Bolt Design Update 27aug

8/8/2019 Bolt Design Update 27aug

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All these relations are valid for ISO-metric threadsNominal diameter Pitch Input Output

1st 2ndcoarse fine

choice choice

1 0.251.2 0.25

1.4 0.3

1.6 0.35

1.8 0.35

2 0.4

2.5 0.45

3 0.5

3.5 0.6

4 0.7

5 0.8

6 1

7 18 1.25 1

10 1.5 1.25 or 1

12 1.75

14 2 1.5

16 2 1.5

18 2.5 2 or 1.5

20 2.5 2 or 1.5

22 2.5 2 or 1.5

24 3 2

27 3 2

30 3.5 2

33 3.5 2

36 4 3

39 4 3

42 4.5 3

45 4.5 3

48 5 3

52 5 4

56 5.5 4

60 5.5 4

64 6 4

D (mm) P (mm)

1.5 or1.25


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Nominal diameter D [mm] 20

Pitch P [mm] 2.5

Height of the fillet H [mm] 2.17

Stress area A [mm^2] 244.79


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SafectyNominal diameter D [mm] 30

Pitch P [mm] 3.5



Bolt class 8 . 8

Yeld strenght Fnt 640 [N/mm^2]

Ultimate tensile strenght fub 800 [N/mm^2]

Allowable shear stress Fnv 369.5 [N/mm^2]

Design tensile force Fa 90000 [N]

Design shear force Fs 30000 [N]

Design tensile stress 160.5 [N/mm^2]

Design shear stress fv 53.5 [N/mm^2]

Tensile resistance Rt ### [N] 179.39 [kN]

Shear resistance Rs ### [N] 103.57 [kN]

Combined stress resistance:

Modified nominal tensile stress F'nt 646.62 [N/mm^2]

Allowable modified axial force R't ### [N] 181.24 [kN]

Bearing resistance of holes:

Distance between holes Lc 34 [mm]

Thickness of connecting material t 30 [mm]

Fu 490 [N/mm^2]

Bearing strenght:

Rn 599.76 1058.4 [kN]

Rn 749.7 1323 [kN]

Write Rn Rn 599.76 [kN]

Allowable Bearing strenght Rall 299.88 [kN]

a

Ultimate tensile stress of the connectingmaterial

If the deformation of the hole is a designconsideration (Saipem case) Is the smallerof the the two numbers

If the deformation of the hole is not adesign consideration. Is the smaller of thethe two numbers


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factor of 2 already included

Design forces:

> 90 [kN]

> 30 [kN]

> 90 [kN]


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Pitch P [mm] 3



Bolt class 8 . 8




Axial force Fa 90000 [N]

Shear force Fs 30000 [N]

Load factor gamma f 1.3

Tension resistance

K2

If countersunk bolt 0.63

otherwise 0.9

Write K2 0.9

Tension resistance Ft,rd 203.0 [kN] < 117

Shear resistance

for classes 4.6,5.6,and8.8 0.6

for classes 4.8,5.8,6.8 and 10.9 0.5

Write v 0.6

Shear resistance Fv,rd 135.4 [kN] < 39

Combined loads, shear and tension

The bolt is adequate if 0.78


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For end bolts 0.64

For inner bolts 1.03

1.03

1.03 1.6 1

1

For edge bolts k1 smallest of 2.0 2.5

For inner bolts k1 smallest of 5.3 2.5

Write k1 2.5

Allowable bearing strenght: Fb,rd 705.6 [kN]

Write ad

ab is the smallest of

Write abPerpendicuular to the direction ofload transfer


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factor already included

[kN]

[kN]


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Pitch P [mm] 3

Diameter of the head d [mm] 46



Area of plate A 400 [mm^2]

Total thickness of the connecting elements t 30 [mm]

Modulus of elasticity of the plate Ep 210000 [N/mm^2]

Bolt class 8 . 8




Modulus of elasticity of the bolt Eb 210000 [N/mm^2]

Friction coefficient 0.3

External shearing force Fs 30000 [N]

Minimum pretension necessary Tf 9000 [N]

Axial external load P2 90000 [N]

minimum initial preload Ti 62282.02

University design

Allowable bolt load 297188.41 [N] safety factor of 1.25 (=

Preload 210000 [N]

Allowable shear of the connection 30000 [N] safety factor of 1.2 incl

Advisable order of magnitude of preload 260039.86 [N]

Torque necessary to obtain preload 1260 [Nm]

Stiffness

Bolt stiffness kb ###

Plate stiffness kp ###

Double check kp ### considerando l'area ci


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Load on the bolt due to repartition of load F 15706 [N]

Load on the plate due to repartition of load F 74294 [N]

Total load on the bolt 225706 < 297188.41 per non ro

minimum plate connection load 135706 > 0 per evitare


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factor not included

1/0.8) included

uded

colare della lastra meno il foro


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pere la vite

il distacco


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Bolt Design Update 27aug

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