What is Extended End-Plate Connection? Explain in details step by step procedure to make a Extended End-Plate Connection with example and application.
An extended end-plate connection is a type of structural connection used to join steel beams to columns in steel structures. It involves the use of extended end-plates attached to the beam and column flanges, along with bolts, to create a rigid and moment-resisting connection. This type of connection is commonly used in buildings, bridges, and other structures where high load-bearing capacity and resistance to bending moments are required.
Here is a step-by-step procedure for making an extended end-plate connection:
- Design and Preparation:
- Determine the required strength and load-bearing capacity of the connection based on the structural requirements.
- Select the appropriate extended end-plates, bolts, and other connection components based on the design specifications, considering factors such as material strength, size, and corrosion resistance.
- Ensure that the beam and column flanges are clean, smooth, and free from any debris, rust, or paint.
- Alignment and Positioning:
- Position the beam and column in their designated locations, ensuring proper alignment and fit.
- Use temporary clamps or tack welds to hold the beam and column in place, ensuring they do not move during the connection process.
- Marking and Drilling:
- Mark the positions for the bolt holes on the beam and column flanges, following the specified spacing and pattern.
- Use a drill press or portable drilling machine to drill holes through the marked positions on both the beam and column flanges. Ensure that the holes are perpendicular to the flange surfaces.
- Deburring and Cleaning:
- Remove any burrs or sharp edges around the drilled holes using a deburring tool or file.
- Clean the holes and flange surfaces to remove any debris, oil, or grease, as these can affect the connection’s integrity.
- Attaching the Extended End-Plates:
- Position the extended end-plates on the beam and column flanges, aligning the holes with the drilled holes.
- Insert bolts through the holes in the extended end-plates, beam flanges, and column flanges, ensuring a proper fit.
- Place flat washers and nuts onto the exposed ends of the bolts.
- Tightening the Bolts:
- Begin tightening the bolts using an appropriate wrench or torque wrench.
- Tighten the bolts gradually and evenly in a crisscross pattern to distribute the load and prevent distortion of the connection.
- Follow the recommended torque specifications provided by the bolt manufacturer or the design engineer.
- Welding (Optional):
- In some cases, additional welding may be required to enhance the connection’s strength and rigidity.
- Welds may be applied between the extended end-plates and the beam flanges, as well as between the extended end-plates and the column flanges.
- The welding process should be carried out by qualified welders, following the applicable welding codes and standards.
- Final Inspection:
- Inspect the connection to ensure that the extended end-plates are securely attached to the beam and column flanges.
- Check for any gaps, misalignment, or visible signs of damage or distortion.
- Verify that the bolts and nuts are properly seated and tightened.
Example and Application: An example of an extended end-plate connection is the connection between a steel beam and a steel column in a multi-story building frame. The extended end-plates are attached to the beam and column flanges, and bolts are used to secure the connection. This type of connection provides resistance against bending moments and enhances the overall stability and strength of the structure.
Applications of extended end-plate connections include:
- Multi-story buildings, where the connection between beams and columns is crucial for supporting the floors and transferring loads.
- Bridge structures, where the connection between girders and piers is required to withstand high bending moments and dynamic loads.
- Industrial facilities and warehouses, where large steel frames are used to support heavy loads and equipment.
Extended end-plate connections offer excellent load-bearing capacity, rigidity, and resistance to bending moments. They are commonly used in steel structures where reliable and durable connections are essential for structural integrity.