PASS
For Overlapped Brace (3):
where: ( )( )yii
yjjRd,iRd,j fA
fANN
×
××=
22
2
223
mm2320cm2.23A
mm2320cm2.23A
==
==
( )( )3552320
3552320709N Rd,3 ××
×=
N3,Rd = 709kN > 150kN ∴PASS
SUMMARY
Here, the validity limits are combined to include all three braces and then for the calculations, due to the nature of the joint, it can be treated as two overlap K-Joints. This means Brace 3 (the vertical overlapped brace) is checked twice in relation to Brace 1 and Brace 2 and must pass on both of these checks. It is important to check the joint configuration and refer to our Design of Welded Joints literature to make sure the correct method and formulae is used.
Reference
5.3.2.2
5.3.3 (K- & N- Overlap Sect)
(Tata Technical Guide TST02)
Welded Joints Examples CHS Chord CHS Bracings Gap KT-Joint
10 CHS Chord CHS Bracings Gap KT-Joint
41
512kN 1087kN
References are generally to Tata Steel publication ‘Design of Welded Joints’ (unless otherwise stated).
NOTE: Brace ‘1’ CHS is 88.9 x 5.0, Brace ‘2’ and ‘3’ is CHS 101.6 x 6.3 Dimensions
d0 = 193.7 mm d1 = 88.9 mm d2 = 101.6 mm d3 = 101.6 mm t0 = 10.0 mm t1 = 5.0 mm t2 = 6.3 mm t3 = 6.3 mm γM5 = 1.0 A1 = 13.2cm2 A2 = 18.9cm2 A3 = 18.9cm2
This example is to show how to calculate a gap KT-Joint with CHS chord and braces. The recommendations for an all-CHS gap KT-Joint are in EN1993-1-8 Table 7.6. The method of checking a KT-Joint depends on the direction of the brace forces, gap or overlap and chord section profile. This example is for;
• One diagonal brace opposite direction to the other two bracings • Both diagonal bracings have a gap to the central brace • Circular chord and bracings
With this configuration, the joint capacity is based on the most highly loaded compression brace for chord face failure and punching shear failure for each brace. Please be aware that different brace angle and gap values may change how the joint is calculated and you should refer to the Tata Design of Welded Joints literature before tackling any joint to make sure you are using the correct method and formulae.The force combination of the braces can be seen at 5.6.2 Figure 51(c) (as a (from left to right) compression-compression-tension) of our Design Of Welded Joints literature.
Reference
g2,3 = 52mm g1,3 = 30mm
N3,Ed = 113kN
45° 30°
e = - 19.5
N2,Ed = - 488kN
N1,Ed = 369kN
RHS 200 x 100 x 10
ALL MATERIAL; CELSIUS 355 to EN 10210
CHS 193.7 x 10.0
Brace 1
Brace 3
Brace 2
e2 = 21.2mm e1 = 46.8mm
Welded Joints Examples CHS Chord CHS Bracings Gap KT-Joint
42
Geometric Calculations For Eccentricity; Brace 1 in relation to Brace 3;
( ) 2d
sinsinsing
sin2d
