Experimental and numerical cross-correlated modal analysis of the floor structure dynamics in a thermal power plant

Abstract

This article presents search methodology after the cause of excessive floor vibrations in a thermal power plant control room. The floor structure is a composition of a steel grillage and concrete slabs at 12 m level above soil. It was detected that floor vibration severity exceeds the threshold of the permitted rate. After full scale measurements are conducted on site, the results are arranged versus time and frequency domain. In parallel to site measurements a 3D modal analysis is performed in ANSYS. The outcome is a set of modal frequencies and modal shapes. Cross-correlated analytical and experimental analysis formed a true picture of the excitation, response and their mutual interaction. The obtained results and appropriate conclusions had profiled a remedy strategy to mitigate the severity of the floor vibration.