1. Module I: Bolted and Welded Connections

Riveted Connections Traditionally used before the widespread adoption of bolting and welding. Rivets are cylindrical steel pins driven while hot through pre-drilled holes in the connected members, expanding to fill the hole as they cool. Not common in modern structural steelwork due to labor intensity and better alternatives.

Riveted connections represent an older method of joining steel parts, where rivets—hot-forged steel pins—are driven into precut holes. As they cool, they expand, locking the parts together. This method has largely fallen out of favor in favor of bolting and welding, which are quicker and require less manual labor.

Think of riveted connections like connecting wooden parts using wooden dowels. Just like dowels must be precisely cut and glued, rivets need specific holes, and the process can be quite slow and labor-intensive. Traditionally, buildings were assembled this way, but today we prefer quicker methods, similar to how flat-pack furniture is assembled using screws nowadays.

Bolted Connections Bolted joints use high-strength bolts (HSFG) to connect structural steel members. Preferred for ease, speed, and clean installation. Types:

• Bearing-type: Shear transferred by bolt bearing on holes.
• Friction-type: Shear resisted by friction between connected plates, achieved by pre-tensioned bolts. Common Applications: Beam-to-beam, beam-to-column, bracket plates.

Bolted connections are a modern way to join metal parts, using high-strength bolts that provide a secure and reliable hold without the need for extensive labor. There are two main types: bearing-type bolts transfer shear through the hole's bearing, while friction-type bolts create a strong connection through tension. These joints are used in many applications, such as connecting beams to columns.

Imagine assembling a large piece of furniture with bolts instead of nails. Bolted connections allow for easy assembly and disassembly, just as we can take apart flat-pack furniture for moving. Similar to how some items use pressure from bolts to hold together tightly (like joining two board pieces), structural applications rely on these connections to carry heavy loads.

Welded Connections Welds create joints by fusing steel parts using heat with/without filler. Strong, rigid, and suited for prefabrication. Types:

• Fillet welds: Triangular cross-section, common for lap, tee, and corner joints.
• Butt welds: Joining ends of plates typically in the same plane.

Welded connections use heat to fuse pieces of steel together, creating a strong and rigid bond. Welds can be done with or without additional filler material. The two common types include fillet welds, which are used at various joint angles, and butt welds, used to connect the ends of plates. Welds are beneficial for prefabricated elements as they create a seamless connection.

Think of welding like melting chocolate to fuse together two pieces of cake. Just as the melted chocolate creates a strong bond when it cools and sets, welding applies heat to steel parts, allowing them to fuse permanently. This method would make a cake structure incredibly solid, similar to how welded joints provide strength to steel structures.

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