sin2de 0
31
31
3
3
1
11 −⎥
⎦
⎤⎢⎣
⎡
θ+θθ×θ
×⎥⎦
⎤⎢⎣
⎡+
θ×+
θ×=
Brace 1 to 3 gap, g1 = 30mm;
( ) ( )( ) ( )( )
mm8.46
27.193
9045sin90sin45sin0.30
90sin26.101
45sin29.88e1
=
−⎥⎦
⎤⎢⎣
⎡°+°°×°
×⎥⎦
⎤⎢⎣
⎡+
°×+
°×=
For Eccentricity, Brace 2 in relation to Brace 3;
( ) 2d
sinsinsing
sin2d
sin2de 0
32
32
3
3
2
22 −⎥
⎦
⎤⎢⎣
⎡
θ+θθ×θ
×⎥⎦
⎤⎢⎣
⎡+
θ×+
θ×=
Brace 2 to 3 gap, g2 = 52mm;
( ) ( )( ) ( )( )
mm2.21
27.193
9030sin90sin30sin0.52
90sin26.101
30sin26.101e2
=
−⎥⎦
⎤⎢⎣
⎡°+°°×°
×⎥⎦
⎤⎢⎣
⎡+
°×+
°×=
Validity limits check for both K-Joints
10 ≤ d0/t0 ≤ 50 d0/t0 = 193.7/10.0 = 19.37 ∴PASS d0/t0 ≤ 70ε2 (Class 1 or 2 for chord) 70ε2 = 70 [√(235/fy0)]2 = 70√ (235/355)2 = 46.34 d0/t0 = 19.37 ≤ 46.34 ∴PASS
di/ti ≤ 50 d1/t1 = 88.9/5.0 = 17.78 ∴PASS d2/t2 = 101.6/6.3 = 16.13 ∴PASS d3/t3 = 101.6/6.3 = 16.13 ∴PASS di/ti ≤ 70ε2 (Class 1 or 2 for compression bracings) 70ε2 = 70 [√(235/fy0)]2 = 70√ (235/355)2 = 46.34 d1/t1= 17.78 ∴PASS d3/t3 = 16.13 ∴PASS 0.2 ≤ di/d0 ≤ 1.0 d1/d0 = 88.9/193.7 = 0.46 ∴PASS d2/d0 = 101.6/193.7 = 0.52 ∴PASS d3/d0 = 101.6/193.7 = 0.52 ∴PASS
-0.55 d0 ≤ e ≤ +0.25 d0 -0.55 x 193.7 ≤ e ≤ +0.25 x 193.7 -106.5 ≤ e ≤ +48.4 e1 = 46.8 mm ∴PASS e2 = 21.2 mm ∴PASS
Reference
5.1.1 Figure 27
(EN1993-1-1)
Table 5.2
(EN1993-1-1) Table 5.2
Welded Joints Examples CHS Chord CHS Bracings Gap KT-Joint
43
g ≥ t1 + t2 but ≤ 12t0 for g1,3 ≥ t1 + t3 = 5.0 + 6.3 = 11.3 mm but ≤ 12t0 g2,3 ≥ t2 + t3 = 6.3 + 6.3 = 12.6 mm but ≤ 12t0
12t0 = 12 x 10.0 = 120 mm g1,3 = 30 mm ∴PASS g2,3 = 52 mm ∴PASS 30° ≤ θi ≤ 90° θ1 = 45° ∴PASS
θ2 = 30° ∴PASS θ3 = 90° ∴PASS
Chord Face Failure (deformation); Based on compression brace with most compressive load; Compression brace (1);
5M0
321
1
200ypg
Rd,1 /d3
ddd2.108.1
sintfkk
N γ⎟⎟⎠
⎞⎜⎜⎝
⎛×
++×+×
θ
×××=
Gap/lap factor, kg;
Using Formulae:
( )⎥⎥⎦
⎤
⎢⎢⎣
⎡
−+γ
+γ=33.1t/g5.0exp1
024.01k0
2.12.0
g
where;
69.90.102
7.193t2
d
0
0 =×
==γ
Note: (g) is positive for gap and negative for overlap. Use the largest gap between two bracings having significant forces acting in opposite direction.
Using Formulae: Using Graph:
( )⎥⎥⎦
⎤
⎢⎢⎣
⎡
−×+×
+=33.10.10/525.0exp1
69.9024.0169.9k2.1
2.0g
70.1kg =
From graph;
g/t0 = 52/10.0 = 5.2
kg = 1.70
Reference
5.1.3 (K- & N- Joints)
5.1.2.2 (kg)
6.3 (γ)
For graph 5.1.2.2 Fig. 29
Welded Joints Examples CHS Chord CHS Bracings Gap KT-Joint
44
PASSkN369kN538N Rd,1 ∴>=
CHS chord end stress factor, kp CHS chord least compressive applied factored stress, σp,Ed;
0,op,el
Ed,0,op
0,ip,el
Ed,0,ip
0
Ed,pEd,p W
M
W
M
AN
++=σ
Note: Moment is additive to compressive stress which is positive for moments. For CHS chords use least compressive chord stress.
