Ningxia Xinjiuheng Steel Structure Engineering C

There are three types of steel structure connections: welded joints, bolted joints, and riveted joints.
Welded joints
Welding joints are formed by the heat generated from an electric arc, which locally melts the welding rod and the workpiece, then cools and solidifies to create a weld, thereby joining the workpieces into a single unit.
Advantages: Does not reduce the cross-section of components, saves steel, simple construction, easy manufacturing, high connection stiffness, good sealing performance, easily adaptable to automated operations under certain conditions, and high production efficiency.
Disadvantages: The heat-affected zone near the weld, formed by the high temperatures of welding, can cause some areas of the steel to become brittle; the uneven heating and cooling of the steel during the welding process can lead to residual stresses and deformation in the structure, which have an impact on its load-bearing capacity, stiffness, and performance; due to its high stiffness, welding structures can easily spread local cracks to the entire structure, particularly prone to brittle fractures at low temperatures; the plasticity and toughness of the weld joints are poor, which may lead to defects during welding and reduce the fatigue strength.
Bolted Connection
Bolt connections involve fastening components together using bolts as the fastening element. There are two types of bolt connections: ordinary bolt connections and high-strength bolt connections.
Advantages: Simple construction techniques, easy installation, especially suitable for on-site installation and connection, easy to dismantle, and ideal for structures requiring assembly and disassembly or temporary connections.
Shortcomings: Requires drilling and alignment of holes during panel assembly, which increases manufacturing workload and demands higher precision. Bolt holes also weaken the cross-section of the components, and the connected parts often need to overlap or additional auxiliary connection plates (or angle irons) are required, making the structure more complex and consuming more steel.
Screws and Bolts Connection
Bolting connections involve inserting a bolt with a preformed semi-circular head into a hole in the connecting part. After heating the bolt shank red-hot, it is quickly driven into the hole. Then, a rivet gun is used to form the other end into a head, securing the connection.
Advantages: Riveted joints offer reliable load transfer, with good plasticity and toughness, quality that is easy to inspect and ensure, suitable for structures subjected to heavy loads and direct dynamic forces.
Flaws: The riveting process is complex, labor-intensive, and material-intensive, and thus has been largely replaced by welding and high-strength bolt connections.