Vertical Dynamic Response of a Concrete Filled Steel Tube due to Transient Impact Load: Analytical Solution

This paper presents an analytical solution of vertical dynamic response of a concrete-filled steel tube (CFST) due to transient impact loading. Both the concrete and steel are modeled by linear elastic material. The impact load is simulated by a semisinusoidal impulse. Three-dimensional (3D) wave equations those considering the vertical displacement are established. By combining the initial and boundary conditions, the frequency-domain analytical solution of displacement is deduced by Laplace transformation and separation of variables methods. The time-domain dynamic response is then obtained by numerical inverse Fourier transformation (IFT). Numerical examples are presented to verify the validity of the analytical solution developed in this study. The results indicate that the analytical solution proposed in this study shows good consistence with the existing solutions.