22Ed,p N/mm7.88
107.571000512
=×
×=σ
Chord factored stress ratio, np; 25.0355
7.88f
n0y
Ed,pp =⎟
⎠
⎞⎜⎝
⎛=⎟
⎟⎠
⎞⎜⎜⎝
⎛ σ=
Using formulae: Using graph: For np > 0 (compression): kp = 1 - 0.3 np (1 + np) but ≤ 1.0
( ) 0.1but25.0125.03.01kp ≤+×−=
91.0kp =
from graph; kp = 0.91
0.1/7.1933
6.1016.1019.882.108.145sin
0.1035591.070.1N 2
Rd,1 ⎟⎠
⎞⎜⎝
⎛×
++×+×
°×××
=
For this type of configuration (see 5.6.2 Figure 51(c));
1Rd,13Ed,31Ed,1 sinNsinNsinN θ×≤θ×+θ×
°×≤°×+°× 45sin53890sin11345sin369
PASSkN380kN374 ∴≤
Reference
5.1.2.1
5.1.2.1
5.1.2.1 (kp)
For graph 5.1.2.1 Fig. 28
5.6.2
Welded Joints Examples CHS Chord CHS Bracings Gap KT-Joint
45
1Rd,12Ed,2 sinNsinN θ×≤θ×
°×≤°× 45sin53830sin448
PASSkN380kN244 ∴≤
Check for Chord Punching Shear failure;
Valid if: di ≤ d0 – 2t0 where d0 – 2t0 = 193.7 – (2 x 10.0) = 173.7 mm d1 = 88.9 mm d2 = 101.6 mm d3 = 101.6 mm Therefore check for Chord Punching Shear;
5Mi
2i
100y
Rd,i /sin2
sin1dt
3
fN γ
θ×
θ+××π××=
For Brace 1;
0.1/45sin2
45sin19.880.103
355N 2Rd,1
°×
°+××π××=
PASSkN369kN977N Rd,1 ∴>=
For Brace 2;
0.1/30sin2
30sin16.1010.103
355N 2Rd,2
°×
°+××π××=
PASSkN488kN1963N Rd,2 ∴>=
For Brace 3;
0.1/
90sin290sin16.1010.10
3355N
2Rd,3°×
°+××π××=
PASSkN113kN654N Rd,3 ∴>=
Summary Here, the validity limits are combined to include all three braces. The eccentricity values use both brace 1 and 2 (diagonals) in relation to brace 3 (the vertical brace). It is important to check the joint configuration and refer to our Design of Welded Joints literature to make sure the correct method and formulae is used. To re-iterate this is a theoretical method which is not supported by research or tests.
Reference
5.1.3
5.1.3
Welded Joints Examples CHS Chord CHS Bracings Overlap KT-Joint
11 CHS Chord CHS Bracings Overlap KT-Joint
46
512kN 1087kN
References are generally to Tata Steel publication ‘Design of Welded Joints’ (unless otherwise stated).
