DYNAMIC EFFECTS BY THE STRUCTURAL DAMAGE OF THE BUILDING STRUCTURE

Abstract

Purpose. To review the standards and the scientific literature on emergency load calculations that are linked with stability to progressive collapse of building structures and dynamic influence of localized structural component damage (failure) on the building structure. To study the dynamic influence on the building structure of its localized structural component damage by laboratory experiment and numerical simulation. Methodology. To reach the goal the existing standards and the scientific literature of different countries on calculations and design of resistant to progressive collapse buildings and structures were reviewed. The laboratory bench was created. Experimental and numerical studies were conducted by modelling dynamic behaviour of the building structure. The laboratory bench was statically indeterminate system in order to localized structural component damage (failure) did not lead to the hole structure destruction but only to its qualitative reconfiguration. Findings. During the laboratory experiment the vibrational accelerations and displacements for characteristic point of structure were registered. By processing vibrational diagrams, the values of the frequencies and the laboratory bench free vibrations logarithmic decrements were received, as well as the value of the dynamic increase factor by different load levels and different failure types. Experimental results were checked by numerical simulation. Originality. The studies allow to evaluate dynamic effect of localized structural component damage two types. It was also discovered that the values of dynamic displacements and accelerations may be differentby several times by the comparable values of the dynamic increase factors of different failure types. Practical value. The results suggest that in the case of total structural component failure the value of dynamic increase factor (stresses and accelerations) is more than that in the case of structural component damages while retainingpartial functionality. In such a case when carrying out practical engineering calculations it would be sufficient to consider the total structural component failure while the possibility of partial damages would be as reserve of power.