Comparison of pseudo-static and modal spectral seismic analyses of motor-driven pump units: is 1.5 security coefficient of pseudo-static method relevant?

Sylvie Audebert (1, 2) , Damien Rousseu (2)

1 IMSIA - UMR 9219 - Institut des Sciences de la mécanique et Applications industrielles
2 EDF R&D ERMES - ElectRotechnique et MEcanique des Structures

In the framework of the seismic verification of plant equipments, the determination of the seismic loads applied to motor-driven pump anchorages is optimised. A rough justification is usually first performed using the 1 degree-of-freedom pseudo-static analysis, including a 1.5 multi-mode factor. The question is asked about the opportunity to decrease the multi-mode factor value, by comparison to response spectrum analysis, here considered as the reference method. Comparative seismic analyses are performed on more and more complex dynamical systems and excitations; seismic responses of a thin square plate, motor, pump, motor-driven pump unit, connected or not to suction and delivery pipes, are thus successively determined, under 1D and 3D excitations. Two different motor-driven pump units are studied: flexible with vertical axis and stiff with horizontal axis. The quantities of interest are the shearing and tearing loads, deduced from seismic loads at anchorage points.

Domaines: Sciences de l'ingénieur [physics]; Acoustique [physics.class-ph]; Mécanique [physics.med-ph]; Vibrations [physics.class-ph]; Traitement du signal et de l'image [eess.SP]

Sylvie Audebert, Damien Rousseu. Comparison of pseudo-static and modal spectral seismic analyses of motor-driven pump units: is 1.5 security coefficient of pseudo-static method relevant?. Surveillance, Vishno and AVE conferences, INSA-Lyon, Université de Lyon, Jul 2019, Lyon, France. ⟨hal-02188552⟩