ON THE CALCULATION OF REINFORCED CONCRETE BEAM STRUCTURES ON THE EFFECT OF SHORTTERM DYNAMIC LOADS
The paper presents the calculation method of reinforced concrete beam on the action of non-periodic loads of high intensity using the differential equation of motion. This class of loads refers to special loads that last for a fraction of a second. When calculating the design for such impacts, it is advisable to take into account the development of plastic deformations in the cross sections, with the formation of plasticity joints due to reaching the yield point in the working longitudinal armature. It is noted that at an increased rate of deformation of reinforcement and concrete structures, there is a delay in plastic deformations in them, and this leads to an increase in the strength characteristics of materials. The values of dynamic hardening coefficients for reinforcing steels and concrete are given, depending on their deformation rate. An example of calculation of a single-span freely supported beam for the action of an instantaneous pulse is performed. The calculation is based on the elastic-plastic model of structural deformation under load. After solving the differential equation of beam motion under the appropriate initial and boundary conditions, all parameters that characterize the stress-strain state of the structure in time can be determined.