A seated connection is a type of steel connection where a beam rests on a seat or ledge on a column or support. It is commonly used in structural steel construction. The design criteria for a seated connection involve determining the required seat dimensions, connection capacity, and verifying the adequacy of the connection to safely transfer the applied loads. Here is a step-by-step procedure for designing an extended seated connection:
Step 1: Identify the Member Configuration Determine the specific configuration of the members involved in the connection, including the beam and the column. Gather information about their dimensions, material properties, and the connection requirements.
Step 2: Determine Applied Loads Identify the loads that will be applied to the connection, such as dead loads, live loads, wind loads, or seismic loads. Determine the magnitude, direction, and distribution of these loads.
Step 3: Analyze the Structure Perform a structural analysis of the entire structure to determine the forces and moments acting on the connection. Consider the loading conditions, support conditions, and member stiffness.
Step 4: Determine Required Seat Dimensions Calculate the required dimensions of the seat based on the applied loads, the desired connection capacity, and design code requirements. The seat dimensions should be selected to provide sufficient bearing area and stability for the beam.
Step 5: Check Seat Bearing Strength Check the bearing strength of the seat to ensure it can safely transfer the applied forces. Verify that the bearing stress is within the allowable limits specified by design codes or standards.
Step 6: Check Seat Stability Check the stability of the seated connection to ensure it can resist any potential overturning or sliding forces. Consider factors such as frictional forces and any additional means of connection or restraint.
Step 7: Check Beam Flexural Strength Check the flexural strength of the beam to ensure it can safely resist the applied bending moments. Verify that the bending stress in the beam is within the allowable limits specified by design codes or standards.
Step 8: Design Verification Perform a design verification to confirm that the extended seated connection meets the desired safety and performance requirements. This may involve performing structural analysis or calculations to confirm the adequacy of the seat dimensions and the connection capacity.
Example: Let’s consider the design of an extended seated connection between a steel beam and a column. The beam has a maximum moment of 150 kNm, and the desired connection capacity is 200 kNm. The material properties are as follows: beam and column yield strength = 250 MPa.
Step 1: Identify the Member Configuration The member configuration consists of a steel beam and a column, both with known dimensions and material properties.
Step 2: Determine Applied Loads The beam has a maximum moment of 150 kNm.
Step 3: Analyze the Structure Perform a structural analysis of the entire structure to determine the forces and moments acting on the connection.
Step 4: Determine Required Seat Dimensions Calculate the required seat dimensions based on the applied loads, the desired connection capacity, and design code requirements.
Step 5: Check Seat Bearing Strength Check the bearing strength of the seat to ensure it can safely transfer the applied forces.
Step 6: Check Seat Stability Check the stability of the seated connection to ensure it can resist any potential overturning or sliding forces.
Step 7: Check Beam Flexural Strength Check the flexural strength of the beam to ensure it can safely resist the applied bending moments.
Step 8: Design Verification Perform a design verification to confirm that the extended seated connection meets the desired safety and performance requirements.
The detailed calculations and formulas for each step can vary depending on the specific design code or standard being used. It is important to consult the relevant design code or consult with a qualified structural engineer to ensure accurate and compliant connection design.