NOTE: Brace ‘j’ designated overlapped, Brace ‘i’ overlapping Brace ‘1’ CHS is 88.9 x 5.0, Brace ‘2’ and ‘3’ is CHS 101.6 x 6.3 Dimensions
d0 = 193.7 mm d1 = 88.9 mm d2 = 101.6 mm d3 = 101.6 mm t0 = 10.0 mm t1 = 5.0 mm t2 = 6.3 mm t3 = 6.3 mm γM5 = 1.0 A1 = 13.2 cm2 A2 = 18.9 cm2 A3 = 18.9 cm2
fu1 = 470 N/mm2 fu2 = 470 N/mm2 fu3 = 470 N/mm2
This example is to show how to calculate an overlap KT-Joint with CHS chord and braces. Please be aware that there are no recommendations for an overlap KT- Joint in EN1993-1-8 or elsewhere as far as Tata Steel is aware. This is a Tata Steel method and is included in the Tata Steel Design of Welded Joints literature. It is a theoretical method which is not supported by research or tests. The method of checking a KT-Joint depends on the direction of the brace forces, gap or overlap and chord section profile. This example is for;
• One diagonal brace opposite direction to the other two bracings • Both diagonal bracings overlapping • Circular chord and bracings
With this configuration, the joint capacity is based on the most highly loaded compression brace for chord face failure. Please be aware that different overlap values may change how the joint is calculated and you should refer to the Tata Design of Welded Joints literature before tackling any joint to make sure you are using the correct method and formulae.The force combination of the braces can be seen at 5.6.2 Figure 51(c) (as a (from left to right) compression-compression-tension) of our Design Of Welded Joints literature. Due to one of the braces falling within the limits (overlapping percentage) for the localised brace-to-chord shear check, this calculation has also been completed.
Reference
‘fu‘ values taken from Product Standard EN10210-1 Table A.3 as required by UK National Annex
45° 50°
e = - 19.5
N2,Ed = - 488kN N1,Ed = 369kN
RHS 200 x 100 x 10
ALL MATERIAL; CELSIUS 355 to EN 10210 N3,Ed = 113kN
CHS 193.7 x 10.0
Brace 1
Brace 3
Brace 2
e2 = -60.4mm e1 = -73.2mm
Welded Joints Examples CHS Chord CHS Bracings Overlap KT-Joint
47
Geometric Calculations For Eccentricity; Brace 1 in relation to Brace 3;
( ) 2d
sinsinsing
sin2d
sin2de 0
31
31
3
3
1
11 −⎥
⎦
⎤⎢⎣
⎡
θ+θθ×θ
×⎥⎦
⎤⎢⎣
⎡+
θ×+
θ×=
Brace 1 to 3 overlap, λov = 71.6%;
where;
1
1ovsin100
dgθ×
×λ=
( ) 145sin100
9.886.71g1 −×°×
×=
mm90g1 −= (gap is negative as it’s an overlap)
( ) ( ) ( ) ( ) ( )( )
