Features of the mechanics of the destruction of concrete components of reinforced concrete structures under dynamic impact
Reinforced concrete building structures, especially those used in transport facilities, are subject to significant dynamic impacts. They are characterized by relatively large internal friction, therefore, taking it into account when calculated for dynamic loads can give a significant economic effect. Many experimental data suggest that internal friction primarily depends on structural imperfections of materials. Even with respect to the materials of the same name, for example, concrete, it is hardly possible to unambiguously characterize the degree of absorption of mechanical energy by them of dynamic influences, given the use of components with different properties in the preparation of concrete and not always normal conditions under which the processes of their structure formation occur. These factors give materials a macro- and microscopic heterogeneity, closely related to the following phenomena that generate internal friction during dynamic processes. Internal friction is caused by local microscopic or submicroscopic fractures that occur during residual deformation of the seal. These are deformations that appear instantly with loading (as opposed to the elastic aftereffect) and cannot be restored (as opposed to instantaneous or acoustic elasticity). The value and consideration of internal friction in dynamic problems is primarily determined by the look at the behavior of materials in the dynamics of structures, in contrast to statics. As a result, internal friction is one of the most important dynamic characteristics of the material and structure. The more it is, that is, the more energy is absorbed by the material under cyclic influences, the ceteris paribus the construction is more beneficial for the perception of dynamic loads.