DYNAMIC BEHAVIOR OF REINFORCED CONCRETE COLUMN UNDER ACCIDENTAL IMPACT

Abstract

The analysis of scientific literature shows that to date, the physical parameters of the deformation of reinforced concrete bar structures during their dynamic buckling and the influence of the dissipative properties of the structural system on this process remain insufficiently studied. In this regard, the paper proposes an analytical solution to the problem of dynamic buckling of a reinforced concrete column when it is loaded with an impact load, taking into account the presence of initial geometric and (or) physical imperfections and damping properties of the system, as well as an analysis and assessment of the column deformation parameters based on the obtained analytical solution. An expression for the dynamic deflection of a bar element under its axial loading with a high-speed shock load, taking into account damping, is obtained in an analytical form. For practical calculations in a quasi-static formulation, the paper proposes an expression for the dynamic factor kd of bar structures under axial shock load. A numerical example of calculating a reinforced concrete column using the obtained analytical expressions with and without damping is considered. It was found that the maximum deflection of the elastic axis of the column under high-speed loading was achieved at t = 0.04 s. In this case, the total dynamic deflection taking into account damping was 4.8% less than the deviation without taking into account damping and 1.18 times more than the corresponding static value.

Keywords

• reinforced concrete, column, buckling, accidental impact, progressive collapse, deflection, velocity, acceleration