mm2.73
27.193
9045sin90sin45sin0.90
90sin26.101
45sin29.88e1
−=
−⎥⎦
⎤⎢⎣
⎡°+°°×°
×⎥⎦
⎤⎢⎣
⎡−+
°×+
°×=
For Eccentricity, Brace 2 in relation to Brace 3;
( ) 2d
sinsinsing
sin2d
sin2de 0
32
32
3
3
2
22 −⎥
⎦
⎤⎢⎣
⎡
θ+θθ×θ
×⎥⎦
⎤⎢⎣
⎡+
θ×+
θ×=
Brace 2 to 3 overlap, λov = 65.2%; where;
2
2ov2 sin100
dgθ×
×λ=
( )°××
=50sin100
6.1012.65g2
mm5.86g2 −= (gap is negative as it’s an overlap)
( ) ( ) ( ) ( ) ( )( )
mm4.60
27.193
9050sin90sin50sin5.86
90sin26.101
50sin26.101e2
−=
−⎥⎦
⎤⎢⎣
⎡°+°°×°
×⎥⎦
⎤⎢⎣
⎡−+
°×+
°×=
Validity limits check for both K-Joints
10 ≤ d0/t0 ≤ 50 d0/t0 = 193.7/10.0 = 19.37 ∴PASS d0/t0 ≤ 70ε2 (Class 1 or 2 for chord) 70ε2 = 70 [√(235/fy0)]2 = 70√ (235/355)2 = 46.34 d0/t0 = 19.37 ≤ 46.34 ∴PASS
Reference
6.5 Figure 57
6.5 Figure 57
5.1.1 Figure 27
(EN1993-1-1)
Table 5.2
Welded Joints Examples CHS Chord CHS Bracings Overlap KT-Joint
48
di/ti ≤ 50 d1/t1 = 88.9/5.0 = 17.78 ∴PASS d2/t2 = 101.6/6.3 = 16.13 ∴PASS d3/t3 = 101.6/6.3 = 16.13 ∴PASS di/ti ≤ 70ε2 (Class 1 or 2 for compression bracings) 70ε2 = 70 [√(235/fy0)]2 = 70√ (235/355)2 = 46.34 d1/t1= 17.78 ∴PASS d3/t3 = 16.13 ∴PASS 0.2 ≤ di/d0 ≤ 1.0 d1/b0 = 88.9/193.7 = 0.46 ∴PASS d2/b0 = 101.6/193.7 = 0.52 ∴PASS d3/b0 = 101.6/193.7 = 0.52 ∴PASS
-0.55 d0 ≤ e ≤ +0.25 d0 -0.55 x 193.7 ≤ e ≤ +0.25 x 193.7 -106.5 ≤ e ≤ +48.4 e1 = -73.2 mm ∴PASS e2 = -60.4 mm ∴PASS
λov ≥ 25% λov,i = |g| sin θ i /di x 100%
λov,1 = 90.0 x sin 45°/88.9 x 100% λov,1 = 71.6% ∴PASS λov,2 = 86.5 x sin 50°/101.6 x 100% λov,2 = 65.2% ∴PASS
30° ≤ θi ≤ 90° θ1 = 45° ∴PASS
θ2 = 50° ∴PASS θ3 = 90° ∴PASS
Chord Face Failure (deformation); Compression brace (1);
5M0
1
1
200ypg
Rd,1 /dd
2.108.1sin
tfkkN γ⎟⎟
⎠
⎞⎜⎜⎝
⎛×+×
θ
×××=
Gap/lap factor, kg;
Reference
(EN1993-1-1)
Table 5.2
5.1.1 Figure 27 6.5 Figure 57
5.1.3 (K- & N- Joints)
5.1.2.2 (kg)
6.3 (γ)
Using Formulae:
( )⎥⎥⎦
⎤
⎢⎢⎣
⎡
−+γ
+γ=33.1t/g5.0exp1
024.01k0
2.12.0
g
where;
69.90.102
7.193t2
d
0
0 =×
==γ
Note: (g) is positive for gap and negative for overlap
Use the smallest overlap for (g)
Welded Joints Examples CHS Chord CHS Bracings Overlap KT-Joint
49
PASSkN369kN637N Rd,1 ∴>=
PASSkN488kN588N Rd,2 ∴>=
CHS chord end stress factor, kp CHS chord least compressive applied factored stress, σp,Ed;
0,op,el
Ed,0,op
0,ip,el
Ed,0,ip
0
Ed,pEd,p W
M
W
M
AN
++=σ
Note: Moment is additive to compressive stress which is positive for moments. For CHS chords use least compressive chord stress.
