Verification Analysis of the Degradation of Frequency Parameters Under the Action of Seismic Load

Abstract

The article discusses the results of a numerical study of the effect of local damage to bearing structures on the degradation of frequency parameters during seismic effects. The studies were carried out in the LS-DYNA software package which implemented the nonlinear concrete model — Continuous Surface Cap Model (CSCM). Design models of a building are modelled both with regard to direct reinforcement using volumetric FE (finite elements) and flat FE. The object of modelling is a 3-storey building of cellular framing. The analysis of the results of the conducted studies suggests that the effect of degradation of natural vibration frequencies cannot be estimated in the building modelled by means of bar FE. The degradation is insignificant; the frequency reduction occurs within the limits of errors. At the moment, it is not possible to identify the effect of degradation in the bar model in this formulation. To do this, it is necessary to conduct additional researches, including those with other models of materials. Taking into account certain assumptions, the LS-DYNA software package allows computational studies of the effect of local damage to bearing structures on dynamic characteristics, including those resulting from an earthquake.