The steel structures are constructed by properly connecting the available standard sections. The connections are an important part of steel structure and are designed more conventionally than any individual members. There is a discrepancy between the actual behavior and the analysis of steel structure is large, therefore the connections are complex to analyze and design. When the structural member fails in case of overloading then there is a general practice to prefer the individual member rather than the connections, therefore this kind of practice affects many structural members. The cost of structural steel consists of major portion of connections and that is the reason primary importance should be given to the design of connections for safety and economy of structure.
The connections are generally provided in the following cases:
The classification in the connections provided in the steel structure is as follows:
The riveted connections are nowadays obsolete. The understanding of this type of connections for the strength evaluation and rehabilitation for an older structure is essential. While the connection procedure for riveted connections is same as that of the bolted connections.
A rivet is made up of round ductile steel bar which is called as ‘shank’ and with a head at the one end. It is made up of mild steel or high tensile steel.
Riveting is the particular method of connecting together pieces of metal. This process is conducted by inserting the ductile metal pins called as rivet into the holes of pieces to be joined and formed a head at the end of the rivet to prevent each metal piece from coming out.
The shank of the rivet is made up of the length to the extent through the different parts which is to be connected and with sufficient extra length for a second head to be made at the other end.
The rivets are generally classified as follows:
When hot driven rivets are properly cooled down then the diameter and shank length get reduced. Because of this, the compression of the plates occurs and that results in friction between the plates, this process is called as clamp action.
Disadvantages of riveted connections are as follows:
Most commonly used connections include the bolted connections. This connection has the advantage of flexibility in assembling parts of the structure as well as dissembling it and which is necessary if there is inspection or some routine maintenance. This type of connections is applicable for members subjected to tension or shear or both tension and shear.
A bolt is a metal pin with a head formed at one end and the shank threaded at the other end so that nut can be received. Generally, the bolts are used to connect the pieces of metals by inserting them through the holes in the metals; at the threaded end, nuts should be tightened.
The advantages of bolted connections are as follows:
The disadvantages of bolted connections are as follows:
Classification of bolted connections:
The classifications of bolted connections are made on the basis of resultant force transferred, type of force and force mechanism.
On the basis of resultant force transferred:
On the basis of type of force:
On the basis of force mechanism:
The design philosophy:
The conventional method to analyze the connection is based on the following conditions:
In practical situations, the connected sections like angles, gusset plates, etc are flexible deformation occurs at the low intensity of load also.