22Ed,p N/mm7.88
107.571000512
=×
×=σ
Chord factored stress ratio, np; 25.0355
7.88f
n0y
Ed,pp =⎟
⎠
⎞⎜⎝
⎛=⎟
⎟⎠
⎞⎜⎜⎝
⎛ σ=
Using formulae: Using graph: For np > 0 (compression): kp = 1 - 0.3 np (1 + np) but ≤ 1.0
( ) 0.1but25.0125.03.01kp ≤+×−=
91.0kp =
from graph; kp = 0.91
0.1/7.193
9.882.108.145sin
0.1035591.015.2N 2
Rd,1 ⎟⎠
⎞⎜⎝
⎛ ×+×°
×××=
Tension Brace (2);
Rd,1
2
1Rd,2 N
sinsin
N ×θθ
=
637
50sin45sinN Rd,2 ×
°°
=
Chord Punching shear not required for overlapping bracings
Reference
For graph 5.1.2.2 Fig. 29
5.1.2.1
5.1.2.1
5.1.2.1 (kp)
For graph 5.1.2.1 Fig. 28
5.1.3
Using Formulae: Using Graph:
( )⎥⎥⎦
⎤
⎢⎢⎣
⎡
−−×+×
+=33.10.10/)5.86(5.0exp1
69.9024.0169.9k2.1
2.0g
15.2kg =
From graph;
g/t0 = -86.5/10.0 = -8.7
kg = 2.15
Welded Joints Examples CHS Chord CHS Bracings Overlap KT-Joint
50
Localised Brace-to-Chord Shear Check for overlapped Joints;
Although this failure mode check was included as a corrigendum in section 7.1.2 (6) of EN 1993-1-8, no equations have been included in tables 7.2, 7.10, 7.21 or 7.24. In their absence, the following criteria for adequacy of the shear connection may be used. They are based on research by CIDECT but expressed using EN1993-1-8 symbols.
Modified equation only applicable when brace 3 is the overlapped brace (j) and diagonals 1 and 2 overlap (i).
For KT-Joint overlap joint check 60% < λov,1 or λov,2 < 100%;
( ) .......cosNcosNcosN 3Ed,32Ed,21Ed,1 ≤θ+θ−θ
........sin
tdd2100
100
3
fsin
tdd2100
100
3
f4 2
22,eff22,ov
2u
1
11,eff11,ov
1uθ
×⎥⎥⎦
⎤
⎢⎢⎣
⎡+×⎟⎟
⎠
⎞⎜⎜⎝
⎛ λ−
×+θ
×⎥⎥⎦
⎤
⎢⎢⎣
⎡+×⎟⎟
⎠
⎞⎜⎜⎝
⎛ λ−
×⎜⎜⎝
⎛×
π
( )5M3
33,eff2s3,eff1s3u 1sin
tdcdc
3
fγ
×⎟⎟⎠
⎞
θ
××+××+
where Brace Effective Width (overlapping braces);
ii,effiiyi
00y
0
0i,eff ddbutd
tftf
dt12
d ≤××
××=
9.88dbut9.88
0.53550.10355
7.1930.1012d 1,eff1,eff ≤×
××
××
=
9.88dbut1.110d 1,eff1,eff ≤=
mm9.88d 1,eff =
6.101dbut6.101
3.63550.10355
7.1930.1012d 2,eff2,eff ≤×
××
××
=
6.101dbut100d 2,eff2,eff ≤=
mm100d 2,eff =
Reference
5.1.3 (Modified for three braces)
5.1.2.3
Welded Joints Examples CHS Chord CHS Bracings Overlap KT-Joint
51
where Brace Effective Width (overlapped brace);
jj,effj
jyj
00y
0
0j,eff ddbutd
tftf
dt12
d ≤××
××=
6.101dbut6.101
3.63550.10355
7.1930.1012d 3,eff3,eff ≤×
××
××
=
6.101dbut100d 3,eff3,eff ≤=
mm100d 3,eff =
Assume the hidden toes of braces 1 & 2 are NOT welded therefore;
( )2cweldeds/toehiddenIf1c
1c
s2s
1s==
=
Therefore;
( )( ) .......90cos11350cos48845cos369 ≤°+°−−°
........50sin
3.61006.1012100
2.65100
3470
45sin
0.59.889.882100
6.71100
3470
4 °
×⎥⎦
⎤⎢⎣
⎡+××⎟
⎠
⎞⎜⎝
⎛ −
×+°
×⎥⎦
⎤⎢⎣
⎡+××⎟
⎠
⎞⎜⎝
⎛ −
×⎜⎜⎝
⎛×
π
( )0.10.1
90sin3.610011001
3470
×⎟⎠
⎞°
××+××+
( ) 0.1341907380971267467
4kN575 ×++×
π≤
( )989745
4kN575 ×
π≤
Summary Here, the validity limits are combined to include all three braces. The eccentricity values use both brace 1 and 2 (diagonal) in relation to brace 3 (the vertical overlapped brace). The localised brace-to-chord shear check has been completed due to the high overlap. Please note that even if one brace is within limits for the brace-to-chord shear check, the check will still have to be calculated. In this example both diagonal braces overlap within the limits for the shear check. The brace-to-chord shear check equation sees the addition of the horizontal loads of the 3 bracings, the 2 angled braces having loads that result in the same horizontal direction. This means the brace 2 load (negative tension load) had to be subtracted so that the double-negative created a positive result so that the equation calculated correctly. It is important to check the joint configuration and refer to our Design of Welded Joints literature to make sure the correct method and formulae is used. To re-iterate this is a theoretical method which is not supported by research or tests.
