The role of connectors in connecting the components of a construction project should not be underestimated. Connections or connections, especially in steel structures, have the role of dividing forces between members. It might be interesting to know that connection tools can be classified in different ways despite being compact .
Connections in steel structures can be divided into steel, concrete or combined categories based on their components. On the other hand, based on the degree of grip, they are divided into three types of joints, such as tight, semi-tight and simple joints in steel structures. Most of the structures you see around you are connected by semi-fixed connections, and the other two types, namely, fixed connections in steel structures and simple connections, are not used much. In this regard, this article examines the types of connections in steel structures. Stay with us until the end to get acquainted with these examples .
What are the types of steel structure connections? What are the advantages and disadvantages of using each of them? Welding and screwing operations are usually used to connect and integrate steel structure components. In building construction, even if quality beams and columns are used, if these connections are not properly implemented, the building will not have the necessary safety against various forces and will cause many human and financial damages .
All types of steel structure connections
In the past, rivets have been one of the tools used to connect steel structures; But today, screws and welding are used to connect the components of steel structures. Choosing the type of connecting tool and the correct method of connecting steel structures is one of the most important decisions in the construction of all types of structures. The most common connections of steel structures are :
- Riveted joints
- Screw connections
- welded joints
In the following, each of these connections is briefly described .
Riveted joints in steel structures
The oldest connecting tool in steel structures is the rivet. In the past, steel connections were made only by riveting or welding. Over time, instead of using rivets, high strength screws have been used. Nowadays, despite the new technologies, rivet joints are not used much .
But it should be noted that in order to have a correct understanding in the evaluation and reconstruction of old structures, familiarity with this type of connections is very necessary .
The rivet consists of three main components :
- cap
- shank
- trunk and tail
One of the joining processes of steel structures is riveting, which is done using rivets and in which two long and short rivets are used. The body of the rivet is made of steel with high tensile strength (carbon steel) and its structure is hollow .
To start this process, first the parts to be connected are drilled. Then the long rivet is heated with high heat and passed through the holes. In the next step, the short rivet is placed in front of the long rivet in the rivet machine .
In the last step, the rivet machine connects these two nails with high pressure, which creates a rivet connection. The use of riveting in steel structures has disadvantages, and for these reasons, this connection model has been removed from various standards. These disadvantages include :
- The use of riveting requires experienced and professional manpower, which will result in high costs .
- The use of riveting increases energy consumption and there is also a possibility of fire during the riveting operation .
- A lot of noise is generated during the riveting operation .
- Connecting metals using riveting operations has low resistance against natural events such as earthquakes .
- During maintenance operations, it is difficult to open and replace rivets that have already been installed .
Screw connections in steel structures
One of the most widely used connection tools in steel structures is the screw. In general, bolting refers to the process of connecting structural members using bolts and nuts. Screws and nuts are used to connect different parts. In the connections of steel structures, the most common types of screws are high strength screws. The screw with the code A307 is one of the normal screws with high strength .
High strength screws are divided into the following two groups :
- A with code A325
- B with code A490
These screws are used as construction screws .
Read more: types of building roofs; From the introduction to examining the advantages and disadvantages of each
Advantages of screw connections in steel structures
The process of screwing is very simple compared to riveting, and its implementation does not require professional labor. Screw connections have good flexibility, so it is easy to open and replace previously installed screws during maintenance operations. The use of this type of connection is suitable for components under tension, shear and combination. The use of screw connections in steel structures has the following advantages :
- The use of screws increases the construction speed of the structure, and as a result, the installation of connections is done at a high speed .
- The use of screws in the connections of steel structures does not require professional and skilled manpower .
- In the bolting process, the use of human power is reduced .
- No sound is produced during the screwing operation .
- The screwing process can be used even in small places .
Disadvantages of screw connections in steel structures
The use of screw connections in steel structures, in addition to the advantages we have mentioned, also has disadvantages, which include the following
- The use of screw connections causes loosening of the connections when vibration or shock loads are applied .
- When applying very high loads, there is a possibility of permanent failure of connections .
- There is a possibility of failure of connections due to corrosion of bolts and nuts .
- The use of screw connections requires materials that will incur high costs .
Welded joints in steel structures
In this connection, the desired members are connected by welding .
There are different types of welded joints, which include :
- welding type
There are different types of acne, such as angular (muscular) acne, digital acne, palate acne, groove acne .
- boiling mode
Welding modes include overhead, flat, horizontal, vertical .
- Connection type
Types of connection including corner, butt, shield, edge, overlapping .
Muscle welding is weaker compared to groove welding, but the strength of the welding during execution is high and it is more useful than other options. Finger welding and butt welding have a high cost and are weak in transferring tensile forces perpendicular to the surface. The quality of welded joints depends on the ability of the welder .
Advantages of welded joints in steel structures
The use of welded joints in steel structures has advantages, which include :
- The use of welded joints provides rigid joints .
- The use of welded joints has good resistance against applied loads .
- In complex structures, the use of welded joints will have a relatively simple implementation .
- To create different designs, the use of welded joints makes the design easier .
- High productivity is another advantage of using welded joints .
