About the author:

China Energy Engineering Group Jiangsu Power Design Institute Co., Ltd., Nanjing, Jiangsu 211102, China

Abstract:

The dynamic characteristics of turbine foundations are critical to operational stability,necessitating strict control of foundation vibration amplitudes. A finite element model of a large-capacityturbine foundation is established using ABAQUS software. Modal analysis is conducted to extract thefoundation’s natural frequencies and modal shapes within a 0~70Hz range,while the mode superpositionmethod is applied to calculate the amplitude response at control points on the foundation’ s top surfaceunder disturbance forces. The research results show that the foundation’ s vibration modes within a 0 ~70Hz range are predominantly characterized by top-plate vibrations. The dominant modal frequencies（4.77~ 24.56Hz） are significantly lower than the machine’ s rated frequency（ 50Hz）， effectivelyavoiding resonance risks. The maximum vibration amplitudes on the foundation’ s top surface （11.5μmin x direction, 16.0μm in y direction, and 12.6μm in z direction） are all below the limits specified inthe relevant standards, and amplitudes remain below 8μm within the 50Hz±5% frequency range,achieving a safety margin of 60%. The design of the frame-type reinforced concrete foundation structure isreasonable.