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Example 1

Two PLATES OF 130×8( GRADE 300W) ARE CONNECTED TOGETHER USING M16 BOLTS IN PUNCHED HOLES AND THE EDGES OF THE PLATES ARE GAS-CUT.
( 1 ) check the spacing configuration.
( 2 ) Determine the tensile Resistance.
PITCH IS 60mm
EDGE IS 35mm
END IS 35mm
Steps to follow:
Calculate ;
i). Spacing configuration
ii). Modes of failure in Bolt Connections
iii). Bolt shear
v). Bolt bearing
Notes : fu = 450Mpa for 300W
fu = 480Mpa for 350W
m is Number of shear planes :
1 for single shear plane
2 for double shear plane



User Eric Cope
by
8.1k points

1 Answer

3 votes

Answer:

i) Spacing configuration:

The spacing configuration for bolted connections is important to ensure that the bolts can effectively transfer the load between the two plates. The pitch, edge, and end distances are critical to ensure the integrity of the connection.

Given:

Plate dimensions = 130 x 8 mm

Fu = 450 MPa

Bolt size = M16

Pitch distance = 60 mm

Edge distance = 35 mm

End distance = 35 mm

The minimum pitch distance for M16 bolts can be calculated as:

p = 2.5d

where d is the bolt diameter

For M16 bolts, d = 16 mm

Therefore, p = 2.5 x 16 = 40 mm

Since the pitch distance given is 60 mm, it meets the minimum requirement.

The minimum edge distance for a punched hole is given by:

e = 1.2d

where d is the bolt diameter

For M16 bolts, e = 1.2 x 16 = 19.2 mm

Since the edge distance given is 35 mm, it meets the minimum requirement.

The minimum end distance for a punched hole is given by:

end = 1.5d

where d is the bolt diameter

For M16 bolts, end = 1.5 x 16 = 24 mm

Since the end distance given is 35 mm, it meets the minimum requirement.

Therefore, the spacing configuration meets the minimum requirements.

ii) Modes of failure in bolt connections:

The modes of failure in bolted connections include bolt shear, bolt bearing, and plate tearing. Bolt shear occurs when the force on the bolt is perpendicular to the axis of the bolt. Bolt bearing occurs when the force on the bolt is parallel to the axis of the bolt, causing the bolt to deform and crush the material around it. Plate tearing occurs when the force on the bolt causes the plate to tear apart.

iii) Bolt shear:

The tensile resistance of a bolt in shear can be calculated as:

Fv = 0.6FuA / m

where Fv is the tensile resistance of the bolt in shear, Fu is the ultimate tensile strength of the bolt material, A is the tensile stress area of the bolt, and m is the number of shear planes.

For M16 bolts, the tensile stress area can be calculated as:

A = π/4 (d^2)

where d is the bolt diameter

For M16 bolts, A = π/4 (16^2) = 201.06 mm^2

For single shear plane, m = 1

Therefore, the tensile resistance of a single M16 bolt in shear can be calculated as:

Fv = 0.6 x 450 x 201.06 / 1 = 54,047.19 N

For two bolts, the total tensile resistance in shear would be:

Fv = 2 x 54,047.19 = 108,094.38 N

iv) Bolt bearing:

The tensile resistance of a bolt in bearing can be calculated as:

Fb = 2.4dt t Fu / m

where Fb is the tensile resistance of the bolt in bearing, dt is the thickness of the connected plate, t is the thickness of the washer, Fu is the ultimate tensile strength of the bolt material, and m is the number of shear planes.

For M16 bolts, the thickness of the washer is typically 4 mm.

The tensile resistance of a single M16 bolt in bearing can be calculated as:

Fb = 2.4 x 8 x 4 x 450 / 1 = 34,560 N

For two bolts, the total

Step-by-step explanation:

User Amit Pandya
by
7.1k points