It is very critical to design steel structures due to different failures from different parts of the structure. In steel structures, there may be a failure of rivet, bolt, or plate due to shear, tear, bending, and twisting. We have to design the steel structure by taking the minimum strength as a reference of the strength of the whole member.
Considering the economical and safe aspect of the design of steel structures, we should provide a proper measurement of pitch, guage, the thickness of steel plate, rivet and bolts, etc. More pitch may weaken the structure while less pitch may make the steel structure expensive.
Now, let us see the Design of Riveted connections in steel structures with the technical terms used for designing.
The distance between two adjacent rivets in an arrow parallel to the direction of stress is known as pitch.
How much should be the minimum pitch (Pmin)?
To avoid tension or tearing failure of rivets, the minimum pitch should not be less than 2.5 times the diameter of rivets.
How much should be the maximum pitch(Pmax)?
To avoid buckling failure, the following points should be remembered.
- For compressive member, 12 tmin or 200 mm whichever is lesser in the direction of stress.
- For tension member, 16 tmin or 200 mm whichever is lessr in the direction of stress.
- Fo both, 32 tmin or 300 mm whichever is lesser perpendicular to the stress.
- (100 mm + 4t) or 200 mm whichever is less.
- Diameter of rivet hole should be 1.5 mm (<25 mm) and 2 mm (>25mm) greater than rivet.
The center to center distance between two adjacent rivets perpendicular to the direction of stress is known as guage.
3) Edge distance
The distance between the center of the rivet hole and the nearest edge of the plate is known as edge distance.
To avoid shear and splitting failure of plate minimum edge distance should be maintained.
p = pitch
d = diameter of the rivet hole
t = thickness of the plate
What is critically loaded rivets?
The rivets which are located at a further distance from c.g of rivet groups and closer to the load (w) are subjected to the higher value of resultant shear force. These rivets are called critically loaded rivets.
What is Tacking rivets?
It is a type of rivets used to maintain the maximum pitch within the limit is called tacking rivets. These rivets are not used for calculating the strength of the rivet. Tacking rivets are also called stitch rivets. it is also used to connect two angles. the maximum pitch for tacking rivet for compression member should be exceeded 600mm.
Permissible stress in rivet
|S.N||Description||Axial Tension (N/mm2 )||Shear(N/mm2)||Bearing(N/mm2)|
|2||Hand driven Rivets||80||100||250|
Numerical Example for Design of Riveted connections in steel structures
I hope this article on “Design of Riveted connections in steel structures” remains helpful for you.
Happy Learning – Civil Concept