Changes of Natural Frequencies of Industrial Steel Hall due to Simplifications of Numerical Model

Abstract

The paper presents changes of natural frequencies of industrial steel hall due to simplifications or changes of numerical model. Firstly, the natural frequencies were calculated for basic Variant A of the numerical model of the steel hall which consisted of the main frames, footings, roof purlins and girts. In this Variant columns were fixed at bases, both purlins and girts were rigidly connected to main frames and designed as continuous beams. Then, in Variant B of the model columns were pinned at bases. Next, in Variant C different types of connections (semi-flexible joints) of roof purlins and girts with the main frame were implemented. Finally, in Variant D, soil-structure interaction was taken into consideration. The calculations of the dynamic characteristics of four abovementioned Variants of the numerical model of the hall showed that simplifications or changes of some details of the structure could result in significant errors in values of natural frequencies.