Actions of explosive loads of the protecting designs taking into account vibration combustion

Abstract

Emergency explosions inside room (EIR) cause significant damage. The public increasingly reacts to them. The resident and industrial buildings are not counted on the action EIR in Russia despite the fact that industrial buildings can be recognized explosive. The use of safety structures (SS) is the only way to reduce the impact EIR. The action of SS is studied experimentally and theoretically exclusively for case of a quasistationary explosion and constant burning rate . In presented article the influence of the acceleration of burning and wave effects on the formation of explosive loads on the enclosing structures at EIR is studied. In particular, vibrational combustion is studied that generates standing waves and case of acceleration of combustion with the formation of blast wave. Standing nonlinear acoustic waves are generated against the back-ground of excess pressure and the outflow of gases at vibrational combustion. The pressure in standing waves is approximated by the sine. The frequency of oscillations corresponds to the basic mode of oscillation of the volume of hot explosive products. The amplitude of the oscillations depends on the geometric shape of the volume and the rate of explosive combustion at the onset of vibration combustion. Pressure perturbation from vibrational combustion are superimposed on the pressure profile of a triangular shape at the moment of maximum pressure. Profile is characterized by rise time and pressure drop time. So the formed lead acts on a system with elastic deformation with a concentrated mass. The maximum deformation and the coefficient of dynamism of the system are determined depending on the ratio of the frequency of the pressure oscillations in the acoustic oscillations of the rise and fail time of pressure, and frequency of natural oscillations of the system. The obtained results make it possible to clarify the calculation of the bearing capacity of buildings.