Reference
5.1.2.3 5.1.3
PASSkN778kN575 ∴≤
Welded Joints Examples UB Chord RHS Bracings Gap K-Joint
12 UB Chord RHS Bracings Gap K-Joint
52
References are generally to Tata Steel publication ‘Design of Welded Joints’ (unless otherwise stated). Reference
Dimensions b0 = 125.3 mm h1 = 100.0 mm h2 = 100.0 mm h0 = 311.0 mm b1 = 100.0 mm b2 = 100.0 mm tw = 9.0 mm t1 = 6.3 mm t2 = 6.3 mm tf = 14.0 mm dw = h0 – 2 x (tf – r0) = 265.2 mm r0 = 8.9 mm Validity limits check 5.7.1 Figure 55 (EN1993-1-1 Chord: Web; Table 5.2) dw/tw ≤ 38ε (Class 1 or 2 compression) 38ε = 38 √(235/fy0) = 38 √(235/355) = 30.92 dw/tw = 265.2/9 = 29.5 ∴PASS dw ≤ 400 dw = 265.2 ∴PASS Chord: Flange; cf/tf ≤ 10ε (Class 1 or 2 compression) (EN1993-1-1 10ε = 10 √(235/fy0) = 10 √(235/355) = 8.1 Table 5.2) cf = (b0 – 2r0 - tw)/2 = (125.3 – 2 × 8.9 – 9)/2 = 49.25 cf/tf = 49.25/14.0 = 3.52 ∴PASS
Compression and Tension brace: hi/ti ≤ 35 hi/ti = 100/6.3 = 15.87 ∴PASS bi/ti ≤ 35 bi/ti = 100/6.3 = 15.87 ∴PASS hi/bi = 1.0 hi/bi = 100/100 = 1.0 ∴PASS Compression brace: (b1 – 3t1)/t1 ; (h1 – 3t1)/t1 ≤ 38ε (Class 1 or 2 compression) 38ε = 38 √(235/355) = 30.92 (b1 – 3t1)/ t1 = (100 – 3 × 6.3)/6.3 = 81.1/6.3 = 12.87 ∴PASS
g = 165.8mm
45° 45°
Np,Ed = 250 kN
N2,Ed = -150 kN N1,Ed = 150 kN
N0,Ed = 462 kN
SHS 100 x 100 x 6.3
UB 305 x 127 x 48 (S355)
MATERIAL; BRACES: CELSIUS S355 to EN 10210 UB CHORD: ADVANCE S355 to EN 10025
Welded Joints Examples UB Chord RHS Bracings Gap K-Joint
53
g ≥ t1 + t2 = 6.3 + 6.3 = 12.6 Reference g = 165.8 (zero eccentricity) ∴PASS 30° ≤ Ө1 ≤ 90° Ө1 = 45° ∴PASS 30° ≤ Ө2 ≤ 90° Ө2 = 45° ∴PASS Chord Web Yielding;
5M
i
i,ww0yRd,1 /
sinbtf
N γθ
××=
5.7.4
where… ( ) ( )0fi0fi
ii,w rt10t2butrt5
sinh
b ++≤++θ 5.7.2
( ) ( )9.80.14103.62but9.80.14545sin
100b 1,w ++×≤++°
=
bw,1 = 255.92 but ≤ 241.6 bw,1 = 241.6 mm and bw,2 = bw,1 as same brace and angle dimensions. Therefore;
