LIMITS OF THE APPLICATION OF THE QUASISTATIC METHOD OF CALCULATION FOR THE ACTION OF AN EXPLOSIVE WAVE
DOI:
https://doi.org/10.31713/budres.v0i46.17Abstract
The Ukrainian normative document adopts a quasi-static method for calculating the action of a shock wave from an explosion. This method involves the use of an equivalent static load. However, this method does not take into account the dynamic nature of the process. When using the quasi-static method, the equivalent load is accepted without taking into account the geometric and physical-mechanical characteristics of the enclosing structure. Therefore, the equivalent load is accepted incorrectly.
It is shown that the dynamic coefficient depends on the span and cross-sectional dimensions. When assigning an equivalent load, these factors must be taken into account. When calculating one class of structure, the dynamic coefficient can differ significantly depending on the material, rigidity, span. Accordingly, the equivalent static load must also be different.
It is shown that the form of change in blast wave pressure over time affects the displacements and forces of the structure on which this wave acts. An analysis of the form of change in blast wave pressure over time is carried out.
It is shown that when an explosive load acts on a reinforced concrete beam, the equivalent static load can be both less than that regulated by regulatory documents, and more. It depends significantly on the span of the beam, its rigidity, as well as its own mass and the floor on the floor.
The article presents a method for engineering calculation of the beam using the Lagrange equations of the second kind. This makes it easy to obtain the maximum value of the dynamic coefficient.
To reduce the dynamic impact of the blast wave, it is recommended to increase the mass of the floor in any way. In addition, it is recommended to increase the span of the beams.
It is also shown that with a nonlinear dependence of the action of the blast pressure over time, the dynamic coefficient decreases, which should also be taken into account when designing
