Abstract

© 2019, © 2019 Taylor & Francis Group, LLC.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.