Riveted Joints. Cannot be dismantled without some part of the joint being destroyed. Riveted joints were used in boilers, bridges, cranes etc

Riveted Joints  Permanent fastenings   Cannot be dismantled without some part of the joint being destroyed Riveted joints were used in boilers,...
Author: Dominic Hall
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Riveted Joints 

Permanent fastenings 



Cannot be dismantled without some part of the joint being destroyed

Riveted joints were used in boilers, bridges, cranes etc. 

Replaced widely by welding recently



Still in use in the production of structures made of light alloys 



Welding is not so reliable there

Production Process: 

Rivets are machine forged with single head, keeping proper size for the tail



Holes are punched or drilled on the parts to be joined



Rivets are made red-hot, inserted through the holes, keeping the rivet head firmly in place



The head on the other side is formed by pneumatic or hydraulic pressure



Contraction of the rivet, as it cools, draws the plates together closely

Rivets and Rivet Heads 

Rivet material must be strong and highly ductile



Rivets must resist mainly shearing action



Commonly adopted material for rivets is mild steel 



Copper brass or aluminium rivets can also be used if strength is not a leading factor

Rivet heads with various proportions are in use depending on applications 

Snap heads are used for structural work, pressure vessels and for machine riveting



Countersunk heads are used in ship building



For hand hammering, conical rivet heads are used

Types of Riveted Joints 



Lap Joint 

Single riveted



Double riveted



Triple riveted

Butt Joint 

Single Butt Strap Joints 



Double butt strap joints 



Single, double triple and quadruple riveted Single, double triple and quadruple riveted

Chain or Zigzag riveted joints

Types of Riveted Joints (Contd…)

Caulking and Fullering 

Edges of the plates for boilers tanks etc. are usually bevelled to an angle of 80º to facilitate fullering and caulking operations 

Edges are driven by a blunt tool to close the joints



Heads of the rivets are also turned down with a caulking tool to make the joint steam tight



Caulking requires skill; otherwise the joint may be damaged



Fullering is a better method

Failure of riveted joints 

Riveted and bolted joints loaded in shear are analysed in the same way



Since the lines of action of the forces are different, rivets and the members bend



The other modes of failure are: a)

Shear of rivet

b)

Tensile failure of members

c)

Bearing of rivet on members (or, bearing of members on rivet) – failure by crushing

d) & e) Shear tearout at the margin ( >> )

Failure by bending of the rivets or of the riveted members 

Bending moment, M ≈ Ft/2  



F is the shearing force t is the total thickness of the connected parts

Bending stress in the members (or, in the rivet) is assumed to be

σ = Mc/I ,

where, I/c is the section modulus for the weakest element (member or rivet) 

In design, this effect is taken care of, by a suitable increase in the factor of safety (

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