What is Welded Flange Plate Connection? Explain in details step by step procedure to make a Welded Flange Plate Connection with example and application.

A welded flange plate connection is a structural connection used to join two or more steel members together, typically in the construction industry. It involves the use of flanges, which are flat, circular plates with holes, welded to the ends of steel beams or columns, and then bolted together to form a connection. This type of connection provides stability, strength, and rigidity to the overall structure.

Here is a step-by-step procedure to make a welded flange plate connection:

Step 1: Design and Calculation

• Determine the loads and forces acting on the structure, including axial, shear, and bending forces.
• Determine the required size and thickness of the flange plates based on the applied loads and the material properties.
• Calculate the required number and size of bolts for the connection, considering the forces they will need to withstand.

Step 2: Preparation

• Gather the necessary materials, including the steel members (beams or columns) and the flange plates.
• Ensure that the surfaces to be welded are clean and free from rust, oil, paint, or any other contaminants.
• Prepare the welding equipment, such as welding machine, electrodes, and protective gear (e.g., welding helmet, gloves, etc.).

Step 3: Positioning and Alignment

• Position the steel members in their desired locations, ensuring proper alignment and orientation.
• Place the flange plates over the ends of the steel members, ensuring they are centered and aligned with the beam or column edges.
• Use clamps or tack welds to temporarily hold the flange plates in place.

Step 4: Welding

• Start by tack welding the flange plates to the steel members. Tack welds are small, temporary welds that hold the plates in position.
• Double-check the alignment and dimensions before proceeding with the final welding.
• Weld the flange plates to the steel members using an appropriate welding technique, such as shielded metal arc welding (SMAW) or gas metal arc welding (GMAW).
• Ensure that the welds penetrate the full thickness of the flange plates and provide complete fusion with the steel members.

Step 5: Quality Control

• Inspect the welds visually to ensure they are free from defects such as cracks, porosity, or incomplete fusion.
• Conduct non-destructive testing (NDT) techniques like ultrasonic testing or magnetic particle inspection to verify the integrity of the welds.
• Verify the dimensions, alignment, and overall quality of the connection according to the design specifications.

Example and Application: Let’s consider an example of a welded flange plate connection in a steel building. Suppose you have two steel columns that need to be connected to a horizontal steel beam.

In this case, flange plates will be welded to the ends of the columns, and the beam will be bolted to these flange plates. The flange plates provide a larger bearing surface for distributing the load from the beam to the columns. The bolts add additional strength and stability to the connection.

This type of connection is commonly used in the construction of steel buildings, bridges, and other structures where the strength and rigidity of the connection are critical. Welded flange plate connections are preferred when the applied loads require a robust and secure connection that can resist bending, shear, and axial forces.

In summary, a welded flange plate connection involves welding circular plates (flanges) to the ends of steel beams or columns, followed by bolting them together. It provides a strong, stable, and rigid connection for steel structures, ensuring the overall stability and integrity of the construction.