kN10920.1/
45sin6.2410.9355N Rd,1 =
°××
=
and N2,Rd = N1,Rd as same brace and angle dimensions 1092 > 150 kN ∴PASS Chord Shear;
5Mi
0v0yRd,i /
sin3
AfN γ
θ×
×=
5.7.4
where… Av,0 = A0 – (2 - α) x b0 x tf + (tw + 2r) x tf 5.7.3
where…
⎟⎟⎠
⎞⎜⎜⎝
⎛
×
×+
=
⎟⎟
⎠
⎞
⎜⎜
⎝
⎛
×
×+
=α
2
2
2f
2
0.1438.16541
1
t3
g41
1
5.7.3
α = 0.073
∴ Av,0 = 6120 – (2 - 0.073) x 125.3 x 14.0 + (9.0 + 2 x 8.9) x 14.0
Av,0 = 3114.9 mm2
Welded Joints Examples UB Chord RHS Bracings Gap K-Joint
54
Reference
∴ 0.1/45sin3
9.3114355N Rd,1°×
×=
kN903N Rd,1 =
and N2,Rd = N1,Rd as same brace and angle dimensions 903kN > 150 kN ∴PASS Bracing Effective Width; 5Mi,effiyiRd,i /ptf2N γ×××= 5.7.4
Check if Bracing Effective Width required (Page 60 Welded Joints Literature); g / tf ≤ 20 - 28β 165.8 / 14.0 ≤ 20 – 28 (100+100+100+100/4 x 125.3) 11.8 ≤ -2.4 ∴ Check Effective Width; where… peff,i = tw + 2r + 7tf x (fy0 / fyi) 5.7.2 but ≤ bi + hi – 2ti for K or N gap joints peff,1 = 9.0 + 2 x 8.9 + 7 x 14.0 x (355/355)
but ≤ 100 + 100 – 2 x 6.3 peff,1 = 124.8 but ≤ 187.4 and peff,2 = peff,1 as same brace and angle dimensions 0.18.1243.63552N Rd,1 ÷×××= 558kN > 150kN ∴PASS
and N2,Rd = N1,Rd as same brace and angle dimensions Chord Axial Force Resistance in gap;
( ) 5MRd,0,pl
Ed,00y0,v0y0,v0Rd,gap,0 /
VV
1fAfAAN γ⎥⎥⎥
⎦
⎤
⎢⎢⎢
⎣
⎡
⎟⎟⎠
⎞⎜⎜⎝
⎛−××+×−=
5.7.4
where… ( )2Ed,21Ed,1Ed,0 sinN,sinNmaxV θ×θ×=
5.7.4
( )°×−°×= 45sin150,45sin150maxV Ed,0
Welded Joints Examples UB Chord RHS Bracings Gap K-Joint
55
Vo,Ed = 106.1kN Reference
where… ( ) ( )0.1
3/3558.31413/fAV
0M
0y0,vRd,0,pl
×=
γ=
5.7.4
Vpl,0,Rd = 643.9kN
( ) 0.1/9.6431.10613558.31413558.31416120N Rd,gap,0
⎥⎥⎦
⎤
⎢⎢⎣
⎡⎟⎠
⎞⎜⎝
⎛−××+×−=
N0,gap,Rd = 2077kN
check; N0,gap,Rd ≥ N0,gap,Ed
250kN 250.0 +106.1 356.1
Therefore; N0,gap,Ed = 356.1kN 2077kN ≥ 356.1kN ∴PASS
150kN 150kN
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