METHODOLOGY OF OBTAINING DIAGRAMS OF CONCRETE DEFORMATION UNDER DYNAMIC INFLUENCE

Abstract

The methodology of establishing diagrams of concrete deformation under the action of dynamic influences is given. The necessary parameters are determined by iterations. The technique is to find the necessary diagram of the deformation of concrete under compression or tension. It is proposed to determine the main parameters of deformation diagrams under the action of dynamic influences from energy positions on the basis of deformation diagrams under static loads. From the energy standpoint, the energy expended on deformation under static loads must correspond to the energy expended under the action of dynamic loads. This principle allows to obtain diagrams of deformation under dynamic influences on the basis of parameters of diagrams under static load. This allows from a single theoretical position to obtain the parameters of the deformation diagrams for different types and compositions of concrete, and then perform the calculation of elements and structures from them on the basis of a universal deformation model. The possibility of obtaining compression and tensile deformation diagrams is shown.

The proposed technique allows to more accurately determining the dynamic characteristics of materials, thereby providing greater reliability of dynamic calculations, and some savings in materials. Depending on the dynamic impact, deterministic values of dynamic hardening coefficients are set, in contrast to the average value of 1.2 adopted for all types of dynamic loads, which is proposed in most developed methods of calculating the dynamic effects. The reliability of the above methodology was confirmed by comparing the ultimate deformations of concrete determined by the above methodology and by empirical expressions obtained by processing experimental data.