A pinned flange connection is a type of structural connection used in steel structures where the flanges of two beams are connected together using bolts, creating a pinned connection. The design criteria for a pinned flange connection involve determining the number and size of bolts required, ensuring that the connection can safely transfer the applied loads and moments. Here is a step-by-step procedure for designing a pinned flange connection:
Step 1: Identify the Member Configuration Determine the specific configuration of the beams and their dimensions. This includes the type of beams, their lengths, flange thickness, and material properties.
Step 2: Determine Applied Loads Identify the loads that will be applied to the connection. This includes dead loads, live loads, wind loads, and seismic loads. Determine the magnitude and distribution of these loads.
Step 3: Determine the Required Moment Capacity Analyze the applied loads to determine the required moment capacity at the connection. This can be done by considering the bending moments induced by the applied loads.
Step 4: Select Bolt Size and Grade Choose a suitable bolt size and grade based on the required moment capacity and the allowable stresses for the bolt material. Consider factors such as bolt diameter, thread type, and head type.
Step 5: Determine the Number of Bolts Determine the number of bolts required to safely transfer the applied loads. This can be done by dividing the total applied moment by the moment capacity of a single bolt.
Step 6: Check Bolt Strength Check the strength of the bolts to ensure they can safely transfer the applied loads. Verify that the stresses in the bolts are within the allowable limits for the bolt material.
Step 7: Check Bolt Spacing and Edge Distance Ensure that the spacing between bolts and the distance from the bolt holes to the edge of the flanges (edge distance) meet the requirements specified in design codes or standards.
Step 8: Check Connection Stiffness Check the stiffness of the connection to ensure that it can resist deformations and maintain its integrity under the applied loads. Consider the stiffness of the bolts and the flanges.
Step 9: Design Verification Perform a design verification to confirm that the pinned flange connection meets the desired safety and performance requirements. This may involve performing structural analysis or calculations to confirm the adequacy of the bolts, flanges, and their connections.
Example:
Let’s consider a pinned flange connection between two steel beams. The beams have flange thickness of 20 mm and carry a uniform live load of 10 kN/m. The applied moment at the connection is 100 kNm.
Step 1: Identify the Member Configuration The member configuration consists of two steel beams with flange thickness of 20 mm.
Step 2: Determine Applied Loads The beams carry a uniform live load of 10 kN/m. The applied moment at the connection is 100 kNm.
Step 3: Determine the Required Moment Capacity Analyze the applied loads to determine the required moment capacity at the connection. This can be done by considering the bending moment induced by the applied loads.
Step 4: Select Bolt Size and Grade Choose a suitable bolt size and grade based on the required moment capacity and the allowable stresses for the bolt material.
Step 5: Determine the Number of Bolts Determine the number of bolts required to safely transfer the applied loads. This can be done by dividing the total applied moment by the moment capacity of a single bolt.
Step 6: Check Bolt Strength Check the strength of the bolts to ensure they can safely transfer the applied loads. Verify that the stresses in the bolts are within the allowable limits for the bolt material.
Step 7: Check Bolt Spacing and Edge Distance Ensure that the spacing between bolts and the distance from the bolt holes to the edge of the flanges (edge distance) meet the requirements specified in design codes or standards.
Step 8: Check Connection Stiffness Check the stiffness of the connection to ensure that it can resist deformations and maintain its integrity under the applied loads. Consider the stiffness of the bolts and the flanges.
Step 9: Design Verification Perform a design verification to confirm that the pinned flange connection meets the desired safety and performance requirements. This may involve performing structural analysis or calculations to confirm the adequacy of the bolts, flanges, and their connections.
It is important to note that the specific design criteria, formulas, and calculations for pinned flange connections may vary depending on the specific application, design codes, and standards being used. It is recommended to consult the relevant design code or consult with a qualified structural engineer to ensure accurate and compliant joint design.
