超大型离心机基础自振特性研究

某超大型离心机基础埋置于复杂软土地基中，自振特性研究十分关键。分别建立离心机基础的等效土弹簧模型和实体地基模型，对比分析不同地基模拟方法下的模态分析结果；开展基于白噪声激励的动力时程分析，分析地基参振质量对自振特性的影响。结果表明：超大型离心机基础前两阶模态振型分别为水平横向和纵向的摆动；基于不同的地基模拟方法计算得到的振型结果一致，自振频率相差在10%以内；超大型离心机基础结构的前两阶地基参振质量分别为1.376倍和0.998倍的基础总质量，地基参振质量使得结构的振动响应幅值下降50%左右，频谱峰值频率减小约2 Hz。结论对大型埋置式动力机器基础的自振特性研究具有指导和参考意义。

Vibration characteristics of super large centrifuge foundation

A super large centrifuge foundation was buried in the soft soil. the vibration characteristics research was very necessary and important. The equivalent soil spring model and structure-soil coupling model were established to compare and analyze the vibration characteristics based on different foundation simulation methods. The dynamic time history analysis was carried out base on the white noise excitation, to analyze the influence of the foundation participating mass on the vibration characteristics. The results show that: (1) The first two modes of the super-large centrifuge foundation are horizontal and vertical swings.(2) The vibration modes obtained by different foundation simulation methods are consistent, and the natural frequency difference is within 3%. (3) The foundation participating mass of the first two modes are 1.376 times and 0.998 times the total foundation mass respectively; considering the influence of the foundation participating mass, the vibration response amplitude of the structure is reduced by about 50%, and the peak frequency of the spectrum is reduced by about 2 Hz. The conclusions have guiding and reference significance for the vibration research of the embedded large scale power machine foundation.