DESIGN OF COMPOSITE BEAM-COLUMNS Circular Concrete Section With Doubly Crossed Steel Profile

Designing a composite beam-column with a circular concrete section and a doubly crossed steel profile involves combining the strength and stiffness of both materials to create a structural member capable of carrying axial and bending loads. Here’s a step-by-step approach to designing such a composite beam-column:

1. Determine the loads: Identify the axial load and the bending moment applied to the composite beam-column. These loads are typically obtained from the structural analysis of the overall structure.
2. Select steel profile: Choose a suitable doubly crossed steel profile that will act as the internal steel reinforcement within the composite section. The steel profile should be selected based on the desired strength and stiffness requirements.
3. Determine the section properties: Calculate the section properties of the composite section, including the area, centroid, and moment of inertia. For a circular concrete section with a doubly crossed steel profile, these properties can be determined by considering the properties of both the concrete and steel components of the section.
4. Calculate the effective flange width: The effective flange width is the portion of the steel profile that contributes to the composite action. It depends on factors such as the connection details and the width of the concrete slab (if present). Consult design codes or engineering references for guidance on calculating the effective flange width.
5. Check for overall stability: Verify that the composite beam-column satisfies the stability requirements. This involves checking for buckling and lateral-torsional buckling using appropriate formulas and design standards.
6. Check for axial load capacity: Determine the axial load capacity of the composite section. Calculate the axial resistance of both the concrete and steel components and compare them to the applied axial load. Ensure that the section is capable of carrying the applied axial load without exceeding the design limits.
7. Check for bending capacity: Calculate the moment capacity of the composite beam-column using appropriate design formulas. Consider the contribution of both the concrete and steel components to the moment resistance. Verify that the section is capable of resisting the applied bending moment without exceeding the design limits.
8. Check for shear capacity: Evaluate the shear capacity of the composite section. Calculate the shear resistance of the concrete and steel components and ensure that the section can resist the applied shear force without failure.
9. Design the reinforcement: Determine the required reinforcement for the steel profile and the concrete section. Calculate the required steel reinforcement to resist the bending moment and shear forces. The reinforcement design should comply with the relevant design codes and standards.
10. Detailing and construction: Develop the reinforcement detailing, including the placement and anchorage of the steel reinforcement within the circular concrete section. Consider the connection details between the steel profile and the concrete to ensure proper load transfer and composite action.