Modal analysis of a large-span building with different boundary conditions

Abstract

The authors present the results of a modal analysis of finite element models of a large-span building with a cylindrical-and-slab roof as a large mechanical system. During the numerical study, the following spatial models are considered: 1) superstructure - fixed-end; 2) superstructure - pile foundation - soil base. The purpose of the study is to compare the results of a modal analysis of the design of a large-span building with different boundary conditions, physical and mechanical properties of the soil base. Modal analysis of a large-span building with a cylindrical-and-slab roof was carried out using the Femap NX Nastran CAE-class software package implementing the finite element method. The authors compare the frequencies and modes of natural oscillations of the construction of spatial models obtained on models of types 1 and 2 of the large-span building with a cylindrical-and-slab roof. As a result of the modal analysis of model 2, the influence of the physical and mechanical properties of the soil base on the characteristics of the structure's own oscillation was revealed. In the prospect, it is proposed to conduct a dynamic analysis of a large-span building with a cylindrical-and-slab roof for seismic effects.