A High Order Nonlinear Study to Evaluate the Seismic Response of Rotating Machines-Structure-Soil Foundation Systems

• Published in: Journal of earthquake engineering : JEE Vol. 25; no. 14; pp. 2775 - 2807
• Main Authors: Vicencio, Felipe, Cruz, Ernesto F.
• Format: Journal Article
• Language: English
• Published: Abingdon Taylor & Francis 06.12.2021; Taylor & Francis Ltd
• Subjects: Bearings; Earthquake loads; Finite element method; Ground motion; Mathematical models; Modelling; Nonlinear Analysis; Rotating machinery; Rotating Machines; Rotors; Seismic response; Soil; Soil structure; Soil-Structure-Machine Interaction; Soils; Time History Seismic Analysis
• ISSN: 1363-2469; 1559-808X
• DOI: 10.1080/13632469.2019.1651422

Despite the significant advances in finite-element modelling of structures, the soil-structure-equipment interaction is not often accurately accounted due mainly to the nonlinear behaviour of the rotatory equipment. In this paper, different high order nonlinear models are assessed, in order to represent the seismic interaction between the foundation and the rotating machine. Different levels of complexity to represent the response of the equipment and their interaction with the structure are used. A set of 20 artificial ground motion has been considered (horizontal + vertical action), with different frequency contents and peak ground acceleration, to calculate the time-history analysis of the system. The results show that for element's forces and accelerations, the behaviour of the structures analysed is not very sensitive to the type of modelling chosen. Results also confirmed that it is possible to perform a simplified model of the rotor and their bearings to get a good estimate of the seismic loads applied on the foundation. The displacements on the bearings tend to be underestimated by the simplified models, just like the deformations of the rotor. This can lead to wrong design decisions if inappropriate models are used.