- The use of welded joints brings a better appearance to our structure .
- The use of welded joints creates a fabric structure .
Disadvantages of using welded joints
In addition to the mentioned advantages, the use of welded joints also has disadvantages, which include :
- They work poorly against shrinkage and cracking of joints .
- To use welded joints, expert labor is needed .
- The use of welded joints at high temperatures leads to fatigue .
- The use of welding joints causes the accumulation of welding slag .
- Maintenance of welded joints is very difficult and requires high precision .
Types of metal frame joints
Metal skeleton connections are generally divided into two categories :
- Simple connection
- Simple connection of beam to column
- Clamped connection
- joint beam to column
Simple connection
This connection is used in simple frames and connecting secondary beams to the main one. This method does not have any grip at the connection point, and it is easily done at the Duran connection point. Simple connection is designed and calculated only for shear force transfer .
Simple beam-to-column connections
There are two types of simple beam-to-column and king-beam connections, which include :
- Connection with angular pair of John
In the workshop, welding between corners and columns is done .
- Connection with the sitting corner
From the connection with the corner of the living room in almost small reactions up to about 15 Tons are used. One of the advantages of the sitting corner is the ease of installing and adjusting the beam .
Clamped connection
The connection of the receiver includes important points, including these connections :
- The use of clamping joints in the bending frame
- In comparison with the simple connection, the fastening connection is not done according to the degree of fastening .
- In the girder connection, the connection of the plates at the top and bottom is connected to the column wing in addition to the connection of the beam .
joint beam to column
Connecting the beam to the column is done in different ways, including :
- Connection of two continuous bridges of Khorjini
- Connecting two bridges to the side column
- Connecting a continuous bridge to the column
- Connecting three bridges to the column
- Connecting two continuous Khurjini bridges and two non-continuous bridges
1. What are the characteristics of beam-to-column joints?
This type of connection is formed in two ways: 1- Rigid and tight connections in steel structures 2- Jointed .
The following items include each of the mentioned modes :
- Rigid connection with parallel and coupled plates
- Rigid connection with a pair of structural shields
- Rigid connection with the most end plate on the column in the structure
The rigid connection of the beam to the column is intended to transfer the anchor of the column so that there is no rotation between the connected members. This type of connection includes various types that, due to their breadth, it is possible to mention them in a separate article. Generally, in this type of connection, which is done in the form of welding, it is done either in the manufacturing plant itself or during construction on the ground. In this case, there is a need for a steel structure connection plan .
On the other hand, we are dealing with joint connections in steel structures, which are used in most buildings to connect two pieces due to the simplicity of the connection. The method of joints in steel structures is also welding, which changes their shape. Welding of joint joints in steel structures is done in such a way that only the top and bottom are welded in the corners and the other parts should not be welded; Because it causes the structure to be unbalanced .
Types of joints in steel structures and how they are
Articulated joints in steel structures generally include three categories :
- simple sitting type connection (sitting corner)
- Connection by the sitting plate and structure flexibility
- Connection by the seat plate and cutting plate or blade in the structure
Most of today’s structures around the world use the first two connections and are standing. The third type is not used much because of its difficulty and high risk. These connections are in such a way that in the rigid direction of the structure, the connection is parallel to two planes, and in the joint direction, the connection is made through the sitting corner and flexure in the structure. In the joint connection, the angle between the beam and the column can be changed, while in the rigid type connection, this angle does not change. It is better not to forget this point that in the first type of connection, i.e. the simple sitting connection, the upper corners are used with the purpose of creating balance in the structure, not just for load .
2. What are the features of column foot connection?
This type of connection also includes rigid and joint connections. The rigid connection is connected with the help of stiffeners in the direction of moment and the joint connection is connected by using angle and lath, which was the second method of connection in steel structures and in the direction without moment. These two joints connect and establish the foot of the column in a strong and resistant manner, while if the joint weld at the foot of the column wants to use these two joints, it must have the proper conditions and substrate for these two joints .
3. What are the characteristics of connecting two beams together?
Sometimes, in construction, two beams must be connected together for greater strength. This connection is also called beam to beam or double beam. This connection has two general forms :
- a) In the first type, the extensions of two beams are perpendicular to each other, which is also called beam-to-beam connection or beam-to-beam connection; In fact, this connection is created with the aim of transferring all the load and its weight from one beam to another beam and dividing the load weight between both beams .
- b) Connecting two beams with the aim of increasing the length of both beams .
How to connect the king beams to each other
But the connection of the two main beams, which are also known as king beams, is such that the king beam, which has a larger opening, is placed inside the king beam, which has a small opening .
In fact, in order to form a double column by connecting two beams together, two main beams are connected by means of plates or fasteners .
Read more : Golden tips in the decoration of work and office environments
Conclusion
By reading this article, we found that the connections of steel structures play a key role in determining the safety level of buildings. Paying attention to this issue is one of the most important issues in the construction industry. During the article, we learned about the types of steel structure connections and the advantages and disadvantages of each. We hope that by reading this article, you have obtained the necessary and sufficient information about the subject of the content, thank you for your cooperation .
No comment