In modern structural engineering, the connection between steel beams and Concrete-Filled Steel Tube (CFST) columns plays a crucial role in the overall stability and performance of composite frame structures. CFST columns combine the benefits of steel and concrete, offering high strength, ductility, and energy absorption capacity, which are essential for resisting dynamic loads such as those induced by earthquakes, blasts, or impacts.

The beam-to-CFST column connection, often made using bolts, is a critical structural detail that governs the load transfer and deformation characteristics of the frame under dynamic actions. Bolted connections offer advantages such as ease of installation, maintainability, and potential for controlled failure mechanisms. However, under dynamic loading, these connections are subjected to complex stress states involving shear, tension, and bending, which can lead to different modes of failure, including bolt shear failure, bolt slip, fracture of steel elements, or local buckling of the CFST column.

Dynamic failure analysis of these connections is essential for understanding their behavior under transient loads and ensuring structural safety and resilience. This involves studying the interaction between the steel beam, bolted connection, and CFST column under high-strain rates, impact forces, or cyclic loading typical of seismic events.

Key aspects of the analysis include:

• Load transfer mechanisms within the connection during dynamic events,

• Deformation and failure modes of bolts and surrounding steel elements,

• Effect of bolt pre-tension, spacing, and arrangement on connection performance,

• Contribution of the concrete infill to overall stiffness and energy dissipation,

• Numerical simulations and experimental testing to predict failure modes and optimize design.

Understanding these factors enables engineers to design safer, more ductile, and energy-absorbing beam-to-column connections, enhancing the overall performance of steel-concrete composite frames in dynamic environments.